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With all that has been going on in the world and all the important societal problems, I have been despairing that my desire to push for a natural history museum and more evolution education seemed not as important. But it struck me today that it is perhaps one of the most important things we need to do. There are a lot of misunderstandings about evolution, even among people who accept it, that hinder our ability to get along in the world. Understanding two important truths of evolution will go a long way towards healing our societal divides. What are those truths? 1. We are all the same, and that is a good thing. 2. We are all different, and that is also a good thing. These may seem contradictory, but if you understand how they are meant, they make perfect sense.
- We are all the same, and that is a good thing.
When you start really studying life on this planet, it quickly becomes inescapable that we are all connected. We are all part of the same family. Strip off the skin from humans and we see essentially the same underneath. We all share the same skeletons, our muscles and organs are the same, there are no important differences in our brains. Sure, there are differences, but no matter what way we try to divide humans, especially by skin color or nationality, we find that the differences within the groups are greater than the differences between groups. What this means is that the dividing lines are arbitrary and have no biological basis.
When we go beyond humans and look at all vertebrates, we see the same thing. If we compare skeletons, we see the same bones over and over again. Every animal that has four limbs shares the same bone structure. They may look different, but the bones are all the same. All of our front limbs have a humerus, an ulna, and a radius. We all have the same number of fingers and toes. They may look different, they may lose some as they grow from fetus to adult, but they are all there. As we get farther and farther away from direct ancestry and relationships, the superficial differences start piling up, but the core is always the same.
Going even farther, we all share the same base code. We all use essentially the same DNA and RNA. The sequences may be different, but just as all computer programs are different, they all share the same underlying coding language. We all share metabolic pathways, from bacteria to humans.
Why do we see all these similarities? Because we all share an ancestor. Somewhere down the line, we are all related. We are one family. It may be a very extended family, but we are all together. All life on Earth is connected. Through that life, we are all connected to the very rock upon which we stand. Life has shaped the surface of the Earth. It has shaped the air we breath. We all sprang from the same roots. When you look at someone from a different culture, someone with a different skin color, you are not seeing an other, you are seeing a long separated family member. Embrace that connectedness. Now, I know that no one can get more under your skin and angry than a close family member, but at the end of the day, we don’t generally let that tear us apart. No matter how much we may disagree with our family, we still recognize they are family. Just take that feeling and extend it to recognize that every living thing on Earth is also part of your family.
2. We are all different, and that is a good thing.
So if we are all essentially the same, how can we all be different? No matter how closely we are related to someone, there are always differences. Even identical twins are not completely identical. Our DNA and life experiences mean that each and every one of us is different in some way from everyone else. While we all share the same basic body plan and organization, there are always some differences.
Those differences are important. Ask any agricultural scientist and they will tell you that one of, if not the biggest danger in our food supply is the monoculture crops we grow. When everything is the same, that means they also share all the same limitations and vulnerabilities. Monocultures only work when there is no change. But they do not handle change well. And if there is one thing we know about life, it is that change is inevitable. These days, we are pushing change faster than ever before, so this vulnerability to change is deadly.
Purity is the death of a species. We need diversity to weather changes. As new diseases crop up, as weather becomes more unpredictable and changeable, we will need the diversity to be able to handle whatever is thrown at us. The more diverse the population, the more changes we can tolerate. In a diverse population, there will always be some fraction of the population that is prepared for anything that happens. Those people will make sure that we continue. Moreover, they will help those of us unprepared for the changes make it through. When a new disease appears, those that are naturally immune will be key to developing medicines that will allow the rest of us to survive. Those that can handle climatic changes will be the ones to build the structures and infrastructure that will allow the rest of us to weather the storms. We need diversity. If we try to homogenize our culture and our people, we will die.
We need evolution education and a natural history museum.
So how do we get people to understand this? First of all, on a broad scale, we need to teach people a proper understanding of evolution and evolutionary theory. But we have to do it in a way that exemplifies its importance in our everyday lives. We need to get people to understand why they need to understand it. Evolutionary theory affects us every day. People need to understand how.
We need natural history museums for a multitude of reasons, but two very important ones apply here. First, they will stand as storage houses of information. They are a public recording of the changes that have taken place and are taking place. Secondly, they are a way to teach people who are not in school. Even if they don’t pay that much attention to the details in the museum, they will see a record of the changes. Museums can be designed to showcase the importance of evolution, the advantages of diversity, and the dangers of reducing that diversity. Museums are one of the most trusted sources of information. We need to leverage that to showcase both the interconnectedness of life on Earth and its diversity and why that has allowed its continued existence. It also can showcase what happens when that diversity is not there.
One may argue that history museums would be better at this. The advantage of history museums is that it makes it personal and easy to make it easy for people to relate to it. The disadvantage is that it makes it personal and easy for people to get defensive about it. Natural history museums can teach these lessons on a canvas that people can view and learn from more dispassionately, without it feeling like a personal assault upon their culture that can often happen in history museums.
To be sure, many people will feel that any mention of evolution is an assault upon their worldview, so I am not advocating the idea the natural history museums are inherently better. Instead, I am advocating the view that all types of museums work better when there is a diversity of museums that can tell the stories from different angles. Without a natural history museum, we lack an important viewpoint in the public arena. By building a museum network, we can spread the ideas much more effectively. A natural history museum will not hurt other local museums. It will help all of them. We don’t need just a natural history museum. We need a natural history museum, a local history museum, an international history and cultural museum, an art museum, and other museums. In Arkansas, we have some of the history, art, and culture, but we do not have a natural history museum. As such, we lack that long and broad view that can only come from an understanding of natural history.
On November 4th, I presented a workshop on evolution at the Arkansas Curriculum Conference. The workshop was sponsored by TIES, the Teacher Institute for Evolutionary Science, an organization dedicated to helping teachers teach evolution, itself sponsored by the Richard Dawkins Foundation for Reason and Science.
Unfortunately, the wifi died right at the beginning of my talk, so the videos embedded in the talk were not able to be played. So for those of you who attended, and for those of you who would like to see the talk, I am posting the powerpoint file here. I know, it is incredibly overdue, but in my defense, the world took a sharp turn into weirdness right afterwards and then we had Thanksgiving. Any of you who are teaches or students also know what a crazy time of year this is. At any rate, here is the powerpoint. I will see about trying to record some audio for it at some point, along with the other talks I have meant to put up. We will see how that goes over the holidays.
If you go to the TIES website, you will see a version of this talk. I have modified it to include more information on fossil formation, which I skimmed over, for the most part, in the workshop itself. I focused more on the slides discussing why learning evolution is important in the first place. It has far more everyday impacts than most people imagine and is well worth understanding even if one believes in creationism or doesn’t care about esoteric biological concepts at all (for instance, if you are a cutting edge software or robotics designer).
In addition, there are a couple of other things I wanted to post. First is an icebreaker activity that TIES provided. In this activity, participants determine whether or not a series of statements about evolution are true or false. In a twist that catches most people off guard, they are ALL false. They are all commonly held beliefs about evolution, but they are all wrong, which makes a good way to start a conversation about the topic.
Here are the statements and a very brief explanation of why they are wrong, as supplied in the document. Further clarifications and discussions are happily supplied upon request.
1. Charles Darwin developed the theory of evolution.
The theory of evolution existed before Darwin; it was Darwin’s Theory of Evolution by Natural Selection that became widely accepted.
2. Living things adapt to their environment.
As a whole, living things are adapted to their environment. Individuals are unchanging, they either live or die based on the traits they are born with.
3. Biologists “believe” in evolution.
Science is not based on belief. The theory of evolution provides a model for scientists to understand the relationships between organisms on the planet.
4. Monkeys will eventually become human.
There are many species of primates and all are adapted to their environment. A chimpanzee would not turn into a human over time anymore than a cheetah would turn into a lion (or vice versa).
5. Evolution is JUST a theory.
Saying that it is “just” a theory implies that it is a guess, or that its not well supported. There is much evidence to support the theory of evolution, as well as direct observation of species change.
6. Only atheists accept the Theory of Evolution.
Scientists of many religions across the world accept evolution, and do not find it incompatible with their faith.
7. If evolution is disproven, creationism must be true.
A problem with logic (disconfirming evidence). Even if you disproved evolution, you would have to develop and support another model of organism diversity. Disproving one, doesn’t
prove the other.
8. No one has ever seen evolution happen.
In organisms that reproduce quickly (like bacteria) changes in species can be directly observed, such as resistances to antibiotics.
9. Order cannot come from disorder, so evolution is false.
Many instances in nature show molecules and substance organizing, such requires energy. The sun provides the energy that ultimately fuels all of life’s processes.
10. There is evidence that dinosaurs lived with humans.
There is no evidence that suggests humans and dinosaurs lived at the same time.
11. Scientists regularly debate that evolution occurs.
Scientists debate elements of evolution, relationships between organisms, and fossils. The only place the evolution debate really happens is in the social settings.
12. Creationism is a valid scientific theory and should be presented with evolution. Creationism violates the scientific principle of natural causality.
13. There are no transition fossils. Museums are filled with fossils that show intermediate species.
14. Carbon dating is not accurate, therefore the age of the earth cannot be determined.
Carbon dating is one of many methods used to date the earth. Taken as a whole, the evidence is overwhelming that the earth is very old.
There is also a dice game that I want to share with you demonstrating how natural selection works, but that will have to wait until next post.
Don’t worry, this isn’t an announcement about advertisers. This is a few short announcements I wanted to make sure people knew about. I mentioned them on the Facebook page, but wanted them in a more permanent location.
The Arizona Center for Evolution and Medicine has been doing a fair bit lately, holding meetings and seminars, getting research going, and such. They have now also started a new blog that is worth people’s time to read called simply the EvMedBlog. Here is what they have to say about it.
The EvMedBlog, hosted by the Center for Evolution and Medicine at ASU, brings together essays by Core CEM Faculty, Guest Experts, and Affiliated Scientists to elucidate human health and disease through an evolutionary lens. Here we will explore mutations in the human genome, host-pathogen coevolution, human physiology across diverse ecological contexts, early life nutrition, and dozens of other topics at the intersections of evolutionary biology, medicine, and global health.
As seen on the EvMedBlog page. Studies of the Arm showing the Movements made by Biceps by Leonardo da Vinci, c 1510 source:wikimedia
I’ve included the new blog on the link page under the science blogs for easy retrieval.
The textbook Functional Anatomy of the Vertebrates, by Liem, Bemis, Walker, and Grande, usually ranks among the top of most anatomists lists of best comparative anatomy texts available. Ok, admittedly, there aren’t that many textbooks out there for comparison, but this one really is well received. What makes it particularly great for educators right now is that all the images in the 2001 book are available as images in Powerpoint slides for free online. They are organized and downloadable by chapter. They files are small and manageable and there is no login or information required. All they ask is that you do please cite the text when you use them, which is a perfectly reasonable request.
Sharks are on the educational menu this summer (surely not on your plate, right?!) at Cornell University and Queensland University in Australia, who are jointly offering a free online course (yes, one of those MOOCs) called “Sharks! Global Biodiversity, Biology, and Conservation“. It starts June 28th and only last four weeks, so it will be over before school starts back in August. It is only scheduled to take 4-6 hours a week, so it is not too time intensive, but it should provide a lot of cool information and resources for educators who want to bring cool current shark stuff into their classroom.
If you haven’t seen the videos on evolution on pbs.org, you should really check them out, along with their other great resources at NOVA Labs, which is one of the best spots on the Net for evolution resources for educators. Finally, there is of course TIES, the Teacher Institute for Evolutionary Science, associated with the Richard Dawkins Foundation for Reason and Science. Their primary goal is to assist secondary school teachers in teaching evolution in their classrooms and they have a fantastic collection of resources. They also sponsor teacher development workshops, one of which I hope to be running myself soon, which I am excited about, so stay tuned for more about that. All three of these can be found on the Links page any time.
That’s all for now, but there is always much more to come.
A couple of weeks ago, I visited Dodd Elementary in Little Rock. After I left, the students wanted more information and sent me several questions. I thought, rather than respond to them individually, I would post the answers here.
Did saber-toothed tigers live at the same time as mammoths in the Ice Age? How old are mammoths?
Yes, they did! They even lived together in Arkansas during the Ice Ages, along with the more commonly found mastodons (which were like the mammoths, but a bit smaller (about the size of modern elephants) and were more adapted for forests than the grassy plains preferred by the mammoths.
What most people refer to as the Ice Age was in fact a series of almost a dozen times in which the glaciers expanded to cover much more land than they do now. This period lasted from about a million years ago to 11-12,000 years ago during what is called the Pleistocene Epoch.
There were actually many different species of saber-toothed cats. The most commonly known is one called Smilodon, which lived between 2,500.000 years ago to about 10-12,000 years ago.
The first mammoths appeared around 6,000,000 years ago, but the Woolly mammoths and the Columbian mammoths (the type that lived in Arkansas), first appeared about 400,000 years ago. They came south from Canada into the United States about 100,000 years ago. While they died out in North America almost 12,000 years ago, there were a few that lived on Wrangel Island near Russia until less than 5,000 years ago.
I wanted to know if cavemen were alive because didn’t the dinosaurs eat them?
All the dinosaurs (except birds) died out over 65,000,000 years ago, but the first humans only appeared around 200,000 years ago. So humans and dinosaurs were separated by an enormous amount of time and never lived together. Humans did live alongside the mammoths and saber-toothed cats during the Ice Ages, though. Humans killed and ate mammoths and humans and saber-toothed cats killed each other (we don’t know if humans ate the saber-toothed cats, but we’re pretty sure they ate us).
How old is coral?
Coral is very, very, old. The first corals appeared over 500,000,000 years ago. However, none of these early types of coral still exist. They all went extinct (died out) and were replaced by types of coral that evolved (descended) from them. The modern corals that you can see today first appeared in the Triassic Period roughly 200,000,000 years ago (the first dinosaurs appeared about 240,000,000 years ago).
How big is a T. rex egg?
No one knows! No T. rex eggs have ever been found. We can guess they were up to a foot long and up to five inches wide, but that is just a guess based on what we know of eggs that have been found from its distant relatives. What we do know is that T. rex babies were a lot smaller than the adults would have been no bigger than a small turkey.
How long is a sea spider?
Sea spiders, or pycnogonids (pic-no-go-nids), can grow up to 25 cm (10″). They can be found in the southern oceans today. Fossils of sea spiders are rare, but have been found as far back as the Cambrian Period almost 500,000,000 years ago. Even though they look something like spiders, while they are arthropods like spiders, they are not really spiders and occupy their own group within the arthropods. They are very strange animals, with most of their organs in their legs.
I think you may have been referring to a different animal though, the sea scorpions, which was part of the fossil collection we saw in class. Even though they are called scorpions, they are not true scorpions, although they are related to them. These animals, called eurypterids (your-ip-tur-ids), were mostly no more than 30 cm (12″), but could get almost 2.5 meters (8′), making them the biggest arthropods ever known. The earliest fossils we have found were dated at 467,000,000 years, but they may have first appeared over 500,000,000 years ago. They died out at the end of the Permian Period just over 250,000,000 years ago, along with most of the life on the planet at the time.
What is the shortest sea dinosaur?
While there were sea-going reptiles, there were no sea-going dinosaurs that we know of. The closest that we know of right now were the spinosaurs, which spent much of its time wading in relatively shallow water. These dinosaurs were huge, some of them approaching 15 m (50′) or more, with the smallest ones only a modest 8 m (26′).
Of the sea-going reptiles, the most common ones were the dolphin-shaped ichthyosaurs (ick-the-o-sores), the lizards called mosasaurs (literally lizard, they evolved from monitor lizards like the Komodo dragon), the generally short-necked and big-headed pliosaurs (ply-o-sores), and the long-necked plesiosaurs (please-e-o-sores, for the purists, plesiosaur can also refer to both pliosaurs and the more traditional plesiosaurs because the larger group containing pliosaurs and plesiosaurs is named after the plesiosaurs. yes, it is a bit confusing). And of course we can’t forget the sea-going crocodiles called metriorhynchids (met-re-o-rine-kids).
The smallest ichthyosaur, or “fish-lizard” named Cartorhynchus (cart-0-rine-cuss) was less than 0.5 m (15″) long. it was also the oldest known one at almost 250,000,000 years old. You may notice that the picture below says the smallest was 70 cm, but an even smaller one was found.
Dallasaurus (“Dallas lizard”), the earliest known mosasaur, was also the smallest mosasaur at no more than 1 m (3′).
The smallest plesiosaur was just over 1 m (3′).
Thalassiodracon, or “sea dragon”, probably the smallest known and most primitive pliosaur, was 1.5-2 m (5-6.5′), so slightly bigger than its relatives, the plesiosaurs. All of the marine (sea-going) crocodilians were more than 2 m (6 ‘) and would have eaten the others, so we can rule them out for shortest marine reptile from the Mesozoic Era during the age of dinosaurs.
There is another group of marine reptiles that was also common during the Mesozoic, although they are not so widely known. The thallatosaurs, which literally means “ocean lizard” were as small as 1 m (3′). Finally, there was a sea turtle-like group called placodonts, of which the smallest were just under 1 m (3′).
Notice that most of them all start off at roughly 1 m, except for the ichthyosaurs, which started off at less than half of that, so the winner for shortest sea reptile of the dinosaur age is the ichthyosaur named Cartorhynchus.
What is the longest sea dinosaur?
The undisputed king of the marine reptiles was the ichthyosaur named Shonosaurus, also known as Shastasaurus, which reached 23 meters (75 feet).
The longest mosasaur is, coincidentally, Mosasaurus itself, potentially reaching lengths of 18 meters (59 feet), so not as big as Shonosaurus. This animal used to live in Arkansas. According to the most official statements, the mosasaur in Jurassic World was 22 meters (72 feet), so bigger than the real ones, but not by a terribly large degree, and still smaller than Shonisaurus.
The longest pliosaur was no more than 18 meters (59 feet), while the longest plesiosaur was no more than 15 meters (49 feet), so none of them come close.
How did they breathe underwater?
It does seem like animals who live in the sea should be able to breathe underwater, doesn’t it? But the aquatic (a fancy word for living in the water) reptiles didn’t. Like all reptiles, they had to come up to the surface to breathe. This is true for any reptile that swims in the ocean, including sea turtles and marine iguanas. The same is true for their distant relatives, the birds. Penguins have to breathe air, even though they can dive deep. It is also true for all mammals, such as whales and dolphins. So how do they dive underwater and stay underwater for so long? They hold their breath, just like we do when we swim. Only they are much better at it than we are and can hold their breathe for a long time.
What is the longest land dinosaur?
That is an excellent question. The problem is that we have no fully complete skeletons of the largest dinosaurs, so we have to estimate their sizes from the bones we have.
As you can see on the chart above, there are several dinosaurs that are similar sized. Diplodocus and Supersaurus got up to 33.5 meters (110 feet). Argentinosaurus got upwards of 35 meters (115 feet) or more. Bruhathkayosaurus (Bru-hath-kay-o-sore-us) was possibly around this size as well, but the fossil material is too little to get a good estimate and what we had has disappeared. However, the American Museum of Natural History in New York has recently put on display the largest dinosaur ever displayed and possibly the largest dinosaur ever known at over 37 meters (122 feet).It doesn’t even have a name yet and is just called the AMNH titanosaur. Of course, the biggest dinosaur ever found is so little known that it has become almost mythical. Amphicoelias has been estimated to have been as long as 58 meters (190 feet). Unfortunately, all that was found of this animal was a few bones, including a vertebra that stood 2.7 meters (8.9 feet) tall. The bones were very fragile, in very poor condition, and were preserved in mudstone, which crumbled easily. All of the fossils vanished (possibly crumbled away and swept out), so all we have left is a few drawings and measurements of the bones.
How big was Apatosaurus?
According to the fossils we have, Apatosaurus typically got around 22 meters (72 feet), but could have gotten as long as 27.5 meters (90 feet). Weight is a very difficult thing to estimate for many reasons, but most estimates place an adult Apatosaurus somewhere between 20-40 tons (40,000-80,000 pounds, 18000-36000 kg), or about the weight of 4-8 adult elephants.
What is the shortest land dinosaur? What is the smallest dinosaur?
That depends on what you consider a dinosaur. Anchiornis was estimated to be 34 cm (13″) long, but was a young adult, so probably got at least 38 cm (15″). But some consider Anchiornis to be an avialan, the earliest group of birds. Parvicursor is the smallest known adult dinosaur that is definitely not a bird according to some people, at 39 cm. Epidextipteryx was only 44 cm (17″) if you include the tail feathers, but only 25 cm(10″) if you don’t include them. However, Scansoriopteryx, also known as Epidendrosaurus, was only about 16 cm (6″), but we only have young ones that would have grown larger, but we don’t know how much larger. Epidextipteryx and Scansoriopteryx may look like birds, but were actually in a different group of dinosaurs. If you consider modern birds, the bee hummingbird takes the prize as the smallest known dinosaur at less than 6 cm (2.5″) and weighing less than 2 grams, just over the weight of a single penny.
But if you are talking about shortest, meaning how tall they stood, that is harder to work out because it would depend on how they stood, but none of these animals would have stood taller than 20cm (8″) at most.
For comparison, these dinosaurs were about the size of a common crow or perhaps even smaller.
Can an 8 feet tall person be as tall as a dinosaur?
A person standing 8 feet tall would be taller than a lot of dinosaurs. A baby just learning to walk would be bigger than some dinosaurs. If we include modern birds, which are also dinosaurs, there are some dinosaurs that a new born baby could hold in their hands (the bee hummingbird is less than 2.5″ long and more than an inch of that is taken up by the beak and tail feathers).
When did the dinosaurs live? When were they born?
The earliest known dinosaur is Nyasaurus, which was found in rocks thought to be 243,000,000 million years old during the Triassic Period, the first part of the Mesozoic Era. There is some uncertainty if this was an actual dinosaur, so if it wasn’t, that would make dinosaurs like Herrerosaurus and Eorapter (both of which looked similar to Nyasaurus) the oldest dinosaurs at about 230,000,000 years old.
When did the dinosaurs die?
Everything that most people call dinosaurs died out at the end of the Cretaceous Period, the third part of the Mesozoic Era, about 65,500,000 years ago. However, they didn’t all die out. One small group of dinosaurs survived, which are the birds. Today, birds are the most diverse group of terrestrial vertebrates (animals with a backbone living on land), so dinosaurs are alive and thriving.
How long did the dinosaurs live?
Dinosaurs were on earth for a very long time. From their beginnings over 240 million years ago to the end of the Cretaceous Period, they lived for around 175,000,000 years. If you include the birds, they have lived for over 240,000,000 years and are still going strong.
If you are talking about individual dinosaurs, they have varied lifespans. Just as you can find mammals that live no more than a year or so to mammals like us that can live over a hundred years old (the oldest known person lived to 122), you can find dinosaurs that lived like that. Some species of hummingbirds only live a few years, so we can expect that some other dinosaurs may have only lived a few years as well. The giant, long-necked sauropods were adults by their teens and may have lived as long or longer than we do. We reall
How old are T. rexes?
If you mean how long ago did they live, Tyrannosaurus rex lived at the very end of the Cretaceous Period, the last period of the Mesozoic Era, 68,000,000-65,500,000 years ago. If you wanted to know how old an individual T. rex could get, They did most of their growing when they were between 14-18 years old, reaching maturity between 16-18 years old. But they didn’t live long after that. All of them that we know of died before they were 30. Of course, whether or not they could have lived longer than that, we don’t know, but that is the ages of the fossils that we have.
How did the dinosaurs die?
Most of the dinosaurs died out at the end of the Cretaceous Period about 65,500,000 years ago when two major events happened. The first was eruption of one of the largest volcanic events in the history of the Earth. The volcanoes that formed the Deccan Traps in India were so massive, the rocks from the lava put out by these volcanoes are over 6000 feet deep. These eruptions happened over tens of thousands of years, maybe even millions of years.
But that wasn’t the worst thing. An asteroid hit in Mexico at the same time as the volcanic eruptions were taking place. It was estimated to be about 10 kilometers (6 miles) across and left a crater more than 100 miles across. Remnants of the crater can still be seen in Chicxulub, Mexico. If all the nuclear bombs in the world were exploded at the same time, it would not be as powerful as the impact of that asteroid.
Did some animals live after the volcano and meteor?
Amazingly enough, yes. If they had not, we would not be here. Every form of animal suffered heavy losses, but most did not die out completely. One small group of dinosaurs survived, which became the birds. A lot of mammals died out, but a lot also survived. Amphibians and crocodilians did reasonably well. Anything small, able to take shelter, and lie dormant (like squirrels hibernating in the winter) to conserve their energy and ride out the tough times did ok. In the oceans, anything large, needing a lot of food, or having shells had a hard time.All the large sea-going reptiles died out. Virtually all the shelled cephalopods (squid relatives) went extinct, but their unshelled relatives survived. Tiny organisms called plankton that lived in the ocean and made their shells out of calcium carbonate died out and were replaced by types that used silicon for shells. During the Cretaceous, the ones with carbonate shells were so common, when they died, their shells piled up and became huge layers of chalk, forming what became the famous White Cliffs of Dover in England and the chalk beds in southwestern Arkansas, among other places. But they almost all died out during the volcano and meteor impact and never became nearly as abundant ever again. The reason for this is because the asteroid and volcanoes released so much carbon dioxide and sulfur into the air that was soaked up by the oceans that the oceans became very acidic and lost a lot of oxygen. So anim
Of course, insects of all sorts survived, as did a variety of invertebrate animals like snails, clams, starfish and the like. But all of them took severe losses, especially those that were specialized to eat only certain plants or animals. One that had a more varied diet managed to survive.
How was it there? Was it dusty or cold there?
During the Mesozoic Era, the time of the dinosaurs, it was, in general, warmer than it is now and the temperature differences between seasons were not as extreme as today. The north and south poles were not permanently frozen over during this time like they are now. But much like today, there were all types of weather and environments. It was hot and dry in some places, it snowed in other places. There were swamps and prairies, forests, deserts, almost any environment you can think of existed then. The only environment you might not find would be glaciers, but you could probably even find them near the tops of mountains at times. Of course, they didn’t exist in the same place on earth and there were different dinosaurs that lived in different areas.
Also remember that the Mesozoic covered an immense span of time, so the earth changed during this time.
Why didn’t the dinosaurs need to fly?
Some dinosaurs did fly, but most didn’t. Most animals today don’t fly either. I expect most animals would if they could, but it takes a lot of changes to evolve the ability to fly. As animals evolve, they can’t decide they are going to develop flight. Small changes will appear in individuals from time to time and if those changes are helpful (or at least not harmful), then they get passed on and can spread through the population. To develop flight, a large number of changes have to happen, so only a few types of animals have evolved in the right way to develop flight. Once they did though, it was very effective, which we can tell by looking at the large number of birds and insects and even bats that can fly.
Is it true that fish had sting rays?
There are some fish called stingrays and they do indeed have venomous spines on the tail, which can be painful and occasionally deadly if they sting someone. They only use them in self defense though, so they won’t hurt anyone unless they feel threatened.
Stingrays are common today and can be seen in many aquariums. But they are also found as fossils and have been around for millions of years. We have even found fossils of stingrays in Arkansas. They do not have bones like we do, but we do find lots of their teeth, which look like flat rectangles. They use these flat teeth for crushing shells of clams and other animals.
What was the tiny thing at the bottom of the smart board?
I’m sorry, I don’t know what you are referring to. Was it on the timeline? Please let me know and we can figure it out.
How many bones have you found?
I have found lots of shells and crinoids. I have found a handful of shark teeth. But I haven’t found too many bones. When I was on a dig in Argentina, I did find a pelvis (hip bones) of a sauropod (the giant, long-necked dinosaurs). I also found part of a skeleton of an archosauromorph (the ancestors of crocodiles and dinosaurs). When I worked in Wyoming and Colorado, I found several fossil turtle shells and part of the horn of what may have been a uintathere or some similar animal (rhino-like mammals with knobby horns and bumps on their heads). I also found several tiny bones of rat-sized mammals. I don’t know what they were, but I remember one place where the bones looked like turquoise (a greenish-blue gemstone).
What I would really like to find would be a dinosaur in southwestern Arkansas, although the skull of a mosasaur or elasmosaurus would be a close second. There are opportunities for finding fossils in most of the state, so keep looking and let me know if you find something!
Wow. I can not believe that I have not posted anything here since Halloween. My New Year’s Resolution is to not let that happen again. I have no excuses. But as was said on the Syfy show The Expanse, “We can not change the things we’ve done, but we can all change the things we do next.”
For this post, I want to relate the trip I took to Arkadelphia just before the Christmas holidays to visit the Goza Middle School on the invitation of one of their science teachers, Trent Smith. That trip will benefit many people in the future, and it also provided a chance to see some Arkansas geology and paleontology that may prove interesting to fossil enthusiasts.
This all started with an email I got from Trent Smith, who had found some fossils he wanted help identifying. After looking at the attached photo, I tentatively identified most of them as specimens of Exogyra ponderosa, a common oyster from the Cretaceous Period. There also appeared to be a goniatite ammonoid, a Cretaceous Period cephalopod, or squid relative. I could not be sure just from looking at the pictures, so I offered coming down to take a look at them in person. Trent was amenable to that and after a few emails back and forth, we arranged to not only look at his fossils, but talk to his eighth grade science class while I was there. It turned out that the school was interested in me talking to multiple classes, which all told was about 160 students. They suggested I could either give one talk to all of them at once, or I could do multiple talks to individual classes. I much prefer the smaller groups where people can get a more hands on experience with the fossils and have more opportunity for students to ask questions, so I opted to give several talks. I wound up giving seven talks, with two of the talks to combined classes. So I had the opportunity to speak with a lot of students.
When I got there, Trent helped me bring in my boxes and took me to his room to start setting up. Goza Middle School students are fortunate to have great science teachers who are passionate about science and education. Trent’s classroom fossil collection was by far the largest fossil collection I have ever seen in a public school classroom. They have a good variety of most of the invertebrate fossils that can be found in Arkansas. They also had a fabulous nautiloid ammonoid 4″ across or more. I had a shell of a modern Nautilus, a genus of the only extant ammonoids, so the students were able to compare a modern version with one over 70 million years old.
For each class, I gave a short introduction to the fossils that can be found in the state, which is much more diverse than most people realize. I also gave them a quick demonstration of the immense expanse of time we were discussing. I have a timeline that stretches eighteen feet and covers 600 million years. People are usually suitably impressed with that timeline, but when I tell them how much space our civilization represents on the timeline, they are stunned. At that scale, all of human recorded civilization is approximately the width of one human hair. Afterwards, we let the students look at the fossils I brought and ask questions. The students were more reluctant to get out of their seats and approach the front table than the younger kids I usually talk to, which I found interesting and speaks to how quickly we train our students to sit and listen without interaction. But once they got over their training, they enjoyed being able to handle the fossils and examine them close up. The students were uniformly polite and well behaved and were a pleasure to talk with. Midway through, the teachers treated me to a tasty potluck lunch.
If everything was left at that, it would have been a great trip and I would be happy to return, but they really went above and beyond. In addition to lunch and a small donation (I have generally not asked for payment for classroom visits in the past and as a result, getting paid for it almost never happens, but getting paid means I can go to more classes so is greatly appreciated), they provided me with even more. They gave me my first two Paleoaerie shirts, which they designed and they did a fantastic job. On the front of both shirts is a dinosaur foot that looks like the foot of Arkansaurus, the only dinosaur bones ever found in the state, and my name, Dr. Daniel. On the back of one shirt, it has the dinosaur foot with the words PALEONTOLOGY above it and DIGGING UP KNOWLEDGE below it. On the back of the second shirt, it says PALEOAERIE.ORG followed by my three statements of what guides my efforts: The universe is endlessly amazing, knowledge is useful only when it is shared, and you can’t really know something unless you understand how and why we think we know it. The shirts are going to be my uniform for future talks.
After school was over, Trent showed me a spot he has collected fossils from on Wp Malone Road, just west of I-30. According to the Arkansas Geological Survey’s geologic map of the Arkadelphia quadrangle, the area is listed as being in the Nacatah Sand, an Upper Cretaceous formation consisting of a mix of unconsolidated sediments deposited in a nearshore marine environment. However, the marl, a limey clay, we found in the creek looked more like it came from the Marlbrook Marl, a formation that lies underneath the Nacatah and separated from it by the Saratoga Chalk formation. The Saratoga Chalk is not thick in this area, so it is quite easy to go from the Nacatah to the Marlbrook in a very short distance. In this particular locale, the Marlbrook is close by and it is likely that what we found was washed downstream to where we found it. As I recall, Trent mentioned that fossils were more common the farther upstream one went, which would support this idea. The Marlbrook Marl, when fresh, is a blue-gray lime clay, or marl, laid down in nearshore, shallow marine environments, just like the Nacatah Sand, but without the sand contribution. The upper part of the Marlbrook is also famous for being extremely fossiliferous and this site was no exception. I initially attempted to collect what I found, but very quickly realized there were so many shells that it was impossible to carry them all. The great majority of what we found were shells of Exogyra ponderosa, but the numbers would have allowed us to quickly fill a crate with specimens. We also found a few snail shells (of what type I am not sure) and a terebratulid brachiopod, but the numbers of everything else did not begin to compare with the shells of Exogyra. On other trips, Trent collected numerous Exogyra shells and gave me two boxes full of shells. Thanks to him, I will be able to supply many Arkansas classrooms with actual Arkansas Cretaceous fossils.
This area is a nice place to collect. As long as one is on public land (or with the permission of the land owner), you can collect any of the invertebrates you want, so you can feel free to collect Exogyra shells here. But the Marlbrook also contains more than just oysters, brachiopods, and snails. It has also yielded mosasaurs and even the occasional elasmosaur. There is even the possibility that a dinosaur was washed out to sea and could be found there. So if you collect in this area and find some bones, give me a call.
Many thanks to Trent Smith and the whole of Goza Middle School, not just for your hospitality, but for living the statement of Dr. Scott the Paleontologist on Dinosaur Train: “Get outside, get into nature, and make your own discoveries.”
“I have a dream…”
Almost everyone will have heard this most famous line by Martin Luther King, Jr. in the past few days. In honor of the holiday, rather than introduce another fossil, review a book, or some such thing, I thought I would do something a little different. I have a dream too, one in which teachers are not afraid to talk about evolution within the classroom, one in which people don’t recoil from the word because they think it goes against their religion, a dream in which everyone embraces the concepts, not because some scientist or teacher tells them they have to, not because they think it is part of a body of education they need to sound smart, but because they see the logic of evolutionary theory and the application of it in their everyday lives, because they understand how it affects them every day in ways they normally never even think about. In this essay, I am going to discuss a few of the many ways evolutionary theory helps us in practical applications. Next post I will discuss why I think most people deny evolution (it’s not what most people say, what people say and really think are often entirely different things), and why that denial is something we need to get past.
Cancer is an inescapable fact of life. All of us with either die from it or know someone who will. Cancer is so prevalent because it isn’t a disease in the way a flu or a cold is. No outside force or germ is needed to cause cancer (although it can). It arises from the very way we are put together. Most of the genes that are needed for multicellular life have been found to be associated with cancer. Cancer is a result of our natural genetic machinery that has been built up over billions of years breaking down over time.
Cancer is not only a result of evolutionary processes, cancer itself follows evolutionary theory as it grows. The immune system places a selective pressure on cancer cells, keeping it in check until the cancer evolves a way to avoid it and surpass it in a process known as immunoediting. Cancers face selective pressures in the microenvironments in which they grow. Due to the fast growth of cancer cells, they suck up oxygen in the tissues, causing wildly fluctuating oxygen levels as the body tries to get oxygen to the tissues. This sort of situation is bad for normal tissues and so it is for cancer, at least until they evolve and adapt. At some point, some cancer cells will develop the ability to use what is called aerobic glycolysis to make the ATP we use for energy. Ordinarily, our cells only use glycolysis when they run out of oxygen because aerobic respiration (aka oxidative phosphorylation) is far more efficient. Cancer cells, on the other hand, learn to use glycolysis all the time, even in the presence of abundant oxygen. They may not grow as quickly when there is plenty of oxygen, but they are far better than normal cells at hypoxic, or low oxygen, conditions, which they create by virtue of their metabolism. Moreover, they are better at taking up nutrients because many of the metabolic pathways for aerobic respiration also influence nutrient uptake, so shifting those pathways to nutrient uptake rather than metabolism ensures cancer cells get first pick of any nutrients in the area. The Warburg Effect, as this is called, works by selective pressures hindering those cells that can’t do so and favoring those that can. Because cancer cells have loose genetic controls and they are constantly dividing, the cancer population can evolve, whereas the normal cells cannot.
Evolutionary theory can also be used to track cancer as it metastasizes. If a person has several tumors, it is possible to take biopsies of each one and use standard cladistic programs that are normally used to determine evolutionary relationships between organisms to find which tumor is the original tumor. If the original tumor is not one of those biopsied, it will tell you where the cancer originated within the body. You can thus track the progression of cancer throughout a person’s body. Expanding on this, one can even track the effect of cancer through its effects on how organisms interact within ecosystems, creating its own evolutionary stamp on the environment as its effects radiate throughout the ecosystem.
I’ve talked about cancer at decent length (although I could easily go one for many more pages) because it is less well publicly known than some of the other ways that evolutionary theory helps us out in medicine. The increasing resistance of bacteria and viruses to antibiotics is well known. Antibiotic resistance follows standard evolutionary processes, with the result that antibiotic resistant bacteria are expected to kill 10 million people a year by 2050. People have to get a new flu shot every year because the flu viruses are legion and they evolve rapidly to bypass old vaccinations. If we are to accurately predict how the viruses may adapt and properly prepare vaccines for the coming year, evolutionary theory must be taken into account. Without it, the vaccines are much less likely to be effective. Evolutionary studies have pointed out important changes in the Ebola virus and how those changes are affecting its lethality, which will need to be taken into account for effective treatments. Tracking the origins of viruses, like the avian flu or swine flu, gives us information that will be useful in combating them or even stopping them at their source before they become a problem.
Another place that evolutionary theory comes into play is genetically modified organisms. I won’t get into the arguments about whether or not they are safe to eat, other than to say that there is very little evidence to indicate GMO food is any more dangerous than normal food (i.e., yes, there are certain dangers, but nothing that you won’t find in regular, non-GMO food). There are two things about GMOs that I do want to discuss here. First is the belief that GMOs are somehow altogether different from natural organisms. In truth, DNA is swapped between unrelated organisms all the time. Horizontal gene transfer, such as this DNA swapping is known, has been well known in bacteria for over a hundred years. In the past few decades, it has also been found throughout the plant kingdom and even (what people like to call) higher order animals. It has been estimated that as much as 8% of human DNA comes originally from viruses that made their way into our cells, some of which allowed the evolution of the placenta. We even have bacterial DNA in us.
GMOs also may have an effect on natural ecosystems. They can and do occasionally escape into the wild. Genes from the GMO oilseed rape plant that provide herbicide resistance has spread into wild mustard plants. These plants have spread quite far. Herbicide resistant weeds are springing up all over the world, to the detriment of our farmers and food supply. What was once only a concern for agriculturists is now a concern for anyone concerned about conservation of natural ecosystems. How much of an effect? Unless you understand how evolutionary changes can spread through an ecosystem and what ramifications that may have, you are simply guessing, which is of no use to anyone. People often think of this as a genetics problem or an ecology problem, but this is the effects of evolution at the ecosystem level.
The problems we see in GMOs are not really related to the fact that they are GMO, as evidenced by the natural horizontal gene transfer we see. We see similar problems with no GMOs involved. Pests becoming resistant to pesticides after generations (of the pest) of exposure is a common issue farmers need to address. Weeds will become resistant to herbicides on their own, with no help from GMOs needed. Evolutionary theory will help deal with this problem, guiding us to solutions we may never have reached otherwise.
Another highly controversial topic these days is climate change. Whether we caused it or not is really beside the point and is not a topic we will discuss here. It is undeniable by a quick glance at the evidence that the earth is getting warmer. We will have to deal with it, and so will every other living thing on the planet. Organisms respond to climate change in one of three ways: adapt, move, or die. There are numerous accounts of animals and plants shifting ranges in response to climate change. This is most easily seen in highly mobile organisms. Plants are not generally considered mobile, but pollen and many seeds have huge dispersal potential, so some plants can spread surprisingly quickly. The difference in dispersal ability is a big factor in how the plant communities adapt to climate change. This is not biological evolution in the strict sense of the word. However, over time, these shifts will cause evolutionary change as the population spatial patterns are disrupted.
Unfortunately for many animals and plants, humans have so sliced up the land that mobility is limited (for others, it is greatly expanded, but that is chiefly for things we don’t want to expand, like fire ants or zebra mussels and numerous other invasive species). For these organisms, they have the options of adapt or die. Obviously, this isn’t a conscious choice they make, but conscious or not, these are the options available to them. For these, if we want to know how they will respond to climate change, we need to know their evolutionary potential, what is their ability to adapt and how fast can they adapt. This will depend (assuming similar selective pressures based on climate change) in large part on the genetic variation within the species, their generation rate (the shorter the time between birth and reproduction, the faster evolution can function), and population size. As a result, their conservation depends on our understanding of their evolutionary potential.
A critical component here is time. It can be hard to tell whether or not evolution is occurring or more simple phenotypic plasticity (the ability of an organism to respond to changes via changes in gene expression rather than actual genetic change) without substantial genetic study. If an organism has a high phenotypic plasticity, they will be able to adapt quickly. However, if it requires real evolution in the strict sense, that takes time, meaning they will be less likely to adapt in time to prevent extinction. Again, this is a question that can only be answered by proper application of evolutionary principles.
These are just a few examples of how scientists are using evolutionary theory to save lives by improving medical treatments and protect our food supply and environment. I did not provide much in the way of specific examples of these processes, as that would expand this essay far beyond comfortable reading times. However, the links throughout the essay will lead to you several specific examples. Some people may argue that these examples are all microevolution and adaptation, not true macroevolution. In truth, there is no significant difference between the two. Microevolution and adaptation are simply subsets of a larger concept, processes that cause macroevolution over longer time frames.
More importantly, the argument doesn’t matter anyway. It is not important that doctors and farmers know the evolutionary history of earth. The application of evolutionary theory is the same whether one is looking at the present or eons in the past. One can incorporate evolutionary thinking and utilize the theory without ever having to deal with things that are millions of years old, but only if one understands the theory in the first place. Evolutionary theory touches on so many aspects of our lives that if we want to be able to make good decisions on many of the most pressing issues of our time, we need to have some basic understanding of how evolution works. If we do not teach evolutionary theory to our kids, we are crippling our future doctors, farmers, conservationists, fish and game managers, coastal development planners, lawmakers,…
Adam Savage and Jamie Hyneman of the Mythbusters do a great job of presenting commonly held myths and testing them in a variety of ways, trying and adjusting and retrying experiments. They even sometimes revisit myths with a new point of view and new questions. It is this that I think is the key to their success. They present science as a series of questions and experiments, revising and retesting, a dynamic process. Starting with what people believe and then presenting the evidence to show the real answer is an important part of the educational process. Derek Muller, who runs the Veritasium Youtube channel, did his PhD dissertation on just this topic, showing that simply providing the information did not increase learning. Unless the misconceptions the audience already held were first acknowledged and dealt with, people thought the material was clear and that they understood it, when in fact they had learned nothing at all.
All of this involves asking lots of questions. But what some teachers view as a downside to this approach (although it absolutely is not) is that invariably you will wind up with lots of questions you can’t answer. Your students will ask questions you have no idea what the answer might be. So what do you do in this case?
Hopefully, you already knew which of these options is the better choice. But where do you go to learn more? Some questions can be rather esoteric or have answers that can’t be easily looked up. Fortunately, hordes of scientists are at your beck and call to save the day. Here are four websites where you can ask real scientists any question you like. None of the scientists on these sites will do people’s homework for them, but are enthusiastic about answering questions.
Ask a Scientist has 30 scientists that will answer questions on biology, chemistry, physics, space, earth and environment, health, technology, and science careers. In addition, they have links to videos for some questions. You can look at answers to past questions and ask your own. Even though it is based in the United Kingdom, with all the scientists being from the U.K., they will answer questions from anyone.
This site is also based in the United Kingdom, but has scientists from all over the world. This site is limited to biology and paleontology, but it has over 100 scientists who can answer questions. Some are doctoral students, some are the tops in their field with decades of experience. All of them are experts in what they do and all of them are there to help. They have answered thousands of questions, all of which can be searched and read. If you don’t find what you are looking for, ask your own question. You might even find that you have started a lengthy discussion of your question between several experts, as has happened from time to time.
This Ask A Biologist is a National Science Foundation grantee and is hosted by Arizona State University. Again, it is limited to biology and is run by the biology faculty and graduate students of ASU. So on the one hand, you might think they might be more limited. But ASU has an extensive biology department and this site has much more ancillary material than most of the others. They have activities, stories,coloring pages, tons of images, videos, and links to other information. They have a teacher’s toolbox, providing easy searches for teachers to find exactly what they want, searchable by topic, activity, and grade level. In short, while they have several scientists available to answer questions, that is but one aspect of this educational site.
The Mad Sci Network has a huge amount of information. You can ask a question about anything. The site has experts from world class institutions available to answer questions. They have a searchable archive of over 36,000 questions already answered, so they may have already answered your question. In addition to the search features, they have several categories listed, in which you can pull up all the questions in those categories. They have a “Random Knowledge Generator” if you just want to have fun browsing at random. They also have a series of what they call “Mad Labs”, which are activities and experiments you can do at home or in the classroom. They have links to more information and resources elsewhere, including general science, educational methods and techniques, museums, science fairs, suppliers, and more.
So there you have it. When you are faced with questions you can’t answer, don’t try to bluff your way through. Who ya gonna call? Hundreds of scientists from around the world, that’s who.
All of the mistakes discussed so far are universal among humans to a greater or lesser degree. These last two are also universal and extremely common, leading to a world filled with pain and suffering, bigotry, and misunderstandings on a grand scale. I should warn you that this discussion will make many people uncomfortable because it cuts into the core of how people view themselves. People define themselves through the memories of their experiences and we tend to remember sound bites better than the complexities of reality, which makes for a dangerous combination.
5. We tend to oversimplify our thinking.
Of all of the mistakes, this one has most likely caused the most problems. When we were still living as hunter-gatherers in small bands, this was a benefit and can still be in some areas. When you live in an environment filled with potentially life-ending threats, you need to be able to recognize and react to them quickly. When that rustle in the bush may be a Smilodon about to attack, you can’t afford to think about all the different options because if you do, you are dead. But most of us no longer live in that sort of environment. We can take the time to think. We just have to fight our natural instincts that are hardwired into our brains. It’s tough, I realize that. It’s impossible to do all the time. But I hope you will see why it is so important that we try.
It is at the core of stereotypes and the “us vs. them” mentality that drives everyone to some extent. Any time you hear someone say, “Blacks are…,” or “Muslims are…,” or insert any group you want, that person is oversimplifying their thinking. It does not matter what you say after that first phrase, it will not accurately describe all members of that group. All “Blacks” are not actually black, nor do they share the same heritage, culture, language, or anything else. All those people that are thought of as Muslims by those using that stereotype are not in fact Muslim. I say this because almost invariably when non-Muslims refer to Muslims in a stereotypic fashion, they are confusing Arab (or anyone from the Middle East) and Muslim. Muslims and Arabs, like any large group, do not all share the same beliefs and culture.
In the first post in this series, I mentioned the anti-vaccine movement. It all started from ONE paper (since thoroughly discredited and debunked) that only referred to ONE specific vaccine. The whole point of the paper was to discredit that specific vaccine so the author could sell his own version. But no one in the anti-vaccine seems to remember that and they have simplified the topic to ALL vaccines.
In science, this sort of thinking causes people to read a single set of experiments (or even one experiment) on a specific target and then try to apply the result to everyone. This mistake is rampant in the medical field. A study will be published saying that a series of rats showed a result and instantly the media says that all humans will have the same result. Fortunately, scientists are well aware of the differences between rodents and humans. A result in rats and mice often does not carry over into humans. This is why all drugs have to go through human trials after they pass animal trials.
Even if a drug works in the small sample of humans, that sample is not truly representative of all humans. You may have heard that science has proven that vitamins are pointless and may even be harmful? The studies that indicated vitamins had no benefit were all done on healthy volunteers that mostly had good diets. So yes, if you are healthy and are getting everything you need from your diet, you don’t need vitamins and the excess can actually hurt you. Unfortunately, most people do not fall into this category, so for them, taking vitamins can indeed help. (This is just another example that eating right and having a healthy lifestyle will avoid many of the health problems most people have and will save you money in the long run. Exercise is almost always preferable to pills and is free.) Even healthy humans are incredibly variable and have different metabolisms. The same drug will not work the same on everyone.
All those internet memes you get with a picture of someone with a saying on it? Fabulous examples of oversimplification. The internet is full of examples of overly quick and thoughtless thinking. Here is a tip, if anyone can boil down the essence of a social problem with one pithy statement, it is almost guaranteed to be WRONG. I have heard more than one person say that because Muslims flew planes into the World Trade Centers, all Muslims were evil and should therefore all be killed, because “they all want to kill us anyway.” To any rational person, this statement is clearly, insanely, wrong. You may wonder why I have mentioned Muslims a few times. That is because right now, it is the most prevalent and dangerous stereotype I know and one which is very familiar to everyone. They either hold that view or know many who do.
I could go on and on about how people oversimplify for the rest of my life, but it gets seriously depressing rather quickly, so I will stop here. But I hope you get the point: Oversimplification, overgeneralizing, has led to the wrongful deaths of hundreds of millions of people and is the source of much of the hatred in the world. Be aware of just how common this mistake is and STOP DOING IT.
You how do you avoid this problem? Never take one study or one source as truth. It is ok to keep an open mind about something, but don’t put your faith into it unless you can verify it through other reliable sources. Wait for other studies that confirm the results because it may be that the first study was wrong. Avoid overgeneralizing. Just because something worked once, do not think it will work every time. Always, always, always keep the parameters of a study in mind, respect the limitations of any study. A result on one mouse in one situation has little to do with results from many people in all sorts of variable conditions. Do not extrapolate beyond the data without clearly understanding that the extrapolation is purely speculative guesswork and may not hold up in reality.
6. We have faulty memories.
One way that our memories are faulty is in that confirmatory bias discussed in the previous post. You can see this problem in everyone who gambles, be it at a casino or the stock market. Most people remember their successes far more commonly than their losses. People can lose fortunes this way. Casinos are masters at exploiting this mistake. If a gambler wins early, they tend to continue playing long after they have lost their winnings and more. Every time they win, they remember that one win and forget all the loses before that. Some people do the opposite, focusing on their failures and minimizing their successes, which leads to problems therapists deal with every day.
Science, particularly medical science, has a form of institutionalized faulty memory. It is much easier to publish positive results than negative ones. Therefore, experiments that didn’t work tend to be glossed over and forgotten, focusing on the ones that succeed. Of course, if those successes are due to chance or faulty experimental design, ignoring the negative results leads the whole field astray. How serious is the problem? A paper in 2012 found that only 6 out of 53 “landmark” papers in haemotology (study of blood) and oncology (cancer research) could be replicated. This sort of publication bias on the positive can have profound problems. It may sound like this means that science can’t be trusted, but what it really means is that it is critically important to never jump on the bandwagon and follow the advice of a new study. Wait until it can be confirmed by other research. Science is all about throwing hypotheses out there and testing them to see if they really work. One test doesn’t do it. Multiple tests are needed and you cannot forget the failures.
Where faulty memory really comes into play is in just how easy it is to change our memories. Simply hearing another person’s experiences can change our own. My favorite study showing this interviewed people about their experiences at Disney World. The participants watched an ad showing people interacting with Bugs Bunny at Disney World. The fact that this event is impossible (Bugs Bunny was not owned by Disney and so could not make an appearance at Disney World) did not keep many of the people from saying that they had fond memories of seeing Bugs Bunny at Disney World.
Kida discusses the results from some researchers in which they asked students where they were when they first heard of the space shuttle Challenger exploding. They asked shortly after the event and then again two and a half years later. Despite claiming that their memories were accurate, none of them were entirely accurate. Some of them were wildly off. Yet the students insisted that they were correct and disavowed the record of their earlier remembrance. There are several studies like this that say the same thing: our brains do not faithfully record our experiences and those memories change both over time and through suggestion by others.
So, what does this mean for us? It means that we have a bad habit of misattributing things, combining memories or making them up whole cloth. Criminal psychologists are deeply aware that eyewitness testimony is the least reliable evidence that can be brought into court, despite the fact that it is considered the most reliable by most people. People commonly say “I’ll believe it when I see it,” and “I saw it happen with my own two eyes!” We put a lot of stock into our perceptions and our memories. But, as is quite clear from decades of research, neither our perceptions or our memories are at all reliable.
So what are we to do if we can’t rely on our own experiences? Make records, take pictures, write it down. Compare experiences with other people. There is some truth to the now common statement; “Pics or it didn’t happen.”
And so we conclude the introduction to the six basic errors in thinking we all make to a greater or lesser extent. These mistakes are universal, they happen repeatedly daily basis. Yet they have grave consequences. In science, we have ways to try to avoid them. We record data. We share it with others and let them try to poke holes in it. We do not trust only one example and demand verification. Scientists make these mistakes all the time. But by being aware of the mistakes and having procedures in place to deal with them, we can minimize the problems.
When I was a kid, I was always taught the scientific method is a matter of developing hypotheses, testing them, and using the observations from the tests to revise the hypotheses. Very straightforward, but overly simplistic. My teachers rarely, if ever, talked about the crucial strategy of multiple working hypotheses, coming up with every imaginable way that could explain our observations before we started trying to test them. But the most important thing that was never taught was how to think explicitly and clearly. Logical and clear thinking is the heart and soul of science. In fact, there is no decision that cannot be improved by clearly thinking about the question and the available data. We just celebrated Independence Day in the United States. It is time we celebrate our independence from fuzzy, ill-defined, and confused thinking. In the last post, I discussed the critical importance of clearly defining a problem in terms of actionable questions. The first step is to understand a problem well enough that it can be clearly articulated and defined. Then all factors that contribute to the problem can be clarified. But you can’t stop there. Once you have a list of known factors, you have to decide which ones you can actually do something about and not waste time arguing about those you can’t change. Focusing on the definable and workable factors produces results. Wasting time on things you can do nothing about is counterproductive. In this post, I am going to briefly discuss the first three of six general mistakes that EVERYONE makes from time to time. You can never be completely rid of them, but you can be aware of them and try to reduce their influence in your life. If you do this, I promise you will make better decisions. You will improve your life and the lives of those you touch. These six mistakes are outlined and fully discussed in the book Don’t Believe Everything You Think: The 6 Basic Mistakes We Make in Thinking, by Thomas Kida. I highly recommend you get this book and read it.
1. We prefer stories to statistics. People are terrible at statistics, even people who really should know better, so bad in fact, that they make them up to sound smart. You can easily find numerous variations of the statement, “80% of all statistics are made up on the spot, including this one.” Or, as often (likely incorrectly) attributed to Mark Twain, “there are three kinds of lies: lies, damn lies, and statistics.” So it’s no wonder that people suck at them and prefer stories. There are abundant studies illustrating how our brains are wired to listen to stories, how personal stories influence our behavior more than statistics, such as this one, or this one. Statistics happen to abstract groups, stories happen to identifiable people. We even prefer to dress up our information to make it more personal, more interesting, but the very act of storifying information makes that information less likely to be true. It is much more likely that Bill robbed Peter than it is that Bill robbed Peter AND paid Paul. The more complicated things get, the less likely. But this mental shortcut can cause serious problems. This is well illustrated by the anti-vaccination scaremongering going about. The whole anti-vax movement can really be traced to one report by Dr. Andrew Wakefield in 1998 that found a correlation between vaccines and autism, research that has been completely discredited and proven fraudulent. Since then numerous studies have linked into the alleged link and found nothing, such as this one. But no matter how many studies find no link, many people hear Jenny McCarthy talk about her autistic son, they hear others talk about their autistic children, and come to the conclusion that all the studies must be wrong, because the stories carry more weight with them. Disregarding the millions of children who get vaccines that never develop autism, people focus only on the stories of people that claim otherwise. Thus, thousands of children are getting sick and dying because of a belief in stories over statistics.
2. We seek to confirm, not to question. Have you ever read something that you disagreed with and instantly dismissed it or conversely, have you ever accepted evidence simply because it agreed with what you thought? If so (and you have, everyone does), you are guilty of confirmation bias. Confirmation bias causes people to seek out and weigh information that already agrees with their point of view and disregard evidence that disagrees with them without ever really analyzing the data. If you get all your news from either FOXNews or MSNBC, you are likely to rarely, if ever, hear contrary points of view and are thereby limiting input to only that which you already agree. Thus, people who do so will weigh that evidence in favor of their preconceptions and will assume that their view is more prevalent than it really is. If one gets all their information about evolution from the Institute for Creation Research, they will never get accurate information about the theory as the ICR is based on the belief that evolution is false, so they seek only information that discounts it. The only way to avoid this is to seek out diverse news outlets. While you read them, remind yourself that you will suffer from confirmation bias, so you may (hopefully) be able to give evidence from all sides a thorough critique.
Lest you think that only untrained laymen fall into this trap, confirmatory bias is rampant in science as well and it is a serious problem. Even the ivied halls of Harvard do not protect one from poor thinking and confirmatory bias as this article by Neuroskeptic clearly illustrates wherein he takes a fellow neuroscientist to task for not recognizing the fallacy of only looking for confirmatory results. There is a publication bias in the scientific literature towards positive results, the negative results get mentioned much less often. While this is true in all fields, it is particularly important in medical research, and psychology research has been hit particularly hard lately.
Next post, I will cover the next two common mistakes. Stay tuned.
If ink was blood, the discussion of the lack of women in STEM fields would exsanguinate the whole of the human species. Yet for all the talk, the problem remains. Why? Let me answer that by bringing to your attention a post by Dr. Janet Stemwedel, a professor of philosophy at San José State University who writes on this and other topics concerning the thinking underlying how science is done. The post is not long, so I will post most of it here, you may find the original here. To clarify the post in case it doesn’t come across clearly: she quotes a block of text discussing the gender gap in the sciences and then provides her response to it.
However, there are times when people seem to lose the thread when they spin their causal stories. For example:
“The point of focusing on innate psychological differences is not to draw attention away from anti-female discrimination. The research clearly shows that such discrimination exists—among other things, women seem to be paid less for equal work. Nor does it imply that the sexes have nothing in common. Quite frankly, the opposite is true. Nor does it imply that women—or men—are blameworthy for their attributes.
Rather, the point is that anti-female discrimination isn’t the only cause of the gender gap. As we learn more about sex differences, we’ve built better theories to explain the non-identical distribution of the sexes among the sciences. Science is always tentative, but the latest research suggests that discrimination has a weaker impact than people might think, and that innate sex differences explain quite a lot.”
What I’m seeing here is a claim that amounts to “there would still be a gender gap in the sciences even if we eliminated anti-female discrimination” — in other words, that the causal powers of innate sex differences would be enough to create a gender gap.
To this claim, I would like to suggest:
1. that there is absolutely no reason not to work to eliminate anti-female discrimination; whether or not there are other causes that are harder to change, such discrimination seems like something we can change, and it has negative effects on those subject to it;
2. that is is an empirical question whether, in the absence of anti-female discrimination, there would still be a gender gap in the sciences; given the complexity of humans and their social structures, controlled studies in psychology are models of real life that abstract away lots of details*, and when the rubber hits the road in the real phenomena we are modeling, things may play out differently.
Let’s settle the question of how much anti-female discrimination matters by getting rid of it.
Dr. Stemwedel hits directly on a error that is seen throughout every facet of social interactions, to say nothing of public understanding of science. The discussion had strayed into unproductive areas and away from any attempt to resolve the problem. Dr. Stemwedel attempted to bring the focus back to the problem needing to be solved.
In this instance, going back to the original post to which Dr. Stemwedel was responding, the initial question put to Neil DeGrasse Tyson was “Why are there fewer women in science?” The true answer to that question is that there are multiple reasons for the gender gap, one of which happens to be that there is a clear discriminatory bias against women in science (this fact is so well documented that linking to only one or two articles seems pointless as a quick Google search will immediately turn up a very long list of sources). Tyson did not deny there were other factors, but he focused on the sociological aspect as that problem is highly prevalent and something that can be changed.
Chris Martin, the author of the post Dr. Stemwedel was responding to, goes to great lengths to talk about all the other issues involved in the gender gap, ignoring the reason Tyson focused on the sociologic aspect. Contrary to the claims of Mr. Martin, the point was indeed to draw attention away from anti-female discrimination. He clearly states in his post that he believes evolutionary pressures explain the gender gap better than sociological ones and that the sociological factors are therefore unimportant. His whole post is a response to the assertion that this bias prevents many women from entering the field.
Unfortunately for Mr. Martin, the evolutionary factors Mr. Martin espoused are not as well understood and nowhere near as well documented in humans as is the discrimination against women. But here is the important thing: We can’t do anything about past evolutionary pressures. We CAN do something about the discrimination. No one is arguing there aren’t other reasons. But if you want to solve the problem, you focus on the aspects of the problem you can fix.
This problem in thinking is so widespread, one could easily argue that everyone does it. Certainly, unless taught to do otherwise, everyone does indeed make this mistake. In all of science and engineering, there is one basic rule that is critically important you must do: clearly define the problem in terms that can be dealt with. You have to be able to understand the problem in clear enough terms that you can parse out what things are relevant from those that are not. In this case, claiming there are evolutionary pressures is irrelevant to the problem of reducing the gender gap. We know that anti-female discrimination occurs. We know it is widespread. Of all the problems that Mr. Martin mentioned, this is the one that most obviously lends itself to resolution because it involves behaviors that the vast majority of people can agree on that needs to end. Unless one can reasonably expect to fix evolutionary pressures, distracting attention from the problem that can be solved is counterproductive. The good news is that when people do focus on the problems, things can and have gotten better. We still have a long ways to go, but it is improving.
The point of this post is not really to argue about anti-female discrimination in science, although that is a hugely important topic and something that every teacher needs to be aware of and help to stop. The real point of this post is to highlight the importance of knowing your question well enough and clearly enough that you can make progress on answering it, solving the problem. This particular topic just happens to allow me to highlight two really important topics at the same time. The next post will cover some more vitally important mistakes in thinking that anyone trying to teach the nature of science, and really, any other subject, needs to understand so you can work hard on helping your students overcome them.