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Website Review and the Misconception of a Theory

In a quick review, I would like to discuss the website by Lin and Don Donn, http://earlyhumans.mrdonn.org/evolution.html.

This website is part of a much larger website that is filled with a lot of information on all sorts of history. As Mr. Donn states, they do not claim to be experts in anything, so do not claim everything on the site is correct, although they do try. It is clear they have put a great deal of time and effort into making a substantial site with the honest intention of providing accurate and useful information to teachers. They have won awards for an impressive site. However, in the evolution of humans, they seriously fall down.

The early humans website has several links to good resources. Unfortunately, it has two things that destroy the science educational credibility of the site completely. The first is a link to a presentation teaching Biblical creationism, a subject that has no place in a public school as it is both scientifically invalid and pushes one specific religious view, which is illegal in the United States. Regardless of whether one believes in creationism or not, it is not legal to teach a specific religion in public schools and it is especially not valid to teach that religious view in a science class. The only way to make this legal would be to teach the creationism stories of every other religion equally, without comment as to which one the teacher believed, which would be impossible. Even then, it would have to be in a religious studies class, not a science class. If we are to preserve everyone’s First Amendment rights to freedom of religion, we simply cannot have government-run public schools teach one religious view and we certainly cannot teach that view as a scientifically valid theory. I am hitting this point especially hard because it is a serious point of controversy in the United States, but it should not be. Keeping creationism out of the schools is not an attempt to suppress anyone’s views. It is an attempt to preserve everyone’s right to make their own religious choices without government interference.

That leads me into the second problem, one which is stated boldly right up front. One of the big problems we have in science literacy is that many people do not understand the difference between the colloquial use of the term “theory” and the scientific meaning of the term. To quote the website: “A theory is a guess based on some facts.  Remember a theory is not proven.  One of the great controversies of our time has been the theory of evolution.” This is massively wrong in two areas.

The term they have defined is NOT a theory. What they defined was SPECULATION. Anyone can come up with an idea, but that does not make it a scientific theory. First, one must have a hypothesis, which is a testable idea, based on observation, that explains a relationship between two or more measurable things. There are two critical parts to this. The observations, so it must be an attempt to explain something we actually see in the real world. Second, that explanation must be testable. If there is no conceivable way to test it, the idea remains in the realm of speculation and can never be taken as a scientific theory, or even a valid hypothesis.


Great hypothesis, but not the way to do science.

Once one has a series of hypotheses that have been tested by many people, none of whom have been able to disprove the hypotheses, one can formulate a scientific theory. That theory ties the hypotheses together, explaining numerous detailed observations into an explanatory framework that applies broadly. An example of this is the Theory of Gravity. Numerous observations were made showing gravity exists, there is no doubt about that. Many observations showed precisely how it worked and the relationship of different masses to each other, both on earth and in the universe as a whole. However, to make a theory, we needed more than these observations, we needed a way to accurately describe and predict these relationships. Isaac Newton discovered a mathematical equation that could be used to predict the motions of the planets. That equation was then tested many times and found to be valid everywhere, at least at the speeds attained by most things in the universe. Einstein went further with his Theory of Relativity, which extended our understanding of gravity into realms beyond the experience of everyday existence. Even here, these started out as hypotheses, requiring many people to test over and over gain. Not only has no one been able to prove them wrong, but no one has come up with an explanation that better fits the data. Therein lies the key, testing and testing and basing the acceptance of the theory on data, evidence that either supports or disproves the theory. Without that, it is not a theory.


As such, there is no Law of Gravity. We know it exists, it is fact that is undeniable. The Theory of Gravity provides a framework in which gravity works that has been put to the test. In a similar fashion, there is no Law of Evolution. We know it exists, it is a fact that is undeniable. Why? Because the idea that biological life forms change over time is something that cannot be argued against. All one has to do is acknowledge we are not clones of our parents, or look at the diversity of changes brought about by dog and cat breeders, sheep and cow breeders. We see biological change all around us. Evolution is therefore a fact, just like gravity. The Theory of Evolution put forth by Darwin is more properly called the Theory of Natural Selection, which explained this change through the aforementioned natural selection. It has been tested numerous times and shown to work. Is natural selection the only way in which species change? No, but it is a major mechanism. But the point here is that it has been tested and retested. Like all scientific theories, it is not simply a guess based on a few facts. It is permissible to argue about specific mechanisms, but trying to argue whether or not evolution occurs is like arguing whether or not the earth is flat or that we need air to survive.

Evolution and Gravity are Theories (Humor)

Dino Sites to Avoid

I have been working on lectures on early amniote evolution, along with the following reptilomorph and synapsid lectures for my vertebrate paleontology course. We will be getting into dinosaurs and the other Mesozoic animals very soon, hooray! However, in preparing these talks, it has brought to my attention just how prevalent two sites in particular are: Reptileevolution.com and Pteresaurheresies.wordpress.com.


When I did a search for “pterosaur”, Google actually responded by saying “Did you mean pterosaur heresies” and provided images that all but one are either from the site or sites complaining about the site.

This is quite unfortunate. Both sites present an abundance of beautiful artwork done by a stellar paleoartist. There is an abundance of information on the animals and their relationships. All in all, the websites look fantastic and are quite the draw for paleo-enthusiasts.

But it is all wrong.

None of the hypotheses presented on these pages is accepted by virtually any other paleontologist. The techniques used to gather the information is not considered valid and no one who has tried to reproduce the data using the methods have had any success.

I won’t get into details about why the websites are wrong. I am frankly not qualified enough to provide a step-by-step breakdown of the problems (not being an expert in either pterosaurs or basal tetrapods), nor do I really have the time. I will say that many years ago, I heard the author of these websites give a talk about his evidence for a vampiric pterosaur and even as a young undergraduate, it was clear to me that neither the technique nor the conclusions were valid. I found it very unfortunate because the idea of a vampiric pterosaur was incredibly cool and the technique, which involves detailed image study, is useful in many contexts. However, it is very easy to let personal biases enter into conclusion based on these methods, to allow oneself to extrapolate well beyond anything the data can actually support. Oftentimes, those biases are completely unknown to the observer simply due to the way our brains interpret sensory input and modifies them based on past experience. We really do not see everything we think we see, which is why the scientific method requires other scientists examining your conclusions and your methods and trying to poke holes in your ideas. So it is vital to recheck one’s conclusions with many detailed images from various angles and lighting methods and, most importantly, detailed examination of the fossil itself.

So instead, I will point you to articles written by people who are experts in the very animals that are discussed on those pages and what they have to say about them. The first is an article by Dr. Christopher Bennett, who is an expert on pterosaurs. In this article, he discusses the validity of the techniques and discusses specific claims of two pterosaurs in particular, Anurognathus and Pterodactylus. Anurognathus is a very odd-looking pterosaur and is quite aptly named “frog mouth.” Pterodactylus is probably the most famous pterosaur next to Pteranodon and is why so many people mistakenly refer to all pterosaurs as pterodactyls.  Dr. Bennett does an excellent job critiquing the science in a professional and readable way.

Dr. Bennett's article.

Dr. Bennett’s article.

The second article is a blog post by Darren Naish, a noted researcher and science author that has researched pterosaurs and many other animals who has a deep understanding of both the accepted science and the author of these websites and the work presented therein. Here is what he says: “ReptileEvolution.com does not represent a trustworthy source that people should consult or rely on.Students, amateur researchers and the lay public should be strongly advised to avoid or ignore it.” The emphasis is completely his. The post is quite long and discusses several aspects of the work, discussing the accepted science and the material on the websites that is not accurate, including the techniques used to arrive at the conclusions, both accepted techniques and those by the website author that are not.

The next site is an article by Pterosaur.net, a website devoted to research on pterosaurs by pterosaur researchers. It is a brief article that uses Naish’s article as a starting point and continues on with a discussion of why they think it important for people to know why these sites should be avoided. To quote: “The issue taken with ReptileEvolution.com is not that it exists, but that it’s internet presence has grown to the point that it is now a top-listed site for many palaeo-based searches. Tap virtually any Mesozoic reptile species into Google and either ReptileEvolution.com or the Pterosaur Heresies is likely to be in the first few hits. The situation is even worse for image searches, which are increasingly dominated by the many graphics that Peters’ uses on his sites.” This would not be a problem that the sites are so well known if they were correct, but their prevalence presents a highly flawed version of what scientists really think. People are taking these sites as truth, when in fact they are regarded by professionals as seriously wrong.

Finally, Brian Switek, a science writer who authors the blog Laelaps, which moved from Wired Science Blogs to National Geographic and the now-defunct blog Dinosaur Tracking for the Smithsonian,  wrote a piece on the site, in which he urged more paleontologists and paleontology blogs to call out misleading websites like these.  In that spirit, I hope I can help some avoid getting a mistaken impression of dinosaur science and help steer them to better, more reliable sources.

* If you are wondering why I say “the author” or “the artist” rather than using the person’s name, it is because I don’t want this to be about the person, but the information. I don’t personally know the author, nor have I ever had direct contact, so I have nothing to say about the person. The work, however, can be and should be open for criticism, just like any other researcher, including my own.

Life is one big family

tolTeaching how all life is interrelated is a whole lot easier if you can show something akin to a family tree for living organisms. The Paleobiology Database has all the fossils organized by taxonomic  relationships to help you find things in the database, but it is not very useful for visualizations. The Encyclopedia of Life has lot of information and multimedia available for over a million individual species and shows how they are classified and is quite useful if one is looking for information on a particular species. But again, it is not very visual.

The Tree of Life website is an excellent website providing a great deal of information on phylogenetic relationships (for good discussion of phylogenetics, try here and here), providing abundant references on the primary literature discussing how scientists think various organisms are related. They work in collaboration with the Encyclopedia of Life, with the EOL focusing on species pages and TOL focusing on relationships. On TOL, one can start at the base of the tree and click on various branches following different groups into smaller and smaller groups, with each page providing what groups are descended from the starting group. For instance, the base of the tree starts with links to eubacteria, eukaryotes, and archaea, with viruses with a question mark. Each one is hyperlinked to a page discussing relationships within that group. It also provides a discussion of possible alternative branchings as well. Thus, the relationships are not presented as “we know this to be true,” but as an active, ongoing process of discovery and research. It is often highly technical, but would be extremely useful for high school students working on an evolutionary or biodiversity topic.


The Tree of Life and the Encyclopedia of Life are great sources for information on species and their phylogenetic relationships, but if you want better visualizations of the sum total of biodiversity, there are other websites that are definitely worth your time.

The first I would like to mention is the Tree of Life interactive by the Wellcome Trust and BBC. Watch the great video with David Attenborough first, then dive into the tree itself. The tree simplifies life to about 100 representative species. It is seriously weighted toward mammals, so provides a very skewed version of biodiversity, but the presentation should appeal to those who are most interested in the overall development from bacteria to humans. If once clicks on any individual species, it highlights the path to the base of the tree and provides a text description and in some cases pictures, a video, and locations. Click on another species and the path to the last common ancestor of the two selected species is highlighted. All the files are open source and available for free download, including the images and videos.


timetree_poster_finalAnother interesting site is the Time Tree. This site has a poster that shows 1610 families of organisms available for free download. The poster does a better job of showing the true diversity, but is still heavily weighted towards eukaryotes. However, the real purpose of the site is to provide divergence dates between two species. Simply type in two species names using either scientific (say, Homo sapiens and Gallus gallus) or common name (say, human and chicken) and it will provide how long ago their last common ancestor lived. It should be noted here that the dates listed are estimates based on molecular data. They should not be considered as conclusive dates or anywhere near as precise as listed. Indeed, the value given is a mean value of several estimates, with the median value also given, as well as what they call an “expert result” (which they sadly do not explain). In addition, they provide the scientific references the results came from and the dates provided for each, which can be quite broad. In the example above, those values range from 196.5 to 328.4 million years ago, but of the nine studies listed, all but two fall within 317.9 and 328.4 million years ago. There is also a mobile version of the site, as well as an iPhone/iPad app, as well as a book.

Another site of interest is Evogeneao.com.  They have an interesting Great Tree of Life, as they call it, which like most others is heavily weighted toward eukaryotes. They have good explanations of evolution, along with a set of resources for teachers, including an interesting suggestion for how to introduce evolution to students. The interesting part of this site is their discussion of evolutionary genealogy, in which they extend the idea of a family tree farther back than it typically seen. They provide methods to calculate how far removed you are from other species. You can pick from a list of animals and it will tell you how closely you are related. For instance, choosing dolphin returns an estimate of 27 millionth cousin, 9 million times removed. That nicely encapsulates not only the idea of relatedness, but the immense scales of time we are talking about.


itolThe Interactive Tree of Life, or iTOL, is another interesting site that may be of interest to high school teachers. This site utilizes genomic data as the basis of its trees and, unlike the others, provides a better visual indicating how truly diverse prokaryotes are in relation to us.  It also allows you to print out phylogenetic trees in different formats, depending on your preferences and what sort of information you want to display. You can even upload your own data if you wish, but most teachers will likely choose to stick with the displays already provided, as there are simpler programs to deal with trees that any but the most precocious senior high school student (or college student for that matter) may wish to create.

There are a few other interactive trees out there that may be more appropriate to younger viewers. One is at the London Natural History Museum website. This one is very simplistic, having only sixteen branches, with four of them being primates, but it gets the point across. This interactive is limited to providing the link between any two branches and the name of the group containing both. For instance, clicking on the banana and the butterfly gives the name Eukaryota.  Another site provides an interactive for the poster Charles Darwin’s Tree of Life. This interactive allows one to zoom in on any part of the tree and if one clicks on an animal, a short description of the animal is provided. Sadly, the two best interactives I have yet seen are not available on the internet. I had the opportunity to explore DeepTree at the Harvard Natural History Museum and it is truly spectacular, as is their FloTree. If you get a chance to see them, you should. Hopefully, one day they will be available in a broader format than now.

All of this assumes of course, that people actually know how to read these trees, which is a false assumption in that most people really do not. So it would be useful to spend some time getting familiar with proper interpretation of them before using them in class. There are several resources explaining this (such as here and a really excellent video here), so I will not put a tutorial on here unless there are requests to do so.

All images posted here are from the websites being discussed and are copyrighted to them.

You were here: Maps for seeing geography through time

It may seem that the earth is pretty stable. You can always count on the mountains being there when you look for them. But the Earth is a dynamic place. Volcanoes, floods, landslides, and earthquakes all change the landscape in ways we can see quickly.  What we don’t typically see is that if we expand these processes over long periods of time, those same processes alter the landscape far beyond our experiences. The surface of the Earth is covered in a crust broken up into numerous plates, which are constantly shifting and moving. The plates only move between 2.5 – 15 cm/year (the previous link contains information on how this is measured and provides activities for teachers for use in the classroom), but add this up over millions of years and the Earth looks quite different. Add into this mountain-building and erosion wearing down the mountains and you get radically different geographies for the planet.

094So what did the Earth look like in the past? There are two excellent sources providing maps of the planet through time. The first is the PALEOMAP Project, by Dr. Christopher Scotese. On this website, you will find maps ranging from 650 million years ago to the modern day and even into the future. There are 3D animated globes and interactive maps. He includes a methods section for how the maps wer put together and a list of references and publications. There is also a climate history section providing brief descriptions of the climate at various points in time. For teachers, there are several educational resources available, some of which are free, but others are available for a fee. There is even an app for the iPhone/iPad. It is not available yet for either android or Windows, but that has been admirably taken care of by the Howard Hughes Medical Institute with their Earthviewer app and they have done a wonderful job. the app is fully interactive, allowing easy scrolling through time and full rotation of the globe. You can also track atmospheric oxygen and carbon dioxide, day length, important fossils, biological and geological events, and major meteor impacts. The app even provides a bibliography of their source material. In addition to the maps from Dr. Scotese, the app extends the timeline back to 4.5 billion years (although this extension is obviously not nearly as detailed as the Scotese maps due to the greatly extended time and the greatly decreased amount of available data). All in all, a great app, also reviewed by the NSTA.


The second site that will be of interest is the Library of Paleogeography run by Dr. Ron Blakely. These maps cover approximately the same time frame as those provided by Dr. Scotese and are not animated. However, Dr. Blakely provides maps in different projections and provides regional coverage beyond that of global maps. So if you are specifically interested in paleogeographic maps of North America and Europe, this is an excellent resource.

A third site also provides paleogeographic maps which are very useful. In this case, the maps are secondary to the main purpose of mapping fossil locations. The Paleobiology Database contains records of fossil locations that have been published in  the primary literature. One can perform a search by organism or group, country, rock unit or type, time interval, paleoenvironment, or publication. The results from the search are mapped onto global maps based on the PALEMAP Project.

Dromeosaur fossils in 70 million year old rocks.

Dromeosaur fossils in 70 million year old rocks.

All of these sources are available to the public and are used by professional researchers. Therefore, one can safely assume they represent accurate assessments of current, generally accepted thoughts on our Earth through time. You may notice that maps from Scotese and Blakely may not completely agree on all aspects. This is because it is very hard to piece together all the evidence and trace the movements of the continents backwards through time. Often, the data is incomplete and they have to make judgment calls based on the available evidence. Not everyone makes the same choices. This is true even for maps of current geography and is even more so for paleogeography.  As we get more data and better techniques, those disagreements become fewer and fewer, but there is still much work to be done, so these maps can and will most likely be refined in the future to reflect new research.


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