Adventures in Geology: Darwin & Fossils

Last year was the anniversary of the birth of Charles Darwin, and the 150th anniversary of the publication of his book On the Origin of Species.  One of the activities I was involved in was work with a group of middle school students to explore some of the ideas shown in the Wordle that I designed used the nifty program at
Wordle: Darwin and Wallace

We had planned three activities to help the students see how fossils were important to Darwin, and to also show that Darwin used geology as as an important aspect in the future development of his theory to explain how species changed over time. Here are the activities we did.  Following the description of the activities is the slide show in YouTube form I used to help the students explore these ideas

Mystery at the Ringgold Road Cut. In this activity, the students were given a bag of crinoid stems that I had collected from lower Paleozoic rocks in Northwest Georgia (as shown in the photo here), a hand lens, and a metric rule.

Crinoid stems used in an activity with student in which they make observations and inferences about these "mystery" objects.
Sedimentary bed containing crinoid fossils in NW Georgia

They were asked to investigate the objects, and use observations of the fossils to pose questions, and make conclusions about what they thought the objects might be.

Being a Palentologist. Into brown paper bags, we put a fossil and a geological time scale that included drawings of organisms associated with the three geological eras. Students picked up a bag, and then proceeded to use their powers of observation to try and interpret when the fossil might have lived and in what kind of environment. When they had an idea, they could pick up a sheet of paper with further information about their fossil. Fossils included: brachiopod, oyster, petrified wood, shark tooth, amber, coprolite, fern, fossil fish, trilobite, sea urchin, dinosaur bone.

The Footprint Puzzle. We provided the students with a footprint showing two sets of fossil tracks (of dinosaurs). The students used the tracks to discuss what they thought might be going on. In the map of the tracks, the tracks converge and at the point of convergence, there tracks overlap each other. After some discussion, students make the inference that there were two dinosaurs, and they met up, and either mated, or had a fight. When then provided them one additional piece of information. The additional information showed only one set of tracks exiting the area of convergence.

In the movie that follows, we used images of Darwin’s voyage around the world, images from Down House, Darwin’s family, a picture and reading of the letter he received from Alfred Russel Wallace in 1858 that shocked Darwin into making his theory of natural selection public, and indeed, his and Wallace’s papers were read at the Linnean Society in London in 1858.  Enjoy!

What Would Darwin Say About Intelligent Design?

In this month’s Scientific American there is a very interesting article written by Glenn Branch & Eugenie C. Scott entitled The Latest Face of Creationism in the Classroom. There are three key ideas in the article, and they highlight the controversies that have surrounded the teaching of evolution in American public schools.  Here are the key ideas:

  • Creationists continue to agitate against the teaching of evolution in public schools, adapting their tactics to match the roadblocks they encounter.
  • Past strategies have included portraying creationism as a credible alternative to evolution and disguising it under the name “intelligent design.”
  • Other tactics misrepresent evolution as scientifically controversial and pretend that advocates for teaching creationism are defending academic freedom.
What would Darwin say?
We should start by saying that Charles Darwin would probably not be surprised by the controversy.  He held off publishing his theory of evolution, and only published it when he was shocked that Alfred Russell Wallace had independently arrived at the same theory explaining the descendence of new species.  He held off publishing knowing that his ideas would raise questions about human origins, and as a result he didn’t publish his book on human origins, The Descent of Man until 1871, 12 years after Origins was published.

Darwin's second book on evolution, The Descent of Man, was published in 1871.
Darwin's second book on evolution, The Descent of Man, was published in 1871.
However, let us be clear, that Darwin was very confident that he and Wallace has discovered how species evolve, one from another.  Here is what Darwin had to say about humans and evolutionary theory:
“Man at the present day is liable, like every other animal, to multiform individual differences or slight variations, so no doubt were the early progenitors of man; the variations being formerly induced by the same general causes, and governed by the same general and complex laws as at present.  As all animals tend to multiply beyond their means of subsistence, so it must have been with the progenitors of man; and this would inevitably lead to a struggle for existence and to natural selection.”
Darwin would probably denounce creationism and intelligent design as alternative explanations of how species have evolved on the Earth.  In fact, Darwin dealt with each of these ideas especially during the period of 1840s and 1850s when he was developing his ideas on evolution.  Although Darwin was not as religious as some might hope for, he had studied religion in undergraduate school, and his parents hoped he would enter the ministry.  His ideas on religion changed over time, the death by yellow fever of one his very young children led him to reject the religious beliefs that he had developed in the Anglican Church.  He and his wife were active in the Unitarian Church.  He would oppose creationism, not based on his religious views, but because of his understanding of the nature of science, and the fact that he had considered all of the objections to his theory that he knew the creationists would raise.  In his book, On the Origins of Species, he devotes several chapters to answer the fundamental questions that would be raised about the theory.  For example, Chapter 2 of Origins is entitled “Difficulties of the Theory,” in which he discusses why transitional fossils are so rare.  Chapters 7 – 10 continue his discussion of difficulties with the evidence, and helps the reader deal with the potential questions that will arise, and provides powerful answers.
As for his view of “intelligent design,” Darwin concluded that evolution proceeded by means of natural selection without a Divine Creator, or some other intelligent agent.  The chief proponent of intelligent at the time was William Paley (1743 – 1805).  Paley had used a teleological argument using the watchmaker analogy to argue that the inner workings of a watch need an intelligent designer, and as with the watch, the complexity of some part or aspect of nature (like a complex organ, or organism) would necessitate a designer.  Darwin, during his early years, accepted, like many others, Paley’s argument of intelligent design.  Darwin, as he thought about, and as he developed his theory of the origin of the species by means of natural selection, not only challenged Paley’s idea of an intelligent designer, but saw that his and Wallace’s theory was the scientific evidence to reject intelligent design.  To Darwin, it was the diversity in nature that would result in random variations in organisms which would be result the development of new variations and species.  There is an outstanding article in Scientific American, From Atoms to Traits by David M. Kingsley that develops the idea that nature selects favorable variations in organisms, and that random changes in DNA can give rise to changes in an organism’s traits, providing a constant source of variation.
Darwin would also be very pleased with the current level of research his and Wallace’s theory has created.  As the famous biologist Theodosius Dobzhansky said, “nothing in biology makes sense, except in the light of evolution.”

Role Playing Darwin in the Classroom

A friend of mine, on Darwin’s birthday (February 12), would dress up in Victorian attire as a young Charles Darwin, enter his high school biology classroom, and announce that he was the “father of evolution.”  

This is a drawing of Charles Darwin at the time of the Voyage of Beagle.  My teacher friend used this drawing to create an attire to dress as Darwin on his birthday.
This is a drawing of Charles Darwin at the time of the Voyage of Beagle. My teacher friend used this drawing to create an attire to dress as Darwin on his birthday.

Then, he pulled out his iphone, and i-clicked through a series of pictures of the trip Darwin had taken aboard a ship called the Beagle from 1831 – 1836!  At the beginning of the Voyage of Beagle, he hadn’t even begun his research which would lead to his theory of natural selection, and he explained this to the students in class.

The teacher then opened a large box, and carefully lifted out a beautifully crafted wood box, which he called his writing slope.  He smiled, and informed the students that back then, this was his lap top!  He opened the writing slope, and showed the students the large slope that he would write on, and then he opened one of the panels, and lifted out a book, which was one of the 15 journal-type books (field notebooks) that Darwin recorded his observations, drawings, and thoughts about his voyage around the world, but especially the coastline of South America.  The teacher then explained that 15 field notebooks, were used by Darwin to write the popular book which was published as Journal of Researchers into the Natural History and Geology of the Countries Visited During the Voyage of H.M.S. Beagle Round the World.  It later became known simply as The Voyage of the Beagle.  My teacher friend explains to his students that Darwin’s field-notebooks is one of the reasons he has them keep a journal of their thinking and reflections in biology class. 

When Darwin returned to England he had collected a massive number of fossils, and animals and plants, and he consulted experts, including zoologists, anatomists, and geologists to help him identify, classify and discuss his collections.  During this period of collaboration, Darwin worked on various books, including The Voyage of the Beagle, but also a series of geology publications, and sketched his ideas about species varieties, and how this might have happened.  Darwin was also an avid reader, and one of the publications he read was Malthus’s .  He is what happened as a result of reading this book, in Darwin’s words:

In October 1838, that is, fifteen months after I had begun my systematic enquiry, I happened to read for amusement Malthus on Population, and being well prepared to appreciate the struggle for existence which everywhere goes on from long-continued observation of the habits of animals and plants, it at once struck me that under these circumstances favourable variations would tend to be preserved, and unfavourable ones to be destroyed. The result of this would be the formation of new species. Here, then, I had at last got a theory by which to work..

And of course the theory that emerged for Darwin was natural selection. Here is how Darwin stated his theory (from his book, On the Origin of Species): 

As many more individuals of each species are born than can possibly survive; and as, consequently, there is a frequently recurring struggle for existence, it follows that any being, if it vary however slightly in any manner profitable to itself, under the complex and sometimes varying conditions of life, will have a better chance of surviving, and thus be naturally selected. From the strong principle of inheritance, any selected variety will tend to propagate its new and modified form. (Source: Charles Darwin, On the Origin of the Species).

My friend used this information to tell a story about Charles Darwin, hoping this might bring the students closer to an understanding about the nature of science, and how ideas come about.  In Darwin’s case, the story told so far in this post is extremely incomplete, but I encourage you to use it to develop your own story with your students. 

You might ask a colleague to dress as Alfred Russell Wallace.
You might ask a colleague to dress as Alfred Russell Wallace, and include him in on a discussion of the co-discovery of the theory of evolution by means of natural selection.




You might want to dress as Charles Darwin as he looked later in life.
You might want to dress as Charles Darwin as he looked later in life.

The 200th Anniversary of The Father of Evolution

This is the 200th anniversary of the birth of Charles Darwin, who was born February 12, 1809, which is the same day that Abraham Lincoln was born.  Darwin, according to one of our grandsons, is the “father of evolution,” (see yesterday’s post).

Two recent publications devote considerable space to Charles Darwin and Evolution.  The January issue of Scientific American, is a special issue “on the most powerful idea in science.”  It includes 10 articles ranging from natural selection at the level of DNA to an article on creationism, intelligent design and the teaching of evolution in school (I’ll discuss this tomorrow).

You can listen to a podcast of The Evolution of Evolution in which the editor-in-chief of SA discusses the special issue that not only marks Darwin’s birthday, but also marks the 150th year since the publication of his book, On the Origin of Species by Means of Natural Selection.  The podcast is interesting in setting the stage for reading the other articles in the issue.  Darwin had received a letter from Alfred Russell Wallace, in which Wallace was seeking Darwin’s feedback on his ideas about evolution, more specifically natural selection.  Darwin, according to some, was shocked and realized that Wallace had come to the same conclusion as he had, the species evolved by means of natural selection.  

Alfred Russell Wallace, the co-discoverer of the theory of evolution by natural selection
Alfred Russell Wallace, the co-discoverer of the theory of evolution by natural selection (Source:

Wallace’s paper and Darwin’s various notes and correspondence on the subject were read at the same Linnaean Society meeting, in London on July 1, 1858. In 1859, Darwin completed the manuscript he had started 20 years earlier, and published his now famous book on evolution.  One writer put their relationship this way:


Although Wallace independently reached the same conclusion, it has usually been Darwin’s name alone associated with the theory of natural selection. Wallace expressed no resentment at receiving less credit. He remained a gracious man to the last, commenting late in life that his greatest achievement had been to prompt Darwin to publish his own theory. Darwin, in turn, proved to be a good friend to Wallace — recalling “how generous and noble was his disposition” in his autobiography, and campaigning vigorously to secure Wallace a government pension he desperately needed. Wallace, it turned out, had no more skill in managing money than his father. (Michon Scott)

Two articles about Darwin are featured in the February 2009 issue of National Geographic: Darwin’s First Clues and Modern Darwins. In Darwin’s First Clues, David Quammen writes a wonderful and exacting story of Darwin’s beginnings aboard the Beagle during the period 1831 – 1836.  It was on this voyage, in which Darwin, who was invited on the ship to be a dining companion for the ship’s captain, and as time went on during the voyage, Darwin began to think of himself as the ship’s naturalist.  The purpose of the voyage of the Beagle was to map the coastlines of South America.  Darwin was able to spend most of his time on land exploring the geology and animals and plant life for five years.

Darwin's route of passage aboard the Beagle. (Source:
Darwin's route of passage aboard the Beagle. (Source:

Quammen discusses how Darwin collaborated with experts in England (on fossil mammals, reptiles, and birds), and used his observations and his scientific writing (in his notebooks) to put together his idea on how species transformed, one from another.  Quammen comments:

About a year and a half later, after adding one crucial piece to his thinking (the idea of excess reproduction and struggle for existence, adopted from an essay on human population by Thomas Malthus), Darwin hit upon his theory: natural selection, whereby the best adapted individuals of each population survive to leave offspring and other’s don’t.  Then he nurtured, refined, developed, and concealed that theory for 20 years, until a younger man named Alfred Russell Wallace struck upon the same idea, forcing Darwin to rush to get his own ready for print.


Darwin’s First Clues: He was inspired by fossils of armadillos and sloths. Link to the article and discover more about Darwin’s ideas and how they were constructed and developed.

Darwin’s Secret Notebooks: National Geographic Channel, TUE FEB 10 9P

Morphed: National Geographic Channel, Begins SUN FEB 8 8P.  Dig 230 million years back into the fossil record to witness the first dinosaur and other dinosaur species as they respond to changes in the earths environment. This led to an amazing, transitional fossil of a creature that was both bird and dinosaur.

The Evolution of Evolution Theory: NPR Talk of the Nation, May 21, 2004 · How did Charles Darwin’s theory of evolution evolve? A look at the state of science leading up to Darwin’s voyage on the Beagle. What scientists influenced his thinking, and what did he see that others before him had not? How has Darwin’s theory of descent with modification itself been modified? Discussion with historian and Pulitzer Prize winner Edward Larson, author of Evolution: the Remarkable History of a Scientific Theory.

Darwin200: Darwin200 is a national programme of events celebrating Charles Darwin’s scientific ideas and their impact around his two hundredth birthday on 12 February 2009, National History Museum, London.  This is a great website.

Darwin’s Voyage on the Beagle: Interactive website on the National History Museum site.

Intelligent Design Again in the News

Last Sunday (3/12/06), the Rev. Nelson Price of Marietta, GA wrote in his Sunday column in the Marietta Daily Journal, “Intelligent design infers there was a designer.” He brought up old arguments related to the issue: scientists are stifling free speech by not allowing intelligent design into the classroom of science; our youth are being protected from such dangerous concepts at I.D.; some things in nature are just too complex to have evolved by means of natural selection—a designer needed to step in and form these complex systems whole; the watch and watchmaker analogy; the orbit of the earth is just right because of an intelligent designer (this is a new one).

In response to Price’s article was one (3/15/06)by Ed Buckner, Southern Director, Council for Secular Humanism. The article, entitled Price wrong again about Intelligent Design claimed that Price’s column was nothing but old wine in a new bottle, and the wine had soured.

I submitted an article to the MDJ after reading Price’s article. Here it is:

Scientific Explanations need to underscore science teaching

I look forward to reading Rev. Price’s Sunday editorial in the Marietta Daily Journal. I generally find the discussions in his pieces thoughtful. I was, therefore, surprised at his piece last Sunday, entitled “Intelligent design infers there was a designer. I am surprised that Rev. Price does not see the religious basis for intelligent design, when interestingly he was arguing that it was a scientific idea, and that our youth were being prevented from learning about this idea.

Centuries before Charles Darwin and Alfred Russell Wallace (co-discoverers of the theory of evolution by natural selection), were born, the idea that an intelligent designer was responsible for an organism’s complexity was well know. The leading proponent of the idea was the English theologian Richard Paley creator of the famous watchmaker analogy, written in 1802, that Rev. Price referred to in his piece. Paley’s idea of an intelligent designer was replaced by the theory of evolution by natural selection about 50 years later when Darwin published his famous book, On the Origin of Species by Means of Natural Selection. In 2005, two books were published on Darwin’s contribution. Each book was edited by two well known scientists, James D. Watson and Edward O. Wilson. Each book contained four of Charles Darwin’s books, including his “On the Origin of Species by Means of Natural Selection.

The idea of intelligent design was revived in 1991 by U.C. Berkeley law professor Philip Johnson after he had a religious conversion, in his book, “Darwin on Trial”. Later Johnson joined with the Discovery Institute in Seattle to promote the idea by affecting change in the curriculum of the nation’s schools. Not through research (as they claim) but through press releases and propaganda. Johnson’s idea, known as “wedge theory” is designed to drive a wedge (as to split a log) into evolutionary biology. There is no research agenda; but there is a very rigorous public relations program.

The science education community has not been involved trying to hold our youth hostage or protecting them from ideas such as intelligent design. Instead our youth have been pawns in a game led by real activists—the Discovery Institute and the Thomas More Law Center whose goal is to wedge their way into science classrooms through intimidation and propaganda.

Rev. Price refers to a “ever-expanding cadre of academicians” that are associated with the intelligent design movement. An analysis of these academicians reveals that very few of them are in the field of science and most are lawyers, government employees, engineers, and theologians. There is no scientific basis for intelligent design, even though Rev. Price claims that there is. The Discovery Institute does not have a scientific research program, and the central concept of the intelligent design ideology, irreducible complexity (in lay terms, some things are so complex they came into being whole—e.g. requiring an intelligent designer). The example they use over and over again is that bacterial cells are propelled by rotary type engines called flagella motors. According to Michael Behe (I.D. proponent), the rotary motor is irreducibly complex, it couldn’t have come into being via natural selection; it must have come into being whole. The problem is that this is not true. Parts can be removed, and it still works. Flagella came into being through natural selection.

The flaw here is that I.D. proponents want to define intelligent design negatively, as anything that is not chance or necessity. Science requires positive evidence. And this is what Charles Darwin and Alfred Russell Wallace did independent of each other.

And finally, the orb of the Earth’s orbit that Rev. Price mentions was explained centuries ago for Sir Isaac Newton in his Universal Law of Gravity, or should we rename it the Theory of Gravity.

Darwin, like Newton, proposed a scientific rather than a religious explanation: the fit between organisms and environments is the result of natural selection. Like all scientific explanations, his relies on natural causation. And this is the kind of thinking that should be espoused in science classrooms.