EXPLORING THE ROOTS OF EVOLUTIONARY THEORY

Awareness of biological evolution emerged over centuries through the cumulative observations of many naturalists, biogeographers, comparative anatomists, and paleontologists. When Darwin and Wallace in the mid-1800s arrived at the idea of evolution by natural selection, they had been influenced not only by their own travels and observations, but also by the writings of many of their predecessors. Darwin's ideas were also influenced by his travels as a young naturalist on the H.M.S. Beagle. The islands he explored off the coast of Ecuador, the Galapagos, are hotbeds of evolutionary change. However, as you will see, Darwin did not entirely recognize the importance of these islands until after he returned from his voyage.

 Activity

In this activity you will access the evolution section of the University of California's Museum of Paleontology to explore some of the roots of evolutionary biology. You will then visit the Why Files site to learn about Darwin's voyage to the Galapagos and the current state of these islands.

Part 1.

Use your browser to go to the "History of Evolutionary Thought" exhibit at the University of California Berkeley Museum of Paleontology athttp://www.ucmp.berkeley.edu/history/evothought.html

Use the links in this section to learn about and briefly describe the background and scientific contribution of each of the following people:

1. Erasmus Darwin:

         Background- Charles Darwin's grandfather, and was a very intellectual man who was also a physician, a well known poet, philosopher, botanist, and naturalist.

         Scientific Contribution- he formulated one of the first formal theories on evolution in Zoonomia, or, The Laws of Organic Life.

2. Jean Baptiste Lamarck:

         Background- He was the youngest of 11 children and joined the French Army until accidental injury forced him to leave the army. He went on to publish a series of books on invertebrate zoology and paleontology.  His works never became popular in his life time. Passed away on Dec. 28, 1829.

         Scientific Contribution- He created a new field of biology and created the Invertebrates lessons. Never won an award for his work or his work was unpopular because other scientists believed that studying “invertebrates” was unworthy.

                 

3. Georges Cuvier:

         Background- Born in Montbéliard, a French-speaking community in the Jura Mountains.  He was a tutor to a noble family in Normandy, there he began to make his reputation as a naturalist.  He was invited to Paris  by Geoffroy Saint-Hilaire and there he became a professor of animal anatomy.

         Scientific Contribution- He established the fact of the extinction of past lifeforms. He contributed an immense amount of research in vertebrate and invertebrate zoology and paleontology, and  he also wrote and lectured on the history of science.

                 

4. Thomas Malthus:

         Background- Malthus was a political economist who was concerned about, what he saw as, the decline of living conditions in nineteenth century England.

         Scientific Contribution- Natural Selection and his theory that in nature plants and animals produce far more offspring than can survive. He said that man could do this too, but it would be the downfall of men.

Part 2.

Use your browser to go to the Why Files' "Treasures of Evolution Island" athttp://whyfiles.org/125galapagos/index.html

Use the information from Sections 3 and 4 to answer the following questions:

1. What interesting evidence of geological change did Darwin observe while visiting the Galapagos?

         Darwin discovered that South America rose from the ocean. He found rocks that had recently been in the water, with barnacles, and they were 6 feet above sea level. He soon realized that quakes probably accounted for the raised beaches he'd seen in Patagonia. He concluded that ancient shorelines dried out when the land was raised.

2. What did Darwin learn about the Galapagos finches when he returned to England? What vital information had he neglected to record when he collected them?

Darwin neglected to record when and where the Finch came from when he collected them. He learned that finches proved that species can be related.

3. Describe the distribution pattern of Galapagos mockingbirds. What question did this raise in Darwin's mind?

         It raised the question of, “Why do you have four different species, when one species certainly seems good for all the islands?”