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 at http://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

 was a respected physician, a well known poet, philosopher, botanist, and naturalist.

2. Jean Baptiste Lamarck was famous for his discredited theory of heredity, the "inheritance of acquired traits."  He also was a zoologist and as a forerunner of evolution.  

3. Georges Cuvier found vertebrate paleontology as a scientific discipline and created the comparative method of organism biology. He contributed an immense amount of research in vertebrate and invertebrate zoology and paleontology, and also wrote and lectured on the history of science. 

4. Thomas Malthushad observed that nature plants and animals produce far more offspring than can survive. His view is that there were natural outcomes of population growth and food supply was not popular among social reformers who believed that with proper social structures.

Part 2.

Use your browser to go to the Why Files' "Treasures of Evolution Island" at http://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?

A-He had learned that species change in response to the environment as the losers are culled and the winners have more young which perpetuate those winning characteristics. a rich assemblage of related species had arrived -- or developed -- after the islands emerged from the ocean.

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?

A-  He learned that his finches comprised :13 species and further finch research did prove that the species are related, and that their evolution could be observed in real time.

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

A-"Darwin wanted to know, why do you have four different species, when one species certainly seems good for all the islands."  The pattern is that three islands each housed one species, and one species lived on all the other islands.