CSB #1: Rethinking the Factors of Evolution

Definitions

speciation - the process of how a species evolves so that it is adapted to its environment

allopatric speciation - theoretically what happens when the same species get split geographically: a new species emerges that is adapted to its surroundings

anole - a species of lizard

progenitor - ancestor/original


Summary

People have always believed that separation between a species is the most important factor of evolution ever since Charles Darwin did his observation of finch species in the Galápagos Islands. Roger S. Thorpe, Yann Surget-Groba, and Helena Johansson of Bangor University, United Kingdom researched anoles, a species of small lizards that had been naturally separated over a small cluster of islands, then reunited again after some volcanic activity a million years ago made the four islands become one. Thorpe, Surget-Groba, and Johansson studied the DNA of the anoles from different original islands and the DNA of the anoles from different habitats of the same original island. Surprisingly, there was less of a difference between DNA of anoles from different original islands than difference between the DNA of anoles from different habitats of the same original island.

Discussion

It seems strange that the DNA from the lizards from the same original island but different habitats have more difference than the DNA of lizards from different original islands. I think that it is interesting that we have thought that geographical separation contributes the most to natural selection or evolution since Darwin, but through this research we find out that it may not be so. Furthermore, it may be that different habitats contribute more to speciation than geographical separation. This finding might change a lot of what we think about evolution because much of what we know comes from Darwin’s observations and research. This research may help us better understand species and how new ones form.


Questions

-Does geographical separation really play that big a role in evolution, or is it just because the two land masses usually have different habitats?

-Have people done the same experiment with different animals and came up with the same results?


Resources

Galloway, Evan. "Island Lizards." Science Online. Facts On File, Inc., June
     2010. Web. 23 Sept. 2010.