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Scott’s List: What’s Hot in Evolutionary Biology
By Scott Lanyon
Spring 2007
The Bell Museum’s January Café Scientifique on the topic of evolution featured an open discussion between scientists and the beer-drinking public that, while lively, was also a microcosm of K-12 science education: too much time spent talking about why some people want to ignore scientific facts and theories and too little time spent actually learning about those scientific facts and theories. I sympathized with the disappointed audience member who expressed that what he really wanted to hear about were the hottest topics in evolutionary biology today.
So, until we can hold another Café on this topic, I thought that the least I could do is use this column to provide a quick response to that audience member’s request. Here then is Scott’s list of evolution’s current hot fields. In my opinion, the greatest advances in evolutionary biology today are being made in increasing our understanding of: 1) the tree of life, 2) how entire genomes evolve, and 3) the role of development in evolution.
Our knowledge of the tree of life—the genealogy for all life on Earth—has grown exponentially in recent years as a result of new DNA sequencing techniques, faster and more powerful computers and software, increased funding from the National Science Foundation, and a great deal of hard work by scientists (including many of the Bell Museum’s researchers). What was once considered unknowable is now being revealed at a phenomenal rate with profound implications for all of the biological sciences. We are closer than we have ever been to mapping the evolutionary relationships among all organisms on our planet—an accomplishment that is increasingly seen as providing the intellectual foundation for a wide variety of scientific disciplines.
The tree of life is mapped by studying a handful of genes of tens of thousands of species. At the same time, other scientists are studying all the genes of a handful of species in order to understand what genes are present, what they do, and how they interact. The ability to study whole genomes of organisms (as was done in the Human Genome Project) allows biologists to study evolutionary patterns and processes in a much more integrated manner than ever before. One of the reasons a genome perspective is proving so valuable is that, increasingly, we need to understand not only which genes are involved in the expression of a particular trait, but also how those genes interact.
Nowhere is this more evident than at the intersection of of evolutionary biology and developmental biology—an emerging field of study dubbed “EvoDevo.” The popular conception of gentics is that a particular gene codes for a particular product (e.g., flower color), with the understanding that there can be different versions of that gene that produce different variants of its product (i.e., different flower colors in different individual plants). However, in recent years developmental biologists have gained a better understanding of a different kind of gene (a kind of regulatory gene) that doesn’t code for a particular product directly, but rather controls when and where other genes produce products. The evolutionary significance of this discovery is that minor mutations in regulatory genes can and do produce dramatic changes in gene products. Insects have six legs, spiders eight, and centipedes considerably more. These differences are huge but scientists have concluded that they evolved as the result of small mutations in regulatory genes. Research today is discovering myriad new ways in which evolution in regulatory genes has played a major role in evolutionary history.
These three fields are not only changing the nature of evolutionary biology but also are having a profound effect on the life sciences as a whole. These and other exciting areas of research will be the subject of upcoming Cafés, and promise to fundamentally alter our understanding of the history of life on Earth.
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