martes, 27 de abril de 2010

"Arrival of the Fittest?"

It has now been over 150 years since Charles Darwin´s influential work "The Origin of Species" first espoused the ideas of evolution by means of natural selection, or "survival of the fittest." But as scientists more closely examine the idea that these evolutionary changes happen slowly over time, many object. Many are finding that incredibly complicated changes happen not through gradual change over time, but through relatively simple changes in the genetic code that have extremely un-simple effects on the organism. This field, known as eco-devo, is gaining popularity among evolutionary scientists after largely being ignored for the better part of the last century. This has lead scientists to now believe that while changes in life on a broader scale are "gradual over time," most specific changes just simply "arrive."

One example of this come from a gene responsible for the growth of the beak of a finch. Scientists have shown that by simply activating the gene BMP4, the birds grow beaks up to twice as large as ones without. The gene is present in all types of finches, but is only activated in some types. Dr. Sean B. Carroll says that these discoveries really "blow people´s minds to know that changes once thought to be extremely complex can really be quite simple mutations." This may not be THE driving force in evolution, but it´s presence as a major one is definitely gaining credibility among many scientists who study evolution.

Zach Ming

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