22 April 2007

If You Want To Fit In, Get A Salary...

Mutations are essential to evolution theory, but mutations can only eliminate traits. They cannot produce new features.

On the contrary, biology has catalogued many traits produced by 'point' mutations (changes at precise positions in an organism's DNA) bacterial resistance to antibiotics, for example.

Mutations that arise in the Hox (homeobox) family of development-regulating genes in animals can also have complex effects. Hox genes direct where legs, wings, antennae and all those other body segments should grow.

Further, molecular biology has discovered mechanisms for genetic change that go beyond point mutations and these expand the ways in which new traits can appear. Functional modules within genes can be spliced together in novel ways. Whole genes can be accidentally duplicated in an organism's DNA and the duplicates are free to mutate into genes for new, potentially complex features.

Comparisons of the DNA from a wide variety of organisms indicate that this is how the globin family of blood proteins evolved over millions of years.


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