By studying one of the great mysteries of biology the evolution of sexual reproduction Ricardo Azevedo, an assistant professor in the department of biology and biochemistry at UH, has found in a study using a computational model that a leading theory may be more plausible than previously thought, His findings are described in a paper titled "Sexual Reproduction Selects for Robustness and Negative Epistasis in Artificial Gene Networks," appearing in the current issue of Nature, the weekly scientific journal for biological and physical sciences research.

Collaborating with Christina Burch from the University of North Carolina at Chapel Hill, Azevedo and his team created a very simple model of how genes interact with each other to produce an organism and simulated the evolution of this simple genetic system under different conditions. What they found was quite surprising sexual reproduction itself can lead to the evolution of a special feature of the genetic architecture known as negative epistasis that, in turn, confers an evolutionary advantage to sexually reproducing organisms. In other words, sexual reproduction may be self-reinforcing. They also found that sexually reproducing populations evolved an increased robustness to mutations when compared to asexual ones.

These findings suggest a good news/bad news scenario when it comes to the evolutionary implications of sex. Sexual populations adapt better to their environments and become more resistant to harmful mutations, but these advantages are more likely to benefit our natural enemies.

According to Azevedo, the issue is that there are many costs associated with sexual reproduction. First, sexually transmitted diseases
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Contact: Lisa Merkl
lkmerkl@uh.edu
713-743-8192
University of Houston
1-Mar-2006