Genetic Language is Abstract and Flexible

The awesome power that genetic engineering will one day place in our hands was foreshadowed recently by some experimenters at the University of Basel in Switzerland. Walter Gehring and his students were studying the effects of the eyeless gene in fruit flies. The gene is called eyeless because its absence causes flies to grow without eyes. The gene actually causes eyes to grow. Gehring and the students inserted the gene into various tissues of embryonic flies, and the embryos grew into flies ...

 DNA Divergence is in How You Count

It’s a common misconception that chimp DNA differs from Homo sapiens sapiens genes by only a single percent, but this number is apocryphal. In actuality, the degree of similarity of human and chimp genetic code depends mostly on how you count. Since all complex organisms from Earth possess great swaths of junk DNA inherited from a distant common ancestor, there tends to be startling similarity between many organisms. Sure, humans are like chimps—but they’re also like flatworms and fruit...

 Postmating Competition

Sexual selection doesn’t end with the sex act itself: males can continue to compete even after mating. In many species, females mate with more than one male over a short period of time. After a male inseminates a female, how can he prevent other males from fertilizing her and stealing his paternity? This postmating competition has produced some of the most intriguing features built by sexual selection. Sometimes a male hangs around after mating, guarding his female against other suitors. Wh...