Everyone has sex eventually.
Topic: Sex
Interesting article over at PLOS:
Convergent Evolution of Chromosomal Sex-Determining Regions in the Animal and Fungal Kingdoms. The late S.J. Gould liked to emphasize the importance of
contingency and expressed skepticism that the shape of life would manifest itself in the same way if one could rewind the clock of natural history by fiat and allow evolution to do its work once more. Well, research that offers evidence as above undercuts the force of such musings (though those who deny the seminal importance of natural selection in evolution might argue that they would concede there are broad parameters that natural history must always be constrained by). What language is to evolutionary psychology sex is to evolutionary biology, the mother of a million papers and the patron of a thousand careers. Nevertheless, I will offer that in an ecosystem characterized by species plentitude and competition
sex will evolve (see
Narrow Roads of Gene Land: Volume 2 for more details on why complex organisms must be sexual organisms). Some might ridicule science fiction for the tendency for many of the "aliens" to simply be humans with strange growths on their noses. Some authors like Ursula K. Le Guin have offered worlds where conventional ideas of sex/gender are confounded in an effort to break out of the box of anthropomorphism. But I would be surprised if hermaphroditic sentient beings were common on
earth-like planets (I have no idea how natural selection would shape organisms on gas giants for example). Certainly there are novel sexual life cycles among certain species, but they are usually exceptions that prove the rule.
1 The lesson that biology, and science in general, offers is that diversity exists constrained by certain parameters, what we like to call reality. This does not imply that there is one way to go from A to B, but some of the paths might be favored over others. The reality of physics is relatively transparent in its exposition, but just because biology is messier, more statistical, does not mean that its lessons don't have any utility.
1 -
Amazon mollies "...are a unisexual (all female) species of molly that are parasitic on the closely related bisexual sailfin molly, P. latipinna. Conflict exists between male sailfin mollies trying to mate with the right species, and the unisexual females trying to appropriate a mating from these males...."
Gene Expression: read the rest
here.
Posted by mediafaction
at 12:01 AM EST
Updated: Saturday, 20 November 2004 11:22 AM EST