Tuesday, June 2, 2015

Let’s Talk About Sex For A Change

He/She/He Limpet (Jan Delsing/BioLib)
How about that Bruce Jenner? Makes that trans-sex transformation to female and gets the exclusive and the cover of Vanity Fair which is then picked up by every major and minor news outlet in the world. Reminds me of the time a few years back when the ribbed Mediterranean limpet (Patella ferruginea) was found to be able to change its sex from male to female and back again.

Mr./Mrs. Limpet had neither the vanity nor the desire to try for the cover of Vanity Fair but was described by John R. Platt in a Scientific American blog as nearly extinct and the subject of efforts by scientists to learn how it breeds and reproduces to save it from extinction. (The Incredible Mr./Mrs. Limpet: The Endangered, Sex-Changing Sea Snail)

Most limpet species possess both male and female characteristics and change gender in their lives due to external environmental factors; Patella ferruginea, however, is unusual in changing gender then back again, scientists discovered. When and why still remains a mystery.

The scientists wrote in a paper that, this discovery provides "new direction for research into the mechanisms and factors driving sex change and its effects on the population dynamics" for the species, which may help to inform conservation strategies to keep it from extinction.

Meanwhile, in an attempt to ride the media frenzy on June 1, the endangered smalltooth sawfish muscled in on the news with the discovery that they are resorting to “virgin births” in the wild— perhaps in an effort to survive.

According to The Washington Post, “Female sawfish in Florida estuaries were found to have produced living offspring without the help of a male. Researchers found that 3 percent of sawfish in their study were the result of this unusual reproductive strategy.” (On the verge of extinction, female sawfish resort to ‘virgin births’ to survive)

In rare instances some vertebrate females have been known to switch between sexual and asexual reproduction depending on the availability of a mate. Reproducing without mating is called facultative parthenogenesis where an egg absorbs a genetically identical cell to create offspring about half as genetically diverse as the mother. These offspring often don't survive but enough are around in Florida to be counted.

OK. You read it here and in Scientific American and The Washington Post.

Vanity vanitatum, omnia vanitas.

--Mike Sato

2 comments:

  1. But, but, but .... my reading of Ecclesiastes seems to suggest the notion of "vanity" (and the quote) more as "All is in vain" ... or, of no help or use. Seems like the sea dwelling critters are doing just about the opposite. Probably that is why there are no famous mollusk philosophers? Too busy getting on with it ....

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  2. You are correct and reading "vanity" as some read it as "meaninglessness" or "nothing" is directed by the Preacher to our human endeavors whereas the phenomena of sex change in the non-human world may provide some species survival advantages.

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