"If you own a birdbath, chances are you’re hosting one of evolutionary biology’s most puzzling enigmas: bdelloid rotifers. These microscopic invertebrates—widely distributed in mosses, creeks, ponds, and other freshwater repositories—abandoned sex perhaps 100 million years ago, yet have apparently diverged into nearly 400 species. Bdelloids (the “b” is silent) reproduce through parthenogenesis, which generates offspring with essentially the same genome as their mother from unfertilized eggs. Biologists have yet to find males, hermaphrodites, or any trace of meiosis—the process that creates sex cells—challenging the long-held assumption that evolutionary success requires genetic exchange.
The genetic variation created by meiosis and fertilization, theory holds, bolsters a species’s capacity to weather shifting environmental conditions or resist rapidly evolving parasites. (During meiosis, the genome splits in two, and chromosome pairs swap bits of their DNA; during fertilization, the sex cells fuse to restore the complete genome.) Many multicellular eukaryotes pass through a sexual and asexual phase in their life cycle. But eschewing sex altogether, à la bdelloids, is not theoretically consistent with a long-lived evolutionary life span or extensive species diversification."
Also: BBC Nature - Stick insects survive one million years without sex
Men, you want more bad news?
Cisco fired 6,500 people.
Borders Bookstore goes out of business, closing 400 stores and laying-off 11,000 people.
What do YOU prefer: not getting laid, or not getting laid-off?
It's a...grave new world.
"Living lives of quiet desperation." :)
A non-traditional maxicard that I made with a book cover (cool cougar) bought from a Borders bookstore
(see their barcode label?).
Enjoy while you can, whatever that is...
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Please visit and join the ABC Wednesday meme!
well, of your choices, both kinda suck
ReplyDeleteah, asexual reproduction!
ROG, ABC Wednesday team
Obviously asexuality has its place in the world!
ReplyDelete