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August 20, 2012

Aphids may be the first photosynthesising animal

Aphids may be first photosynthesising animal - life - 20 August 2012 - New Scientist
Aphids may recharge their batteries as they sit in the sun. A handful of animals live in symbiosis with photosynthetic microbes or plants, but none have been found that harness light directly. Now there are hints that aphids increase their production of ATP – the biological energy molecule – in response to light. While this doesn't prove they photosynthesise, it is an intriguing hint that they might. Carotenoids are common in algae and some bacteria and fungi, where they harvest light for photosynthesis. Aphids are the only insects known to have the genes to produce carotenoids; the molecules give them their colour.

August 15, 2012

Are you ready for antibiotic-resistant super gonorrhea?

Dear American Dumbasses, when you are prescribed a course of antibiotics please take the entire course. Do not quit when your symptoms abate. Or you may just give rise to the next superbug. Sincerely, My genitalia Here It Comes: Super Gonorrhea :-/ - James Hamblin - The Atlantic
I just got out of a telebriefing with the CDC. The atmosphere was not a jovial one. The words "gonorrhea epidemic" were thrown around in ominous tones. No one was up for hanging out after. Did you know gonorrhea can kill you? It can, and it's also tragically effective at making women infertile. According to her journals, my great aunt Mabel was "barren," and my grandmother always told me it was probably from gonorrhea. The only reason we don't hear about these awful complications more often -- and we instead think of it as a little oops of an infection ("Can I still drink on these antibiotics?" "Yes." "Cool.") -- is because we've been able to kill it early with relative ease. But over the past decades, gonorrhea has been mowing down our antibiotics. If this was the Olympic 400 IM, gonorrhea would be the Ryan Lochte and our antibiotics would be the guy from Moldova. The list of effective antibiotics has been dwindling as the bacteria became resistant, and now it's down to one. Five years ago, the CDC said fluoroquinolones were no longer effective, but oral cephalosporins were still a common/easy treatment. Now injected ceftriaxone is the only recommended effective drug we have left. And it has to be given along with either azithromycin or doxycycline.

August 14, 2012

That thing about ancient Europeans breeding with Neanderthals probably isn't true

Instead, it's likely that they just share a smidgeon of DNA from a common primate ancestor. Ancient humans may not have interbred with Neanderthals, after all
But what if the consensus is wrong? What if those genetic remnants were inherited not from Neanderthals, but from a common ancestor, an evolutionary forebear to both humans and Neanderthals? A newly published study by researchers at the University of Cambridge suggests it's possible. In a study recounted in the latest issue of Proceedings of the National Academy of Sciences, a team of researchers led by evolutionary biologist Andrea Manica used computer models to simulate the last 500,000 years of population dynamics in Europe and Africa, under the assumption that there were two major migrations out of Africa. In the first migration, the common ancestor to modern humans and Neanderthals spread throughout Africa and Europe. In the process, their vast geographic distribution gave rise to genetic heterogeneity, not only between the continents, but within them, as well. The model then posits that between 300 and 350 thousand years ago, the European populations became separated from the African ones. Those populations in the European range evolved into Neanderthals, the African populations into anatomically modern humans. Crucially, however, genetic heterogeneity within each continent was maintained. As a result, modern human populations in northern Africa may have retained chunks of their ancestral DNA that those in the southern reaches of the continent did not, genetic information that they shared with the recently evolved Neanderthals of Europe. When the second migration from Africa took place between 60,000 and 70,000 years ago, these northernmost African populations would have carried these genetic remnants into Europe with them; while those populations lacking the ancestral code remained in Africa.