... thirteen aluminum atoms grouped together in the right way do a killer bromine, the two entities indistinguishable in chemical reactions.
Sam KeanThe emerging and vital truth isn’t who is more Neanderthal than whom. It’s that all peoples, everywhere, enjoyed archaic human lovers whenever they could. These DNA memories are buried deeper inside us than even our ids, and they remind us that the grand saga of how humans spread across the globe will need some personal, private, all-too-human amendments and annotations—rendezvous here, elopements there, and the commingling of genes most everywhere.
Sam KeanThe irony is too rich not to point out. When arranging the different human races in tiers, from just below the angels to just above the brutes, smug racialist scientists of the 1800s always equated black skin with ‘subhuman’ beasts like Neanderthals. But facts is facts: pure Nordic Europeans carry far more Neanderthal DNA than any modern African.
Sam KeanIn a touch Buckland would have appreciated, this multipronged dispersal from Africa is sometimes called the Weak Garden of Eden theory. But this tale is actually better than the biblical version; we didn’t lose Eden but learned to make other Edens across the world.
Sam KeanFor ages anthropologists lumped all African peoples into one ‘race,’ but the genetic truth is that the larger world’s diversity is more or less a subset of African diversity.
Sam KeanBut for years questions persisted about whether most cannibalism was religiously motivated and selective or culinary and routine. DNA suggests routine. Every known ethnic group worldwide has one of two genetic signatures that help our bodies fight off certain diseases that cannibals catch, especially mad-cow-like diseases that come from eating each other’s brains. This defensive DNA almost certainly wouldn’t have become fixed worldwide if it hadn’t once been all too necessary.
Sam KeanGreat literature remains great when it says new things to new generations, and the loops of a knot quite nicely parallel the contours and convolutions of Carroll’s plot anyway.What’s more, he probably would have been delighted at how this whimsical branch of math invaded the real world and became crucial to understanding our biology.
Sam KeanFruit fly scientists, God bless ‘em, are the big exceptions. Morgan’s team always picked sensibly descriptive names for mutant genes, like ‘speck,’ ‘beaded,’ ‘rudimentary,’ ‘white,’ and ‘abnormal.’ And this tradition continues today, as the names of most fruit fly genes eschew jargon and even shade whimsical… The ‘turnip’ gene makes flies stupid. ‘Tudor’ leaves males (as with Henry VIII) childless. ‘Cleopatra’ can kill flies when it interacts with another gene, ‘asp.’ ‘Cheap date’ leaves flies exceptionally tipsy after a sip of alcohol… And thankfully, this whimsy with names has inspired the occasional zinger in other areas of genetics… The backronym for the “POK erythroid myeloid ontogenic” gene in mice—‘pokemon’—nearly provoked a lawsuit, since the ‘pokemon’ gene (now known, sigh, as ‘zbtb7’) contributes to the spread of cancer, and the lawyers for the Pokemon media empire didn’t want their cute little pocket monsters confused with tumors.
Sam KeanFurthermore, because silicon packs on more protons than carbon, it's bulkier, like carbon with fifty extra pounds. Sometimes that's not a big deal. Silicon might substitute adequately for carbon in the Martian equivalent of fats or proteins. But carbon also contorts itself into ringed molecules we call sugars. Rings are states of high-tension- which means they store lots of energy-and silicon just isn't supple enough to bend into the right position to form rings. In a related problem, silicon atoms cannot squeeze their electrons into tight spaces for double bonds, which appear in virtually every complicated biochemical.
Sam KeanAcid strength is measured by the pH scale, with lower numbers being stronger, and in 2005 a chemist from New Zealand invented a boron-based acid called a carborane, with a pH of -18
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