"Greg Egan - Mitochondrial Eve" - читать интересную книгу автора (Egan Greg)

with a circular sofa in the middle. Artwork from around the world decorated
the walls, from an uncredited Arnhem Land dot painting to a Francis Bacon
print. The explanatory text below was a worry: dire Jungian psychobabble
about ‘universal primal imagery’ and ‘the collective unconscious’. I groaned
aloud – but when Lena asked what was wrong, I just shook my head innocently.

A man in white trousers and a short white tunic emerged from a camouflaged
door, wheeling a trolley packed with impressively minimalist equipment,
reminiscent of expensive Scandinavian audio gear. He greeted us both as
‘cousin’, and I struggled to keep a straight face. The badge on his tunic
bore his name, Cousin André, a small reflection hologram of Eve, and a
sequence of letters and numbers which identified his mitotype. Lena took
charge, explaining that she was a member, and she’d brought me along to be
sequenced.

After paying the fee – a hundred dollars, blowing my recreation budget for the
next three months – I let Cousin André prick my thumb and squeeze a drop of
blood onto a white absorbent pad, which he fed into one of the machines on the
trolley. A sequence of delicate whirring sounds ensued, conveying a
reassuring sense of precision engineering at work. Which was odd, because I’d
seen ads for similar devices in /Nature/ which boasted of no moving parts at
all.

While we waited for the results, the room dimmed and a large hologram
appeared, projected from the wall in front of us: a micrograph of a single
living cell. /From my own blood?/ More likely, not from anyone’s – just a
convincing photorealist animation.

“Every cell in your body,” Cousin André explained, “contains hundreds or
thousands of mitochondria: tiny power plants which extract energy from
carbohydrates.” The image zoomed in on a translucent organelle, rod-shaped
with rounded ends – rather like a drug capsule. “The majority of the DNA in
any cell is in the nucleus, and comes from both parents – but there’s also DNA
in the mitochondria, inherited from the mother alone. So it’s easier to use
mitochondrial DNA to trace your ancestry.”

He didn’t elaborate, but I’d heard the theory in full several times, starting
with high school biology. Thanks to recombination – the random interchange of
stretches of DNA between paired chromosomes, in the lead-up to the creation of
sperm or ova – every chromosome carried genes from tens of thousands of
different ancestors, stitched together seamlessly. From a palaeogenetic
perspective, analysing nuclear DNA was like trying to make sense of ‘fossils’
which had been forged by cementing together assorted bone fragments from ten
thousand different individuals.

Mitochondrial DNA came, not in paired chromosomes, but in tiny loops called
plasmids. There were hundreds of plasmids in every cell, but they were all
identical, and they all derived from the ovum alone. Mutations aside – one
every 4,000 years or so – your mitochondrial DNA was exactly the same as that
of your mother, your maternal grandmother, great-grandmother, and so on. It