John Derbyshire: Genomics, Humanity's Past, and Humanity's Future
[John Derbyshire is an NRO columnist and author, most recently, of We Are Doomed: Reclaiming Conservative Pessimism.]
The science news this month was dominated by two genome stories. An organism’s genome is the sum total of all its genetic information — its DNA. In sexually reproducing species, a child gets half its genome from one parent, half from the other. Asexual organisms like bacteria just copy DNA from one generation to the next. In both cases, there are occasional copying errors, which serve to make life (as it were) interesting....
In the few millennia prior to 30,000 b.c., our remote ancestors in Europe and the Middle East, whither they had spread after leaving Africa, were sharing those territories with an older stock, the Neanderthals. Around 30,000 b.c. the Neanderthals disappear from the archeological record, leaving our ancestors in sole possession of the turf (tundra, whatever). Were we and they separate species — Homo sapiens and Homo neanderthalensis? Or two distant breeds of the same species — Homo sapiens sapiens and Homo sapiens neanderthalensis? A closely related issue is: Could the two stocks cross-mate, producing fertile offspring?
Apparently they could, and did. That’s what we learned this month. A team of biologists in Germany has for several years been working to figure out from fragments of bone what the DNA of Neanderthals looked like. We already know what modern Homo sap. DNA looks like. (There’s a specimen here.) The researchers now have enough Neanderthal DNA to be able to declare that yes, there was successful cross-mating. The base populations of Homo sap. outside Africa have genomes with 1 to 4 percent of Neanderthal genes.
These are early results, and there are problems to be resolved. So far the archeological timeline seems not to match the genetic timeline (which can be estimated from known rates of genetic change). We also don’t know much about what, if anything, the Neanderthal genes do. “Some of the genes seem to be involved in cognitive function and others in bone structure,” says the New York Times report vaguely. And of course we know nothing about the intimate encounters that must have occurred to produce the gene-mixing, whether they were peaceable or violent. We only know they occurred, between creatures not much different from ourselves, in the unimaginably remote past....
This month’s other genome story concerned the opposite end of the scale, and points us to the future rather than the past. Craig Venter and his colleagues put together a genome from scratch, using off-the-shelf chemicals, and swapped it for the genome of a living organism, a wee one-celled asexual critter named Mycoplasma capricolum (which, as its name suggests, causes goats to feel unwell). Then they put the transformed cells on dishes of jelly and waited for them to reproduce. The cells did so, very happily, and there are now several billion individuals of this new organism with its made-up genome. (A cell contains much more than a genome; but all the other bits are templated in the genome, and after a few dozen generations Dr. Venter’s invented genome was calling the cell-construction shots.)...
Craig Venter’s result knocks away another prop from under our folk metaphysics, by killing vitalism once and for all. Living processes, presumably including those that comprise human thought and feeling, are complicated chemical reactions. Sure, you can still think up arguments for vitalism, ensoulment, and human exceptionalism; but those arguments are, by some small degree, a harder sell this month than they were last month, and they will get harder yet.
The consequences, it seems to me, will not be good. Our folk metaphysics is false; the facts uncovered by science are true. Can we live without comforting falsehoods, though? Or rather: How many of us can?...
Read entire article at National Review
The science news this month was dominated by two genome stories. An organism’s genome is the sum total of all its genetic information — its DNA. In sexually reproducing species, a child gets half its genome from one parent, half from the other. Asexual organisms like bacteria just copy DNA from one generation to the next. In both cases, there are occasional copying errors, which serve to make life (as it were) interesting....
In the few millennia prior to 30,000 b.c., our remote ancestors in Europe and the Middle East, whither they had spread after leaving Africa, were sharing those territories with an older stock, the Neanderthals. Around 30,000 b.c. the Neanderthals disappear from the archeological record, leaving our ancestors in sole possession of the turf (tundra, whatever). Were we and they separate species — Homo sapiens and Homo neanderthalensis? Or two distant breeds of the same species — Homo sapiens sapiens and Homo sapiens neanderthalensis? A closely related issue is: Could the two stocks cross-mate, producing fertile offspring?
Apparently they could, and did. That’s what we learned this month. A team of biologists in Germany has for several years been working to figure out from fragments of bone what the DNA of Neanderthals looked like. We already know what modern Homo sap. DNA looks like. (There’s a specimen here.) The researchers now have enough Neanderthal DNA to be able to declare that yes, there was successful cross-mating. The base populations of Homo sap. outside Africa have genomes with 1 to 4 percent of Neanderthal genes.
These are early results, and there are problems to be resolved. So far the archeological timeline seems not to match the genetic timeline (which can be estimated from known rates of genetic change). We also don’t know much about what, if anything, the Neanderthal genes do. “Some of the genes seem to be involved in cognitive function and others in bone structure,” says the New York Times report vaguely. And of course we know nothing about the intimate encounters that must have occurred to produce the gene-mixing, whether they were peaceable or violent. We only know they occurred, between creatures not much different from ourselves, in the unimaginably remote past....
This month’s other genome story concerned the opposite end of the scale, and points us to the future rather than the past. Craig Venter and his colleagues put together a genome from scratch, using off-the-shelf chemicals, and swapped it for the genome of a living organism, a wee one-celled asexual critter named Mycoplasma capricolum (which, as its name suggests, causes goats to feel unwell). Then they put the transformed cells on dishes of jelly and waited for them to reproduce. The cells did so, very happily, and there are now several billion individuals of this new organism with its made-up genome. (A cell contains much more than a genome; but all the other bits are templated in the genome, and after a few dozen generations Dr. Venter’s invented genome was calling the cell-construction shots.)...
Craig Venter’s result knocks away another prop from under our folk metaphysics, by killing vitalism once and for all. Living processes, presumably including those that comprise human thought and feeling, are complicated chemical reactions. Sure, you can still think up arguments for vitalism, ensoulment, and human exceptionalism; but those arguments are, by some small degree, a harder sell this month than they were last month, and they will get harder yet.
The consequences, it seems to me, will not be good. Our folk metaphysics is false; the facts uncovered by science are true. Can we live without comforting falsehoods, though? Or rather: How many of us can?...