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Remember When Elephants Had Tusks?
Boing Boing links to an interesting story today. If an antibiotic kills 95% of a germ species, but 5% bear a gene for resistance, indiscriminate use of it will result in a surviving line of entirely resistant germs. But on a slightly larger scale, genetically tusk-free elephants are gaining ground relative to their tusked brethren, says one study, thanks to a nasty antibiotic called poaching. If elephants don't have the decency to go extinct, maybe they'll just hang around to tusklessly remind our grandchildren where billiard balls originally came from, and to invite us to ponder what the last poacher was thinking as he shot the last tusked elephant.
It is part of trend. Tens of thousands of years ago, elephants had 6 tusks instead of just 2.
Don't blame Durga. I voted for Centauri.
This same phenomenon has been observed in lakes where extensive sport fishing takes place. Since either by regulations or due to the angler's behaviour the larger fish seem to have the most fishing pressure applied to them. Over time the abundance of large fish decline, and remain low even after many years where not fishing is permitted on the lake. What happens is those fish with the genetic disposition to grow very large have a much lower success rate when it comes to mating, and there fore the genes that allow fish to grow large become increasingly rare.
Just another crappy blog
I have to strongly object to your terminology. Evolution is not an entity or process which can be "forced" into anything. It is simply an observation about what happens in the world.
"Selective pressure" is an incredibly loaded term which anthropomorphizes what's really happening. In this case, what is happening with the elephants is that the ones with tusks are being killed off, and the ones without tusks are not (and it's not any more complicated than that). There is nothing putting "pressure" on the elephants to lose their tusks. The mutations are random and happen without respect to environmental changes. It is the environment which makes some of these mutations more or less favorable but it is not the cause of those mutations.
Suppose you wanted to "force" humans to evolve gills, like fish. Suppose that you did this by rounding up everybody who did not have gills, and drowning them. Do you think this procedure has any chance in hell of causing humans to start growing gills? The reason why not, is that the sort of mutation that could cause that is extremely complex and almost infinitely unlikely. But in the case of the elephants, the tuskless phenotype was present even before the advent of modern hunting.
Evolution has no will, no path, no agenda, no nothing. It can't be forced, pressured, coerced, etc.
Why not just harvest the ivory when the elephant develops maturely sized tusks, instead of killing the animal?
-molo
Using your sig line to advertise for friends is lame.
My simple objection is that poachers are not starving. They are members of organized crime gangs, often so powerful to be able to challenge the state institutions themselves. Poaching is a sistematic process, and it's very "well" tought out: the reason why poachers don't plan for the future (i.e. why they poach all they can and to hell sustainability) is because poaching gangs are compiting against each other. It's a destructive logic, and it makes me revolt, but it's logic.
Sigged!
On CNN the other day, I heard this referred to as "survival of the fittest," which was one of the dumbest things I had heard in weeks. The anchor implied that because tuskless elephants used to be 5% of the elephant population and now they're 8%, this means that more elephants are being born with the tuskless gene, which could be completely false. If I have 100 elephants, 5 of them tuskless, and I kill 37 of the tusked elephants, 8% of the elephants are now tuskless - Darwin it ain't.
THIS was one of the dummest thing I've read in weeks.
If you kill elephants, and some survive because of a genetic trait: It's survival of the fittest.
In this case, the fittest being the ones less likely to be shot due to a genetic predisposition to refrain from growing big shiny tusk with high resale value.
You can't take the sky from me...