Mr Darwin

[wild worlds]

Just been looking at the pics that Black has put up in the gallery. Has anyone noticed how small the tusks are of most of the elephant pics in this and other galleries are? I know there are a few "tuskers" about including "Duke" that roams around Lower Sabie/Crocodile Bridge in KNP ,but not many maybe 7-10?
I was chatting about this over a few beers with a mate a while ago. His theory is that years of slaughter has eradicated of many of the eles that are naturally “big tuskers” and the result is that the naturally smaller tusked animals are those that are breeding.(big tuskers being the prefered mate)
He went on to expound that he believes this shows that Darwin’s theory of evolution is proved beyond doubt within a very short space of time.
Even in the cold light of a hangover it seemed to make sense. I suppose if this theory is correct, what has taken only decades to change by man will take thousands of years to put back, taking into account the lifespan of an ele? Any opinions? WW

[paul m]

Yes, this is artificial selection which was well known way before Darwin - it's how we get tame pigs, cows, sheep etc.. If hunters go for the largest/biggest tusked/brightest feathered/whatever type of prey then they will select against the genes that cause whatever feature we're talking about. So yes, shooting the biggest tuskers will reduce the proportion of these in the gneral population but it doesn't prove very much about evolution I'm afraid.

Darwin's theory of evolution is based on natural selection - it was well known that you could artificially select properties to breed for domestic animals, his concern was about how wild animals ecolved. What your observations show is that humans can have an effect on selection in (perhaps) semi-natural populations - the herds of elephants are being manipulated by humans in much the same way as sheep/goats, cows/buffalos, boar/pigs and what have you, have been ....

Originally Posted by wild worlds

Just been looking at the pics that Black has put up in the gallery. Has anyone noticed how small the tusks are of most of the elephant pics in this and other galleries are? I know there are a few "tuskers" about including "Duke" that roams around Lower Sabie/Crocodile Bridge in KNP ,but not many maybe 7-10?
I was chatting about this over a few beers with a mate a while ago. His theory is that years of slaughter has eradicated of many of the eles that are naturally “big tuskers” and the result is that the naturally smaller tusked animals are those that are breeding.(big tuskers being the prefered mate)
He went on to expound that he believes this shows that Darwin’s theory of evolution is proved beyond doubt within a very short space of time.
Even in the cold light of a hangover it seemed to make sense. I suppose if this theory is correct, what has taken only decades to change by man will take thousands of years to put back, taking into account the lifespan of an ele? Any opinions? WW

[black]

It's scary to think how much effect poaching can have. I've read that the propagation of the absent-tusk gene has resulted in the birth of large numbers of tuskless elephants, now approaching 30% in some populations (compare with a rate of about 1% in 1930). Tusklessness, once a very rare genetic abnormality, has become a widespread hereditary trait. It is possible, if unlikely, that continued poaching could bring about a complete absence of tusks in African elephants, a development normally requiring thousands of years of evolution. The effect of tuskless elephants on the environment, and on the elephants themselves, could be dramatic. Elephants use their tusks to root around in the ground for necessary minerals, tear apart vegetation, and spar with one another for mating rights.

There are of course other factors at work affecting tusk size in certain elephant populations. The tusks of Namibian elephants are more brittle than those of other elephants, due to a mineral deficiency, and so break easily when the elephant scrapes bark off trees, digs or fights.