Hallo Sconti - Lonesome George der Sexmuffel
Seite 1 von 1 Neuester Beitrag: 09.05.16 23:58 | ||||
| Eröffnet am: | 08.05.07 00:17 | von: Dr.UdoBroem. | Anzahl Beiträge: | 15 |
| Neuester Beitrag: | 09.05.16 23:58 | von: Terrorschwe. | Leser gesamt: | 4.494 |
| Forum: | Talk | Leser heute: | 1 | |
| Bewertet mit: |  | |||
§
George lives at the Charles Darwin Research Station
The giant Galapagos tortoise that became a conservation icon when it appeared he was the last of his kind is not so alone after all.
"Lonesome George" was thought to be the only survivor of a tortoise species native to the isle of Pinta.
Now, the journal Current Biology reports the discovery of a hybrid - the offspring from the union of a Pinta tortoise and another island species.
The "new" animal thus shares about half its genes in common with George.
Unfortunately for efforts to get George to reproduce, this hybrid tortoise, recently found on Isabela isle, is also a male.
Nonetheless, its discovery in a relatively small sample of tortoises raises fresh hope for the future of George's species (Geochelone abingdoni).
A more thorough sampling of the 2,000 tortoises living on Isabela could yet reveal a genetically pure Pinta tortoise, say the researchers.
Population revival?
But even if they did find one, getting George to mate with it could be an uphill struggle: he has a stubborn aversion to the opposite sex.
When George was placed in captivity at the Charles Darwin Research Station on the island of Santa Cruz, he was housed with two female tortoises from a species taken from Isabela.
After 35 years, he has failed to produce any offspring; though, admittedly, none of these tortoises has belonged to George's species.
Surprising find
The researchers, led by Michael Russello from the University of British Columbia Okanagan, Canada, took DNA samples from tortoises living around Wolf Volcano on Isabela.
Most of these tortoises are thought to belong to a distinct species called Geochelone becki.
The scientists analysed 89 of these tortoises and compared their genetic codes with those of other Galapagos tortoises that are held in a database.
§
'LONESOME GEORGE' SPECIES
Lonesome George Image: Thomas H Fritts
Size: 102cm across shell, 88kg in weight; not the biggest
Age: Not known exactly, but probably 60-90 years
Whalers and sealers destroyed the Pinta population
Invasive species have since disturbed the natural habitat
The database includes DNA from six G. abingdoni specimens held in museums, and Lonesome George.
Genetic analysis revealed that one of the Isabela animals was a first-generation hybrid between native tortoises from the islands of Isabela and Pinta.
"It's extraordinary. I, and everyone involved with George, never imagined that something like this could happen," said Henry Nicholls, who has written a biography of the octogenarian tortoise called Lonesome George: The Life and Loves of a Conservation Icon.
"It is surprising to find a hybrid on Isabela. It raises questions about how it got there," he told the BBC News website.
Whaling link
According to Dr Nicholls, none of the prevailing sea currents would be capable of carrying tortoises from Pinta to Isabela.
But, Dr Nicholls added, any project to search for a pure Pinta tortoise on Isabela, or other hybrids, would be expensive and time-consuming.
"The continuing saga surrounding the search for a mate has positioned Lonesome George as a potent conservation icon, not just for Galapagos, but worldwide," said Dr Russello.
Upwards of 50,000 people visit George each year at his home on the Charles Darwin Research Station.
The collapse of the giant tortoise population on Pinta is thought to have been due in large part to whaling activities in the Pacific during the 18th and 19th Centuries.
Sailors would preferentially take female animals to store as food on their ships - the females of the species were smaller and easier targets in lowland areas during the egg-laying season.
By the middle of the 20th Century, only male giant tortoises were left on Pinta. George is thought to have been born in the 1920s.
©Es genügt nicht, keine Gedanken zu haben, man muss auch unfähig sein, sie auszudrücken.
Warum hat Sveva Grigioni keinen Erfog bei ihm?
Ist Lonesome George ein Asozialer?
Lesen sie jetzt!
The New York Times
May 8, 2007
Findings
A Lonesome Tortoise, and a Search for a Mate
By JOHN TIERNEY
It is a truth universally acknowledged, at least among humans, that a giant tortoise in the possession of the last sperm of his species must be in want of a wife. But what if the tortoise prefers a different lifestyle?
When I met Lonesome George two decades ago, in his pen on the main island of the Galápagos, I had the usual impulse to fix up the world’s most famous bachelor. I chartered a fishing boat for a miserable trip out to Pinta Island, the wilderness 100 miles away where George had been discovered in 1971 living by himself.
As I fought my way through Pinta’s overgrown vines and cactus pads, fervently hoping to spot a female Pinta tortoise behind a lava rock or a thorn bush, I was already working on her name. Georgette seemed too derivative. I liked the local evolutionary allusion of Darwinia, but finally settled on less of a mouthful: Eve.
I didn’t find her, of course, so I went back to George’s pen to bid a sad farewell to him and his species. Then I penned a long — and quite moving, I thought — contemplation of the ethics of conservation, the destructiveness of man and the meaning of life.
Now it seems the obituary was premature. I was looking on the wrong island. Last week, after sampling the genes of a few tortoises on Isabela Island, biologists announced that there is probably at least one Pinta tortoise somewhere among the thousands of tortoises there. Next year the researchers hope to find a female to take back to George’s pen.
This is happy news for humanity, but not necessarily for George. We can shed a little of our collective guilt for nearly wiping out his species. George must deal with an identity crisis and performance anxiety.
What happens to his status as conservation icon — and his title as the rarest living creature? He could lose it all: his record, his name, his brand. Until now he’s been the main tourist draw at the Darwin Research Station, the prime example of what fund-raisers call charismatic megafauna.
Sans pathos, will he still be lucrative? His handlers hope that a new romance will inspire even more visitors and donations, but — and this is what really worries me — there might not be much romance when Eve arrives.
George is not what you would call a stud. When I visited him in 1985, he was thought to be a relatively young adult, maybe 50 years old, but he was already a confirmed bachelor. He hadn’t shown any interest in two females of a similar species placed in his pen. One had flipped over and drowned in the wading pool. The keepers weren’t positive that George had driven this tortoise to her death, but he definitely hadn’t been doing any Barry White serenades.
A few years later, in 1993, there was briefly a companion known as “Lonesome George’s girlfriend,” but she was not a tortoise. She was a 26-year-old graduate student in zoology from Switzerland named Sveva Grigioni.
By coating her hands in the genital secretions of female tortoises and gently stroking him, she managed to demonstrate a couple of times (in the course of several months’ work) that George was capable of an erection. But whereas her touch could induce other male tortoises to reach orgasm within a few minutes, with George she never managed to collect any sperm.
Her ministrations — or maybe it was the pheromones in the secretions — did seem to pique George’s interest in the female tortoises, as Ms. Grigioni reported to Henry Nicholls, the author of the definitive new biography, “Lonesome George: The Life and Loves of a Conservation Icon.” But George’s temporary interest did not translate into performance.
“He started to try copulation,” Ms. Grigioni said, “but it was like he didn’t really know how to.”
To be fair to George, he’s never been observed with a female of his race, Geochelone nigra abingdoni. (It has been traditionally classified a subspecies of giant tortoise, but many biologists now consider it a separate species.) After the news last week, I sought a prognosis from Ms. Grigioni on the prospects for abingdoni love.
“No one knows how George would react,” she replied tactfully. “The only way to know is to try. It is possible that he would recognize abingdoni pheromones, but there is no evidence that different species have different pheromones.” That didn’t sound too promising, but Ms. Grigioni tried to be optimistic. If a Pinta female arrives in George’s pen, she said, “nature will do the best she can.”
Bryan Milstead, the biologist who oversees the vertebrates at the Darwin Research Station, told me he had enough confidence in the abingdoni allure to bet me $20 on George’s going for it. I was tempted by the wager — my money would be on George retreating into a thornbush — but I couldn’t bring myself to bet in favor of extinction.
No, I’m hoping George will help us expiate the sins of our species, particularly the ancestors calling themselves scientists. The tortoise populations in the Galápagos were devastated first by hungry whalers and pirates, and then by museum collectors who were far more energetic than the sailors in scouring the islands for the few remaining animals. Until George was discovered, the last tortoises seen alive on Pinta were the ones captured and killed a century ago by an expedition from the California Academy of Science.
Now, though, it looks as if humans inadvertently helped save the species, too. The Pinta species was presumably transplanted to safety by a sailor, perhaps one who lightened his ship’s load by throwing tortoises overboard near Isabela. And without the Pinta DNA preserved in those museum specimens, biologists wouldn’t have enough genetic information from George alone to identify a Pinta tortoise on its new island.
If Eve is found, humans just have to do a little more work. George needs to be primed. Sending Ms. Grigioni back to work would be a start, and George could also learn by watching other males in action, as some biologists have proposed. Dr. Nicholls even raises the possibility of showing instructive videos to George — and if tortoise porn is what it takes, I say go for it.
But given George’s antisocial personality — he doesn’t like being around any other tortoises, male or female — we need to be considerate. If ultimately he’s just not that into Eve, then let Lonesome George be lonesome. We can’t expect him to save the species for our sake. It has to be good for him, too.
Copyright 2007 The New York Times Company
©Es genügt nicht, keine Gedanken zu haben, man muss auch unfähig sein, sie auszudrücken.