Deadly domino effect of extinction proved by boffins
One predator snuffs it and others follow in its wake
Boffins have proved a theory for the first time that the extinction of one animal has a domino effect on other species.
The researchers from the University of Exeter found that when a carnivore dies out, other predatory species could soon follow.
The bioboffins used parasitic wasps to prove the ripple-effect one extinction can cause.
They bred two species of parasitic wasps and two types of aphids - little plant-sapping bugs - placing the different insects into tanks in different combinations.
In the tanks that only held one kind of wasp, the second went extinct within a few generations, but if both types of insect were kept in a tank, they thrived.
The second extinction was caused by the food running out. When the wasps that ate one of the aphids or greenflies weren't around, that bug grew in numbers, threatening the other little flies survival and therefore the second species' food.
"Our experiment provides the first proof of something that biologists have argued for a long time: predators can have indirect effects on each other, to the extent that when one species is lost, the loss of these indirect effects can lead to further extinctions," head boffin Dr Frank van Veen said in a canned statement.
"Although our study focused on insects, the principle would be the same for predators in any ecosystem, ranging from big cats on the African plains to fish in our seas."
Van Veen, who works at the university's Centre for Ecology and Conservation, said the study showed that trying to save just one kind of animal in an ecosystem could end up hurting it and other predators in the area.
"A ‘single species’ approach to conservation can be ineffective and even counter-productive," he argued. "For example, protecting cod could lead to increased fishing pressure on other predatory fish which then, by the mechanism we have demonstrated here, could lead to further negative effects on the cod."
The study was published in the Royal Society journal Biology Letters. ®
"In the tanks that only held one kind of wasp, the second went extinct within a few generations"
That makes no sense at all.
I follow the thrust of the argument: that if one predator goes extinct, its prey thrives, outcompetes another prey species, second prey species either goes extinct or is at least severely reduced in numbers, predator that preys on now extinct prey species goes extinct.
But I don't think the predator that wasn't in the tank in the first place would take "a few generations" to disappear.
Re: "Publicity driven science seems to have all the simple answers"
I doubt very much that the science was driven by a desire for publicity. Most likely they just worked out a way of making this (scientifically) interesting and useful experiment* amenable to public consumption, and when the Reg saw the press release they rewrote it a bit and stuck it on here. Please do not confuse the press release/media report with the actual science.
As for its simplicity: very possibly you could get this result in a computer simulation, or even predict it with a mathematical description, but it's very nice to see it in a system involving real biology as well. And stripping back the system to the bare minimum enables you to discover general principles that are utterly obscured in something as complicated as a real-world ecosystem. Extracting simple answers from a confusing mess is /good/ science[*], after all, the utility of statements like "it's all too complicated, we haven't got a sodding clue what's going on!" is somewhat limited.
[*] and of course scientists also make a point of understanding the limitations of those simple answers.
... in the tanks that only held one kind of wasp, the second went extinct ...
Ann Elk also had a pretty good theory on brontosauruses, which made as much sense as the species not being in the tank getting extinct
> In the tanks that only held one kind of wasp, the second went extinct within a few generations
Is this some kind of weird quantum entanglement ?
Where we get some kind of schroedinger wasp ?
you wont know if the second species is exting until you look in the box to see if the first species still lives ?
... puzzled ...