St Kilda's Shrinking Sheep

[AtlanticFlamethrower]

Over the 25-year period of their study the Soay sheep on the island of Hirta in the Outer Hebrides had shrunk by about 2cm (0.8in) or 81g (2.9oz) per year, amounting to about 5 per cent of their body mass.

The scientists attributed the change to short-term changes in climate rather than to the long-term pressures of natural selection, which would favour a larger - not a smaller - body size.

Previously the smallest lambs would have perished in the cold conditions of early spring. But shorter, milder winters and warmer springtimes mean that more small lambs survive and pass their "small" genes on to their offspring, according to the study, which is published today in the journal Science.

Source: Latest threat from global warming: shrinking sheep

Counter source:

the process and condition of the reduction in size of large animals - almost always mammals- when their gene pool is limited to a very small environment, primarily islands.

This effect has made itself manifest many times throughout natural history, including dinosaurs, like Europasaurus, and modern animals such as elephants.

There are several proposed explanations for the mechanism which produces such dwarfism, which are often considered likely to be co-contributing factors, including an evolved gene-encoded response to environmental stress, as well as a selective process where only the smaller of the animals trapped on the island survive, as food declines to a borderline level.

The smaller animals need fewer resources, and so are more likely to get past the break-point where population decline allows food sources to replenish enough for the survivors to flourish.

[laserguy]

By that reckoning,shouldn't Australia's sheep be the size of hamsters :huh: ?

[AtlanticFlamethrower]

By that reckoning,shouldn't Australia's sheep be the size of hamsters :huh: ?

Don't tell that to an Aussie when he's coming in to bowl!

[Chris Knight]

Previously the smallest lambs would have perished in the cold conditions of early spring. But shorter, milder winters and warmer springtimes mean that more small lambs survive and pass their "small" genes on to their offspring, according to the study, which is published today in the journal Science.

The Journal "Science" seems to have given up Darwinism in favour of Lamarckism, if this is the case. Whatever next: Creationism?

[Admiral_Bobski]

Well, we all know what happens to wooly jumpers when you put them in the tumble drier, don't we?

CB

[Pingo]

Sounds to me like these "scientists" didn't have a clue so needed to pin the change on something, which given the fashionable XFactor-ish desire for any old excuse decided to go for climate change.

The XFactor Sheep.

Suppose it's nothing to do with dominance among the male sheep who wanted smaller female sheep. Never mind investigating anything at all, it just has to be climate change because the scientists concerned can't be arsed getting out of their office in London to do some proper science.