Dark and Light-coated Soay rams
Reuters
Wild sheep on a remote Scottish island are shrinking, and
scientists blame global warming.
Soay sheep are on average 5 percent smaller than 25 years ago,
an indication climate change can have a rapid effect on natural
populations and a sign of possible more widespread changes in
future, researchers said on Thursday.
The island of Hirta's shrinking sheep are notable because
classical evolutionary theory suggests they should actually get
bigger over time, since larger animals tend to be more likely to
survive and reproduce than smaller ones.
But now, due to climate change, grass for food is available for
more of the year, making survival conditions less challenging, so
even slow-growing sheep have a chance of making it and producing
smaller offspring in turn.
"It's probably a bit too early to predict that we'll have
Chihuahuas running around herding pygmy sheep in say 100 years
time," Tim Coulson of Imperial College London, who led the
study
published in the journal Science, told reporters.
"In our future work we are going to try and draw these strands
together to provide a more comprehensive understanding of the way
that climate change is influencing genetic change."
(Reporting by Ben Hirschler; Editing by Matthew Jones)