Faced with an epidemic of cancer that cuts their lives short, Tasmanian devils have begun breeding at younger ages, according to researchers at the University of Tasmania in Australia.
“We could be seeing evolution occurring before our eyes. Watch this space!” says zoologist Menna Jones of the university.
Tasmanian devils live on the island of Tasmania, south of Australia. They weigh 20 to 30 pounds and were named devils by early European settlers because the furry black marsupials produce a fierce screech and can be bad-tempered.
Since 1996 a contagious form of cancer called devil facial tumor disease has been infecting these animals and is invariably fatal, causing death between the ages of 2 and 3.
In the past devils would live five to six years, breeding at ages two, three and four, but with the new disease, even females who breed at two might not live long enough to rear their first litter.
Jones, who has been studying the animals' life cycles since before the outbreak, noted that there has been a 16-fold increase in breeding at age one. She reports her findings in this week's edition of Proceedings of the National Academy of Sciences.
“What we are suggesting in this paper is that there is likely to be strong selection for rapid evolution” toward early maturity, Jones said in an interview via e-mail.
“It was an exciting discovery,” she added.
The disease could cause the devils to become extinct in 25 years or so, she said, but this change to younger breeding may slow population decline and reduce the chance of them disappearing. Meantime, the search for a vaccine continues.