CANBERRA, Sept. 16 (Xinhua) — A new genomic study reveals that despite a large population, koalas on South Australia’s Kangaroo Island carry a heavy genetic burden due to inbreeding.
Compared to mainland populations from Australia’s states of Victoria and Queensland, researchers found Kangaroo Island koalas have low genetic diversity and many long stretches of identical DNA passed down from both parents, a hallmark of inbreeding, according to a statement released Tuesday by Australia’s Flinders University.
Originating from fewer than two dozen koalas relocated from Victoria in the 1920s, this genetic bottleneck of Kangaroo Island increases risks of fertility and developmental problems, the statement said.
While the population has mostly resisted infectious diseases like chlamydia and koala retrovirus, its limited genetic diversity could leave it vulnerable to future threats such as other disease outbreaks and climate change, it said.
Scientists recommend genetic rescue, introducing koalas from mainland populations, to strengthen their resilience.
“Kangaroo Island has the potential to remain an important conservation refuge for koalas. But without genetic management, this ‘ark’ could become a trap,” said Flinders University Professor Luciano Beheregaray.
The study, published in Molecular Ecology, highlights the importance of ongoing genomic monitoring for species managed in isolation, said Beheregaray, the study’s senior author. ■