Why in News? A new scientific study has found that a koala population in Victoria, Australia has regained much of its lost genetic variation thanks to a rapid increase in numbers. The research, published in the journal Science, suggests that population growth can help endangered species overcome inbreeding.
Background
Koalas (Phascolarctos cinereus) are tree‑dwelling marsupials native to Australia. They feed exclusively on eucalyptus leaves and spend up to 18 hours a day sleeping. Heavy hunting for their fur in the early 1900s reduced koala numbers drastically. Small groups were moved to predator‑free islands, where their populations slowly recovered. In recent decades, habitat loss and disease have again threatened the species.
Findings of the study
- Researchers analysed genetic data from over 400 koalas across eastern Australia and reconstructed their demographic history. They found that the Victorian population fell to about 500 individuals a century ago but has since expanded to nearly half a million.
- As numbers grew, mating among descendants produced new combinations of genes and mutations. This “reshuffling” increased genetic diversity despite the population’s narrow origins, reducing harmful traits like tooth and testicle deformities.
- The study shows that rapid population growth can quickly mitigate inbreeding, providing hope for other endangered species. However, scientists caution that genetic recovery alone may not be enough; habitat protection and disease management remain vital.
About koalas
- Koalas are marsupials, meaning females carry their young (joeys) in pouches for around six months.
- They have thick grey fur, large fluffy ears and strong claws for gripping tree branches. Adults weigh between 4 and 15 kilograms and measure 60–85 centimetres in length.
- Koalas are listed as “Vulnerable” on the IUCN Red List. Major threats include habitat destruction, bushfires, the chlamydia disease and climate change.
This research provides a hopeful example of how conservation measures can help species rebound not only in number but also in genetic health.