悉尼大学研究团队通过DNA分析发现，考拉物种的种群衰退发生在约10万年前，远早于人类到达澳大利亚的时间[1]。这一发现推翻了之前认为考拉种群危机仅源于人类活动的假设。研究人员首次计算了考拉的突变率（约为人类的一半），分析了457个考拉基因组，确定现存所有考拉都源自一个小型祖先种群[1]。
该古老种群在近60,000年前达到遗传瓶颈期，其衰退与最后一个冰河期的环保破坏时间相吻合[1]。在幸存下来后，这个种群重新繁衍并填充了澳大利亚东部[1]。到16,500至6,000年前间，东部幸存种群分裂成5个遗传不同的种群[1]。由Toby Kovacs领导的这项研究已发表于《分子生物学与进化》期刊[1]。自2022年以来，考拉在昆士兰州、新南威尔士州和澳大利亚首都领地已被列为濒危物种[1]。
Researchers from the University of Sydney have uncovered evidence that koalas experienced a severe population collapse approximately 100,000 years ago, far earlier than human arrival in Australia.[1] The study, led by Toby Kovacs, analyzed hundreds of koala genomes to establish that all living koalas descended from a small ancestral population that survived extreme climate changes and subsequently repopulated eastern Australia.[1] The research determined that koalas reached a genetic bottleneck around 60,000 years ago, well before humans arrived on the continent roughly 65,000 years ago, contradicting previous assumptions that population decline occurred only after human settlement.[1]
The investigation employed a novel approach by calculating the koala mutation rate—approximately half that of humans—for the first time, examining 457 koala genomes and four parent-offspring trio samples.[1] The population collapse coincided with environmental disruption caused by the last glacial period.[1] Between 16,500 and 6,000 years ago, the surviving eastern population fragmented into five genetically distinct groups.[1] The findings were published in the journal Molecular Biology and Evolution.[1]
Today, koalas face renewed conservation challenges, having been listed as endangered species in Queensland, New South Wales, and the Australian Capital Territory since 2022.[1]