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
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