Traces of inbreeding have been found in the bones of sabre-toothed tigers

Researchers suggest that, shortly before their extinction, the population of these predators had declined significantly. As a result, the animals may have increasingly interbred with close relatives. However, the scientists themselves emphasise that this is, as yet, merely a scientific hypothesis that has yet to be tested.

What the scientists found

The researchers examined 3,722 vertebrae belonging to at least 849 adult sabre-toothed tigers.

It turned out that many of the animals had abnormally formed spines:

• 32 vertebrae were underdeveloped;
• 48 were fused together;
• 226 had an unusual structure.

Such abnormalities are not uncommon in themselves, but their high prevalence within a single population led scientists to consider possible genetic issues.

Some of the animals may have had tumours

An even more unusual finding was three vertebrae with characteristic changes in bone tissue.

According to the researchers, such changes could have been caused by slow-growing tumours of the spinal nerves. These cause severe pain and, in severe cases, can impair limb function.

If the animals did indeed have such tumours, it would have been much more difficult for them to hunt.

Why this is linked to inbreeding

When animal populations decline sharply, it becomes more difficult to find an unrelated mate. As a result, the likelihood of inbreeding increases.

This can lead to the accumulation of harmful genetic changes, an increase in the number of congenital defects and a deterioration in the health of the offspring.

Similar problems are observed today in some small and isolated populations of wild animals.

The study’s authors emphasise that inbreeding was most likely not the cause of the sabre-toothed tiger’s extinction.

In their view, the population initially declined due to other factors — climate change, the disappearance of prey, or other causes. Genetic problems may have arisen later and further weakened the animals.

Furthermore, the link between the anomalies found and inbreeding has not yet been proven. This would require the analysis of ancient DNA.

Why this is important

The study shows that endangered species may face not only food shortages or climate change, but also the consequences of declining numbers.

When animal numbers become too low, genetic diversity declines and the risk of hereditary diseases increases. This is precisely why maintaining large, stable populations remains one of the key requirements for the conservation of rare species.

Source

Journal: Frontiers in Veterinary Science (2026).