La Brea’s saber-toothed cats carried rare spinal tumors at an unexplained rate.

Researchers read the excess as inbreeding in a shrinking gene pool, the same spiral that lets a species collapse before its last member dies.

The tumors also reduced limb function, so the tar pits may have trapped disproportionately sick cats — a bias the study must still rule out.

Sources: Phys.org