The University of Illinois and University of Puerto Rico have completely sequenced the mitochondrial genome for the Hispaniolan solenodon, filling in the last major branch of placental mammals on the tree of life.
The study, published in Mitochondrial DNA, confirmed that the venomous mammal diverged from all other living mammals 78 million years ago, long before an asteroid wiped out the dinosaurs.
“It’s just impressive it’s survived this long,” said co-first author Adam Brandt, a postdoctoral researcher at Illinois. “It survived the asteroid; it survived human colonization and the rats and mice humans brought with them that wiped out the solenodon’s closest relatives.”
That is why it is endangered now, researchers say.
While the solenodon is venomous and resembles a “giant rat with Freddy Krueger claws” (according to Roca), it evolved in the absence of carnivores. Today, it is threatened by cats and dogs introduced by humans as well as habitat loss. More.
Talk about stasis! If the solenodon ends up surviving only under human protection, it will be one of the few instances of a very ancient life form that (almost) went extinct for a reason we can clearly identify.
See also: Stasis: Life goes on but evolution does not happen
New poisonous mammal? Better read the fine print
Lazarus species: Animal we thought were extinct
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