Gaps

A tale of two gaps:

1. Darién Gap

I learned of the Darién Gap, a roughly 60-mile gap in the Pan-American Highway in Panama, consisting of thick jungle that effectively separates North from South America, from TikTok a while back. It's been fun to see it pop up in popular culture thanks to Pluribus's latest episode "The Gap". The episode features one of the characters attempting to traverse the Gap to reach another character in the US.

2. Cat Gap

Today I learned about the Cat Gap — a ~7 million year gap where no "cat" fossils can be found. It's the story of the evolution and migration of animals and the intersection of climate change. Nimravidae, a family of cat-like carnivores that evolved in Eurasia (later migrating to North America), went extinct around 25 million years ago due to a combination of environmental changes and competition with "bear-dogs". Felidae started evolving into existence in Eurasia around the same time the Nimravids were going extinct. They ended the cat gap around 18.5 million years ago when they migrated over Beringia into North America.

It is wild to me that the earth evolved saber-toothed cats twice (Hoplophoneus for the Nimravids, Smilodon for the Felids).

Joining the Gaps

The time scales involved in the Cat Gap are staggering. Homo sapiens didn't appear until 300,000 years ago, meaning cats were missing from North America for about 25 times longer than humans have been on Earth. I was wondering why everything kept specifying North America when I was researching the cat gap, and ended up relearning (I think I knew this when I was younger and into paleontology) that the Isthmus of Panama didn't fully form until around 3 million years ago. Here's a fun, scientific site showing historic continental reconstruction.