[magneticnorth]

This is an interesting way to think about plants and animals.

I'm finding it surprisingly hard to find sources for known age of species - is that information collected somewhere? Or is it something we often just don't know because of how sparse the fossil record is?

Wondering because of trying to look up the age of fern species I do eat (no cinnamon fern near me) and I can't find out.

[cogman10]

That's because when something becomes a new species is a surprisingly difficult and contentious debate in biology.

That's simply due to the nature of evolution. It's nearly impossible to look at one past generation of chicken to the next to figure out when the ancestor was no longer a chicken. Yet, go back far enough and you'll find T-Rexes in the mix.

Every generation is a new missing link. It's an extremely fuzzy process.

[usrnm]

> Yet, go back far enough and you'll find T-Rexes in the mix

Afaik, T-Rex was never a direct ancestor of modern birds, including chicken. T-Rex and birds are theropod dinosaurs, but it was a very large and diverse group of animals.

[technothrasher]

This is because "species" is a taxonomical category that we invented, but that does not actually map cleanly to reality.

[b112]

Greg Bear and his fancy pants radio says otherwise.

[b00ty4breakfast]

turns out evolution is analog

[vardump]

T-Rex nuggets. Mmmm...

[throwup238]

> I'm finding it surprisingly hard to find sources for known age of species - is that information collected somewhere? Or is it something we often just don't know because of how sparse the fossil record is?

It depends on what you mean by the age of the species. You can find the oldest known fossil occurrence at the Paleobiology Database [1] and the divergence time from molecular phylogenies via TimeTree [2].

[1] https://paleobiodb.org/

[2] https://timetree.org/

[andrewflnr]

It's pretty tricky to find out, yeah. And new evidence is coming in all the time. All the methods are either floors (a fossil at X date proves a species existed then, but lack of fossils found yet might be inconclusive) or estimates (like molecular clock techniques). Dating fossils themselves (or rather the rocks they're buried in) isn't always easy or possible. For more out-of-the-way species, if anyone has bothered trying to figure out the age it's likely buried in scientific sources that are tricky for novices to find or search, and maybe under debate.

[psychoslave]

That make wonder, how many fossils there might be at total on earth, and with current trend, how much time would humanity should continue to survive before those remaining will approach zero, if fossil formation as a known rate.

[jasonwatkinspdx]

What you're looking for is the phylogenetic tree. Here's an explorable one: https://www.onezoom.org/

Keep in mind that the further you go back the bigger the error bars on these date estimates, and that a tidy split is an abstraction over a more messy reality (example: we know the hominid groups interbred, giving people with european ancestry some fraction of neanderthal dna).