3 ms·

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 c

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.

throwup238 8mo ago
> 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/ https://paleobiodb.org/ [2] https://timetree.org/ https://timetree.org/
cogman10 8mo ago
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.
- b112 8mo ago
  Greg Bear and his fancy pants radio says otherwise.
- usrnm 8mo ago
  > 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.
  - thaumasiotes 8mo ago
    But as soon as you've gone up from a chicken to the ancestor of a T-Rex, you do indeed find that T-Rexes are in the mix. They look different from what you'd normally think of as a T-Rex, in the same way that they also look different from what you'd normally think of as a chicken.
    - stevage 8mo ago
      I'm trying to imagine this creature that is only somewhat different looking from a t rex and a chicken. I get your meaning, just a funny phrasing.
- b00ty4breakfast 8mo ago
  turns out evolution is analog
- technothrasher 8mo ago
  This is because "species" is a taxonomical category that we invented, but that does not actually map cleanly to reality.
- vardump 8mo ago
  T-Rex nuggets. Mmmm...
andrewflnr 8mo ago
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 8mo ago
  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.
  - throwup238 8mo ago
    > how many fossils there might be at total on earth The number is both incalculable and vague - is a shark tooth enough to count as a fossil? How about diatoms and other microfossils? Diatomaceous earth alone contains around 10^6-10^7 frustules (the shell of a diatom) per gram. If you count them as fossils then the lower bound is 10^18 fossils per year just in diatomaceous earth production (the fossils are ancient but we produce nearly a million tons a year in diatomaceous earth).
    - hnlmorg 8mo ago
      If you have a fossil, and break it in half, then do you now have two fossils?
    - TurdF3rguson 8mo ago
      > is a shark tooth enough to count as a fossil No, but a fossil of a shark tooth counts as a fossil..
      - 8mo ago
jasonwatkinspdx 8mo ago
What you're looking for is the phylogenetic tree. Here's an explorable one: https://www.onezoom.org/ 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).

throwup238 8mo ago

> 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/ https://paleobiodb.org/ [2] https://timetree.org/ https://timetree.org/

cogman10 8mo ago

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.

b112 8mo ago
Greg Bear and his fancy pants radio says otherwise.
usrnm 8mo ago
> 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.
- thaumasiotes 8mo ago
  But as soon as you've gone up from a chicken to the ancestor of a T-Rex, you do indeed find that T-Rexes are in the mix. They look different from what you'd normally think of as a T-Rex, in the same way that they also look different from what you'd normally think of as a chicken.
  - stevage 8mo ago
    I'm trying to imagine this creature that is only somewhat different looking from a t rex and a chicken. I get your meaning, just a funny phrasing.
b00ty4breakfast 8mo ago
turns out evolution is analog
technothrasher 8mo ago
This is because "species" is a taxonomical category that we invented, but that does not actually map cleanly to reality.
vardump 8mo ago
T-Rex nuggets. Mmmm...

andrewflnr 8mo ago

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 8mo ago
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.
- throwup238 8mo ago
  > how many fossils there might be at total on earth The number is both incalculable and vague - is a shark tooth enough to count as a fossil? How about diatoms and other microfossils? Diatomaceous earth alone contains around 10^6-10^7 frustules (the shell of a diatom) per gram. If you count them as fossils then the lower bound is 10^18 fossils per year just in diatomaceous earth production (the fossils are ancient but we produce nearly a million tons a year in diatomaceous earth).
  - hnlmorg 8mo ago
    If you have a fossil, and break it in half, then do you now have two fossils?
  - TurdF3rguson 8mo ago
    > is a shark tooth enough to count as a fossil No, but a fossil of a shark tooth counts as a fossil..
    - 8mo ago

jasonwatkinspdx 8mo ago

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