4 ms·

> both occurred multiple times on earth Citation?

by zabzonk 6y ago

vmception 6y ago
Any Biology & Ecology 101 book from the last decade and a half.
- zabzonk 6y ago
  Provide a link to one.
mannerheim 6y ago
There are several kingdoms with multicellular life. Plants, animals, most fungi, some protists (many protists are more closely related to animals, fungi, or plants than they are to each other for that matter). See: https://en.wikipedia.org/wiki/Eukaryote#Five_supergroups https://en.wikipedia.org/wiki/Eukaryote#Five_supergroups Note e.g. that animals and fungi are closely related on this diagram, but there are unicellular fungi (notably yeast). I would guess that this means the common ancestor between animals and fungi would have been unicellular. At any rate, both are far from plants, and other protist species unrelated to all of these are multicellular. Endosymbiosis is generally accepted to also have occurred with chloroplasts. I believe there are also contemporary observed cases of protists consuming photosynthetic organisms and becoming immobile.
andrewflnr 6y ago
Check out the abstract of this paper: https://www.pnas.org/content/99/18/11558 https://www.pnas.org/content/99/18/11558 It takes for granted not only the long-established belief that chloroplasts were once free-living blue-green bacteria, but a number of eukaryote-within-eukaryote endosymbioses. As for multi-cellular life, plants, animals, fungi, and {brown,red,green} algae independently developed it: https://en.wikipedia.org/wiki/Multicellular_organism https://en.wikipedia.org/wiki/Multicellular_organism This seems like a good article that describes the multicellularity problem in general, several interesting borderline cases, experiments in inducing the evolution of simple multicellularity (in one case, just by introducing predators into a culture), and ideas as to why it took as long as it did: https://www.sciencemag.org/news/2018/06/momentous-transition-multicellular-life-may-not-have-been-so-hard-after-all https://www.sciencemag.org/news/2018/06/momentous-transition...

> both occurred multiple times on earth Citation?

vmception 6y ago

Any Biology & Ecology 101 book from the last decade and a half.

zabzonk 6y ago
Provide a link to one.

mannerheim 6y ago

There are several kingdoms with multicellular life. Plants, animals, most fungi, some protists (many protists are more closely related to animals, fungi, or plants than they are to each other for that matter). See: https://en.wikipedia.org/wiki/Eukaryote#Five_supergroups https://en.wikipedia.org/wiki/Eukaryote#Five_supergroups Note e.g. that animals and fungi are closely related on this diagram, but there are unicellular fungi (notably yeast). I would guess that this means the common ancestor between animals and fungi would have been unicellular. At any rate, both are far from plants, and other protist species unrelated to all of these are multicellular. Endosymbiosis is generally accepted to also have occurred with chloroplasts. I believe there are also contemporary observed cases of protists consuming photosynthetic organisms and becoming immobile.

andrewflnr 6y ago

Check out the abstract of this paper: https://www.pnas.org/content/99/18/11558 https://www.pnas.org/content/99/18/11558 It takes for granted not only the long-established belief that chloroplasts were once free-living blue-green bacteria, but a number of eukaryote-within-eukaryote endosymbioses. As for multi-cellular life, plants, animals, fungi, and {brown,red,green} algae independently developed it: https://en.wikipedia.org/wiki/Multicellular_organism https://en.wikipedia.org/wiki/Multicellular_organism This seems like a good article that describes the multicellularity problem in general, several interesting borderline cases, experiments in inducing the evolution of simple multicellularity (in one case, just by introducing predators into a culture), and ideas as to why it took as long as it did: https://www.sciencemag.org/news/2018/06/momentous-transition-multicellular-life-may-not-have-been-so-hard-after-all https://www.sciencemag.org/news/2018/06/momentous-transition...