Archaea: The 'Dark Matter' of the Microbial World
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Archaea: The 'Dark Matter' of the Microbial World
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Re: Archaea: The 'Dark Matter' of the Microbial World
#2I love reading about these advances. Not my field, so it is all new to me in a pop-science way.
And it reaffirms my belief that humans (and all the other species, but I'm biased) are vastly weirder assemblages than it seems.
Re: Archaea: The 'Dark Matter' of the Microbial World
#3Is it known why there are no evolutionary intermediates between archea and eubacteria?
Nick Lane's book The Vital Questions has been highly recommended by the HN commentariat, and I think it more or less deserves its esteem. Lane gives an extensive theoretical analysis of the sequence of events wherein a eubacterium was engulfed by an archea, and the resulting endosymbiosis that was the beginning of complex (eukaryotic) life.
Apparently, the genomic evidence is strong that the original host was an archaeon an the original invader (later to become mitochondria) was a eubacterium. However, I don't think he discusses the origin of this divergence of eubacteria and archea, and why it persists so cleanly.
Re: Archaea: The 'Dark Matter' of the Microbial World
#4Is it known why there are no evolutionary intermediates between archea and eubacteria? Nick Lane's book The Vital Questions has been highly recommended by the HN commentariat, and I think it more or less deserves its esteem. Lane gives an extensive theoretical analysis of the sequence of events wherein a eubacterium was engulfed by an archea, and the resulting endosymbiosis that was the beginning of complex (eukaryot…
That's something I've always wondered about evolution in general. Why isn't there a continuum of species? For example, why are there chimpanzees and humans walking around as discrete species with nothing "in between". Seems unlikely that a few chimpanzees gave birth to human babies (or I guess some ancient human ancestor) one day, and then we just branched off and evolved separately leaving the rest of the chimpanzees behind. Why didn't the "better" DNA get fed back into the chimpanzee gene pool and the whole species evolve?
Obviously I know nothing about biology, but I'd love a high level explanation. It's the one thing that's always bothered me about evolution, because nobody ever explains it, and it seems like magic.
Re: Archaea: The 'Dark Matter' of the Microbial World
#5Is it known why there are no evolutionary intermediates between archea and eubacteria? Nick Lane's book The Vital Questions has been highly recommended by the HN commentariat, and I think it more or less deserves its esteem. Lane gives an extensive theoretical analysis of the sequence of events wherein a eubacterium was engulfed by an archea, and the resulting endosymbiosis that was the beginning of complex (eukaryot…
Lane has a good story and tells it nicely, but I don't think he represents the mainstream, and he conveniently throws all the evidence that doesn't agree with him under the rug.
Re: Archaea: The 'Dark Matter' of the Microbial World
#6Is it known why there are no evolutionary intermediates between archea and eubacteria? Nick Lane's book The Vital Questions has been highly recommended by the HN commentariat, and I think it more or less deserves its esteem. Lane gives an extensive theoretical analysis of the sequence of events wherein a eubacterium was engulfed by an archea, and the resulting endosymbiosis that was the beginning of complex (eukaryot…
That's something I've always wondered about evolution in general. Why isn't there a continuum of species? For example, why are there chimpanzees and humans walking around as discrete species with nothing "in between". Seems unlikely that a few chimpanzees gave birth to human babies (or I guess some ancient human ancestor) one day, and then we just branched off and evolved separately leaving the rest of the chimpanzee…
In general, geographic separation leads to speciation. It can be rivers (IIRC for example bonobos and chimpanzees live on different sides of the Congo river).
Another interesting example is I think seagulls along the arctic circle that are split in many species spread along an east-west axis. Most species can interbreed with their immediate neighbour, but not the neighbour of their neighbour (except at one point where the extreme populations meet and the immediate neighbours are not compatible either).
Re: Archaea: The 'Dark Matter' of the Microbial World
#7Is it known why there are no evolutionary intermediates between archea and eubacteria? Nick Lane's book The Vital Questions has been highly recommended by the HN commentariat, and I think it more or less deserves its esteem. Lane gives an extensive theoretical analysis of the sequence of events wherein a eubacterium was engulfed by an archea, and the resulting endosymbiosis that was the beginning of complex (eukaryot…
That's something I've always wondered about evolution in general. Why isn't there a continuum of species? For example, why are there chimpanzees and humans walking around as discrete species with nothing "in between". Seems unlikely that a few chimpanzees gave birth to human babies (or I guess some ancient human ancestor) one day, and then we just branched off and evolved separately leaving the rest of the chimpanzee…
Not an evolutionary biologist but my guess would be it has something to do with niches in an ecosystem and lack of evolutionary pressure to change in an environment in which you have reached some equilibrium.
Chimps for whatever reason were able to satisfy their biological imperatives within their given environment early on and have never needed to change. The human line, not so much.
I guess the way I see it is that some mutation in early humans (perhaps selected for by the environment) created a priority on brain development. I'm sure there were many dead-end branches along the way to us that we haven't noticed. We just look back and see a straight line from chimps to humans. Perspective is key here.
Of course, I could be completely wrong :)
Re: Archaea: The 'Dark Matter' of the Microbial World
#8Is it known why there are no evolutionary intermediates between archea and eubacteria? Nick Lane's book The Vital Questions has been highly recommended by the HN commentariat, and I think it more or less deserves its esteem. Lane gives an extensive theoretical analysis of the sequence of events wherein a eubacterium was engulfed by an archea, and the resulting endosymbiosis that was the beginning of complex (eukaryot…
That's something I've always wondered about evolution in general. Why isn't there a continuum of species? For example, why are there chimpanzees and humans walking around as discrete species with nothing "in between". Seems unlikely that a few chimpanzees gave birth to human babies (or I guess some ancient human ancestor) one day, and then we just branched off and evolved separately leaving the rest of the chimpanzee…
Arm-chair opinion, but there are - just that chimpanzees/humans are a particularly bad example 'cause it happened so long ago. Once you have a common ancestor species split off into different species those species, by definition, can't share mutations between each other. Separately, chimpanzees and humans are "different", not necessarily better than each other. I don't know enough about the evolutionary history to say why but superficially they're better at tree-living and we're better at Savannah-hunting. Two different environments, so sharing mutations probably wouldn't help much.
https://www.quora.com/If-evolution-is-true-then-why-are-ther... has some better ones.
Re: Archaea: The 'Dark Matter' of the Microbial World
#9Is it known why there are no evolutionary intermediates between archea and eubacteria? Nick Lane's book The Vital Questions has been highly recommended by the HN commentariat, and I think it more or less deserves its esteem. Lane gives an extensive theoretical analysis of the sequence of events wherein a eubacterium was engulfed by an archea, and the resulting endosymbiosis that was the beginning of complex (eukaryot…
That's something I've always wondered about evolution in general. Why isn't there a continuum of species? For example, why are there chimpanzees and humans walking around as discrete species with nothing "in between". Seems unlikely that a few chimpanzees gave birth to human babies (or I guess some ancient human ancestor) one day, and then we just branched off and evolved separately leaving the rest of the chimpanzee…
A species (at least in the mammal sense) by definition is discrete, as it refers to organisms capable of producing fertile offspring. This is why dog breeds (which exist on a continuum are not different species.
In terms of speciation (chimpanzees or their ancestors giving rise to humans) this usually occurs due to an event such as a seperation between groups of the same species. They are then subject to differing external pressures as they may live in isolation, and their genetics continue to diverge until they are so far apart that they can no longer procreate and have become a species.
Re: Archaea: The 'Dark Matter' of the Microbial World
#10Is it known why there are no evolutionary intermediates between archea and eubacteria? Nick Lane's book The Vital Questions has been highly recommended by the HN commentariat, and I think it more or less deserves its esteem. Lane gives an extensive theoretical analysis of the sequence of events wherein a eubacterium was engulfed by an archea, and the resulting endosymbiosis that was the beginning of complex (eukaryot…
That's something I've always wondered about evolution in general. Why isn't there a continuum of species? For example, why are there chimpanzees and humans walking around as discrete species with nothing "in between". Seems unlikely that a few chimpanzees gave birth to human babies (or I guess some ancient human ancestor) one day, and then we just branched off and evolved separately leaving the rest of the chimpanzee…
It didn't happen like that. Humans didn't branch from chimpanzees or the other way around.
At some point there was a common ancestor of both species. Its offsprings diverged into two species that continued evolving into the current humans and chimpanzees.