Has the evolution of man been traced all the way back to abiogenesis?
How far back has human evolution been traced?
I looked at talkorigins.com but it only seems to trace man back our common ancestor with the chimp. It also has Homo sapiens neanderthalensis which I thought was a supposed to be a seperate branch.
If you mean what is the common ancestor of all life, then it’s probably some form of cyanobacteria, which are the most primitive organisms we currently know about.
Actually, I was looking for a timeline that went back form man to the beginnings of life. Does such a thing exist?
Depends on what you mean by “human evolution.”
Previous to our common ancestor with chimps (and for some time after) we were not “human.” So previous to that you are talking about ape evolution.
The general outlines of ape, primate, mammal, vertebrate, etc evolution are known, though there are gaps and uncertainties of varying sizes at different stages of the record.
No lineage has been traced back to “abiogenesis;” exactly how life originated is still controversial.
I don’t have one, but on Carl Sagan’s TV series “Cosmos,” he had an animated drawing showing various ancestors going back to “the beginning.” It was not too bad.
Picking “man” instead of any other vertibarte is somewhat arbitrary. I think it is safe to say that there is a pretty good overall sketch of the timeline, with lots of gaps that need to be filled in. Except for the abiogenisis part. I don’t think that’s been worked out to anyone’s satisfaction yet.
Have you been to a bookstore or library and looked under the “evolution” section or done a good google search? Should be a very easy thing to find.
Colibri:
Wow! That was like a mind meld. I didn’t see your post before I wrote mine. Honest!
Here’s a chunk of it:
This gives the branching of the tree from the earliest chordates to primates.
While it doesn’t go back to abiogenetic beginnings, The Tree of Life Project is a good site which will take you from the presumed common ancestor of Eubacteria, Eukaryotes, and Archaea all the way up to humans (or any other modern group).
Keep in mind, though, that phylogenies are constantly changing as new data are discovered and accounted for. I don’t know that we even have a complete phylogeny from “human-chimpanzee common ancestor” to “human”.
Thanks, DF, I knew I had seen that somewhere but couldn’t find it.
There are several problems with tracing our ancestry backwards.
A few years ago you could find general agreement that Homo led back to Australopithecus and Afarenesis and then to some ape and then primate. Today the new species and genera found in the past few years have this straightforward picture in a muddle. I doubt that there exists any true consensus about where these early fossils fit.
Fossil evidence for chimps and other apes is far harder to find than even that of human ancestors. With fewer fossils to work with, primate history is still very spotty.
So there is no good consensus on many important transitional areas, such as from primate to ape and ape to human or even whether it should be primate to both ape and human. (Using these terms loosely, of course. I’m not going to throw around terms like Hominoidea because only experts remember that it refers to apes and not humans.)
The details have always been contentious. I think the earlier posters all agree that it is the overall picture that is more or less agreed on, but that many of the details are up for debate.
Well, yes and no. There was a surprisingly high amount of consensus back around the days after Lucy was found. For a long time there had been a basic notion that you would only find one species of any animal exploiting an ecological niche at one time. The recent more ancient finds and the revelations of the number of human species living in the same area at the same time came as a huge surprise.
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I was emphasizing the difficulties of that debate. People forget that an incredibly high percentage of everything we have found in paleontology has come in the past few decades. Every issue of the journals plunks a new surprise down in front of us. We’re still in the midst of a furious argument about the relationship of birds and dinosaurs, for example, as well as a debate over whether the Cambrian explosion killed off many lines of descent or not.
The overall picture is much better known than ever before, but it is simply not true that a good line can be drawn from man backwards. Stephen Jay Gould used to emphasize that the tree of life is better described as a hedge. Which links lead from the top to the bottom are hard to follow.
EM:
I don’t know how closely you follow anthropolgy, but these guys can’t agree on what restraunt to meet at to have their arguments in. The contention has been there, maybe you just didn’t see it.
You are correct in that often new times fossils open more questions than they close.
Everybody in science argues. Hell, everybody in every field argues: economists, urban planners, literary critics, politicians.
This is a good thing, because the really bad ideas get argued out of existence and the arguments often create new hypotheses to be tested.
But in every field there are times of more consensus and times of less. Physics was in a state of high consensus in the late 1800s. Bright students were told to pick other fields because there was nothing left in physics to do. That came back to bite them in the ass in 1905, Einstein’s annus mirabilis.
And my contention is that human paleontology went through a period of relative consensus that is being ripped apart. I’ve been reading in it for 30 years and I see a real difference now. I love it when these times happen because they’re the exciting ones.