Fossil hailed as Man's ancestor is 'not even close relative'

[Rrose Selavy]

Expect the creationists to use this :

Quote:

Darwinius masillae, the primitive primate that was unveiled to the world with huge fanfare and a Sir David Attenborough documentary in May, seems now to have been less of a missing link than an evolutionary dead end. Far from being an ancestor to humans, the lemur-like creature from 47 million years ago belongs to an entirely different branch of the primate family tree that has left no known descendants, research has indicated.

Quote:

“Documentaries are extremely important for public understanding of science, so scientists and the media need to work together to make sure that they have their facts straight, and that they are portraying a balanced view of the evidence. I think that the most responsible approach would be to create documentaries well after publication of scientific results.”

More here:
http://www.timesonline.co.uk/tol/new...cle6884359.ece

[Eos of the Eons]

I thought there was a just foot or ankle bone that was similar to our ancestors'. Lemurs are on a different branch to begin with.

[Roboramma]

Well, of course.

I mean, any particular fossil we find is much more likely to be a relatively close relative of our distant ancestor than the ancestor itself, and yet from our perspective it's quite difficult to tell those two cases apart.

That doesn't, of course, mean that we can't find out a great deal about that ancestor by studying to fossils of those close relatives.

Mind you, from the quote above it seems that the fossil may not have been particularly closely related to our ancestral species either, which is, I suppose, of some interest.

[Eos of the Eons]

I saw the documenary. It had a previous injury that contributed to its death in its young life. It's a very well preserved specimen, no matter if it is on this or that branch on the tree of evolution.

[Eyeron]

Was this Ardipithecus or something different?

[Eos of the Eons]

No, not ardie. Ardie was so NOT a lemur!!!

[CapelDodger]

Originally Posted by Eos of the Eons

I thought there was a just foot or ankle bone that was similar to our ancestors'. Lemurs are on a different branch to begin with.

Not to begin with. The point of lemur-like is that this takes us back close to the branching point on the primate line which separated lemurs from monkeys.

[jasonpatterson]

This is a great example of how the press can screw up a good story about a fossil find. It would be a very silly scientist who definitively claimed that Ida was a direct ancestor of humans.

What it represented, supposedly, was a creature that had existed at or very near the time when tarsiers and monkeys split and shared the characteristics of both but not one that 'evolved into' a group of monkeys in toto. You would expect that this animal had descendants that eventually went extinct, including the possibility of some that remained more primitive (that is, more like the animals at the branching point rather than later monkeys.) Reading the article, it appears that this characterization may have been mistaken and that it was an earlier division that created D. massilae and its sister species.

Here's a not fantastic example for comparison, the main problem being the time between the human/chimp split:
Imagine that civilized primates hadn't come to be for another 20 million years. When those creatures looked back at the fossil record, they might find a chimp skeleton. That skeleton wouldn't necessarily represent their ancestors, instead it would represent a creature that was in existence at the same time as their ancestors that shared many (but not necessarily all) of the characteristics that they had. The chimps would have had their own descendants who might have gone extinct entirely, but that would not have negated their importance in establishing a fossil record.

A video by AronRa that does a good job of pointing out some of the flaws with the media portrayal of Ida as well as going through the phylogenetics of the thing. He's got a lot of fun videos, for those with a little spare time on their hands.

YouTube Video This video is not hosted by the JREF. The JREF can not be held responsible for the suitability or legality of this material. By clicking the link below you agree to view content from an external website.

I AGREE

[Damien Evans]

Originally Posted by Eyeron

Was this Ardipithecus or something different?

Something different. Something 40 million years different.

[UnrepentantSinner]

I think it's a shame that the media whoring over Ida overplayed the "Missing Link" meme. Shouldn't any paleontologist worth his trowel know not to use that phrase even in casual conversation. She's still a wonderful and important find. It's a shame the hype overtook the facts.

[shadron]

The basic problem is (using AronRa's phylogenetic tree) is that at the time that Ida lived, it was one of a population of sibling creatures of the species Darwinius massilae, and surrounded by individuals of other tribes of similar species and genii, spread across the planet. Finally, these early primates living together were also surrounded through time by other species, some of which were already extinct and all of which would be at some point in the future (well before now). Somewhere in that population is the individual who underwent a mutation which changed him/her (from here I'll use the masculine form, but understand it could have been either) from whatever he was to whatever lemur-like creature eventually became Haplorhine (tarsiers and eventually monkeys). That individual and it's mate are uniquely on the direct ancestral line to all mankind; he is a Chromosome-X Adam (or perhaps a Mitochondrial Eve) in the sense that two of his/her direct descendants are the CXA and ME. Other species members may also be ancestral, but only by happenstance. Was that creature Ida? Chances are miniscule in the extreme that it was; Ida died young, for one thing. Was he a member of Ida's species, through time or space? That was what the scientist who described it would like to believe, strove to prove and caused a media uproar to promote, but detailed study by other scientists (according to the article in the OP) says, no, it was not. But was it in a closely related tribe? Yes, the characteristics show that Ida was quite close to the right combination of features to be THE ONE, just not as close as the describer would really have liked.

Similar arguments apply for Lucy and Ardy, though their species haven't yet been eliminated from the direct line. Making that determination requires lots of other fossils and study time, and luck. At one time (about the 1920s, I think) the Neaderthal species was thought to have been on the line of ancestry to modern Homo sap, but more study moved them off of it to their "cousins through homo erectus" status of today. Some anthropologists think they are actually an early homo sapiens subspecies; the determinations are that hard to make.

[shadron]

Originally Posted by Eyeron

Was this Ardipithecus or something different?

If you watch the AronRa video posted by jasonpatterson, he explains where on the primate phylogeny Ida resides. Ardi is on the line between the Great Apes and the Australopithecines, while Lucy is within one of the Australopithecine lines - maybe the one going towards homo, perhaps closely related (see above).

BTW, I've studied AronRa's tree, and I have some problems with the depiction. It sort of shows the tree with Gouldian spurts of species proliferation followed by stretches where teh chosen few move off to the next spurt. In reality it is more like a hairy snake, with branches taking off all along the central line (and the central line and any offshoot only differ through retrospective study), and the offshoot branches also branch and grow - for example, Chimps grow out of the third "bush" from the right (the Great Apes) and make it to the end, if you consider the right edge of the graph to be today in time, which is probably not an explicit property of the graph anyway. Is this sort of cladogram actually used in biology? It seems to me to be a bit deceptive.

[shadron]

Originally Posted by UnrepentantSinner

I think it's a shame that the media whoring over Ida overplayed the "Missing Link" meme. Shouldn't any paleontologist worth his trowel know not to use that phrase even in casual conversation. She's still a wonderful and important find. It's a shame the hype overtook the facts.

What is really astounding about her is that she is a superb fossil find for being 44 million years old. Fossils that fine are rare; witness teh condition of Ardi, for example. As cool and neat as that fossil is, Ida's is supremely complete and fine in detail. It rivals the fossils of the feathered dinosaurs and the Archaeopterx finds (much older, of course) in details.

[jasonpatterson]

Originally Posted by shadron

BTW, I've studied AronRa's tree, and I have some problems with the depiction.

...

Is this sort of cladogram actually used in biology? It seems to me to be a bit deceptive.

I think it's just so that the thing can be easily viewed and typed around on a video, honestly. It also shows a bunch of dead ends, which was a more important point in the earlier video where he used it.

This isn't how you'd expect to see it, it's normally the standard branching tree look, or sometimes a diagonally slanted look, iirc. Google cladogram for typical examples.

[Roboramma]

Originally Posted by shadron

Somewhere in that population is the individual who underwent a mutation which changed him/her (from here I'll use the masculine form, but understand it could have been either) from whatever he was to whatever lemur-like creature eventually became Haplorhine (tarsiers and eventually monkeys).

Evolution isn't something that happens like that: changes from one species to another take place over a very long time and through the course of a great number of mutations.

Moreover, many different individuals of any particular ancestral species, living at the same time, would have been direct ancestors to every member of the descendant species.

That's pretty easy to see, given that if say you have a population with members A, B, C, D, and many others, and:
1. A and B mate to produce E
2. C and D mate to produce F
3. E and F later mate to produce offspring.

A is ancestral to a later decendent species.

In this case, A, B, C, and D are all ancestral, in just the same way.

Moreover, while there may be some new mutation which arose in A which is adaptive, and passed on to its descendants, the same may be true of D as well.

Quote:

That individual and it's mate are uniquely on the direct ancestral line to all mankind;

I don't know where you arrive at that conclusion. Dawkins, in the Ancestor's Tale, says that if any individual in an ancestral population is an ancestor, something like 40% of the population is also an ancestor.
Why? Because they breed with each other.

[quote]he is a Chromosome-X Adam (or perhaps a Mitochondrial Eve) in the sense that two of his/her direct descendants are the CXA and ME.[quote]
Mitochondrial Eve (or Chormosome-X Adam) are not unique. Living at the same time as they were, there were many other individuals who were also the ancestors of all living humans. Moreover, there are also individuals who lived later than them that are ancestral to all modern humans, we just don't have the technology to tell exactly when or where.

Quote:

Other species members may also be ancestral, but only by happenstance.

I don't know what you mean by this sentence. You are either ancestral or not.

[godless dave]

Originally Posted by UnrepentantSinner

I think it's a shame that the media whoring over Ida overplayed the "Missing Link" meme. Shouldn't any paleontologist worth his trowel know not to use that phrase even in casual conversation.

I'm sure they do. But the press is going to use it anyway. If a scientist tells a reporter the sky is blue, you can count on the reporter, the reporter's editor, or a headline writer to distort the statement beyond all recognition.

[ponderingturtle]

Originally Posted by Eyeron

Was this Ardipithecus or something different?

No this was the greatest missing like ever that rewrote all the books on evolution 8 months ago, not last month. Totaly different primates.

Of course both seemed to be oversold to the public in a publicity rush in rather the same way.

[HeyLeroy]

I can't understand how creationists could try to use this as somehow 'debunking' evolution without admitting that evolution happens.

[Rrose Selavy]

Originally Posted by HeyLeroy

I can't understand how creationists could try to use this as somehow 'debunking' evolution without admitting that evolution happens.

Oh they'll try . They love to pick holes where evidence is missing eg Science "can't show us where we came from because it doesn't know", the controversies within the field, the small number of hoaxes etc etc

[HeyLeroy]

Oh, I know.

But then you explain, 'see, science is self-correcting. Can religion claim the same?'.

[ponderingturtle]

Originally Posted by HeyLeroy

Oh, I know.

But then you explain, 'see, science is self-correcting. Can religion claim the same?'.

Well sure see the reformation, but there are just so many fewer deaths when science self corrects.

[Rrose Selavy]

Originally Posted by HeyLeroy

Oh, I know.

But then you explain, 'see, science is self-correcting. Can religion claim the same?'.

But if you've ever seen Dawkins and others interviews with some of these Creationists/Evo Deniers then you'll know such explanations don't make a blind bit of difference because it doesn't provide the certainty they crave.

http://forums.randi.org/showthread.php?t=151131

[UnrepentantSinner]

Originally Posted by HeyLeroy

I can't understand how creationists could try to use this as somehow 'debunking' evolution without admitting that evolution happens.

Originally Posted by Rrose Selavy

Oh they'll try . They love to pick holes where evidence is missing eg Science "can't show us where we came from because it doesn't know", the controversies within the field, the small number of hoaxes etc etc

The cognative dissonance is almost musical for them.

Scientist: This 40 million year old fossil isn't a direct ancestor of humans, but is instead a member of evolutionary lineage X.

Creationist: See! That means evolution is a lie and the Earth is 6,000 years old!

[shadron]

Originally Posted by Roboramma

Evolution isn't something that happens like that: changes from one species to another take place over a very long time and through the course of a great number of mutations.
Moreover, while there may be some new mutation which arose in A which is adaptive, and passed on to its descendants, the same may be true of D as well.

OK, perhaps I'm being somewhat naive in my biology. But mutations happen in individuals, not species. I yield on the fact that many mutations go into the creation of a new species from an ancestoral one, and therefore that many or most of the members on the species are likely in total responsible for a species split. That invalidates a lot of what I wrote about inter-species relationships.

However, what I said about the intra-relationships of the species, and how fossils are interpreted in that light, I think are sound.

One has to realize that scientists, like many other occupations, are ego-driven. More so, research scientists have an occupation or not depending on the publish or perish paradigm. There are huge pressures to declare their own original findings as key to life-as-we-know-it as possible. A flaw in science culture, perhaps, but a self-correcting one, as egos die.

[Roboramma]

Originally Posted by shadron

OK, perhaps I'm being somewhat naive in my biology. But mutations happen in individuals, not species.

Yeah, definitely, I thought that was clear in my post as well, though it's not so clear in the quote you make, which puts two statements together which were separated by a great deal of text in the original post.

As is clear in my post, A and D are individuals of that species, not different species.

Quote:

I yield on the fact that many mutations go into the creation of a new species from an ancestoral one, and therefore that many or most of the members on the species are likely in total responsible for a species split. That invalidates a lot of what I wrote about inter-species relationships.

However, what I said about the intra-relationships of the species, and how fossils are interpreted in that light, I think are sound.

Oh, definitely, we agree there. The chances of any fossil we find being an example of an ancestral species rather than a member of a species that was closely related to that ancestral species is slim, and more so the further back we go.