Earliest Primate Placed With Dinosaurs

Quirk writes "National Geographic has a piece suggesting the earliest primates were contemporaries of dinosaurs. The article is an endorsement for the evolutionary dating system using molecular-clock studies. The earliest primates according to the current fossil record suggests a common ancestor about 55 million years ago after the great dinosaur die-off. Relying on biology and mathematics the new study suggests a small, nocturnal creature of the tropical forests was the earliest primate. The research viewed fewer differences in genetic codes as an indicator that the more recently two species parted evolutionary company, and, math equations were used to flesh out the tree and to predict when and for how long species may have lived. So, really, a Rachel Welch lookalike in a skimpy fur bikini may have actually fled a rampaging T-Rex."

Comments

duh

[tps12]

Yes, the earliest primates are commonly known as "cavemen," and it is clear that they lived with, ate, and rode dinosaurs for farmwork and warfare. It is a little known fact that monkeys, apes, and even some mammals are also primates, technically related to both humans and cavemen (also known as "early man"). Dinosaurs were either birds or reptiles, or even occaisionally amphibians, but never primates, unfortunately.

Re:duh

[Peter Trepan]

These "cavemen" were unearthed from the surrounding "Bedrock", an archeological site scientists described as "a place right out of history."

Re:duh

[PD]

Wow! I already had you marked down as an enemy. Looks like this isn't just a bad day. You're an asshole ALL the time.

Re:duh

[PD]

Bitch

The origin of the species

[realgone]

Tavaré's team suggested that the earliest primates might have been small, nocturnal creatures...

A-ha! Coders!

No

[4of12]

So, really, a Rachel Welch lookalike in a skimpy fur bikini may have actually fled a rampaging T-Rex."

Uh-huh.

I beg to differ.

When I saw Planet of the Apes for the first time and saw Raquel Welch in her fur bikini my first thought was NOT

Recognize Creature = rodent
DNA match = 0.982

rather I thought her DNA was spectacularly different from that of myself and most people I knew, and in very important ways.

Re:No

[4of12]

You're right. I stand corrected.

It was Linda Harrison, not Raquel Welch, that was in the original Planet of the Apes.

The actress' name is...

[WalletBoy]

So, really, a Rachel Welch lookalike in a skimpy fur bikini may have actually fled a rampaging T-Rex."

The actress' name is Raquel Welch, not Rachel Welch. There's a site here where you can look up names if you're not sure on the spelling.

Humanoids go way further than that. . .

[ahfoo]

The mammal-like reptiles had a skull structure very much like modern mammals and lived not only with the dinosaurs, but hundreds of millions of years before them. These creatures are considered the ancestors of all modern mammals and they would probably have had a facial structure similar to modern mammals given that they had a ridge of bone above the eye sockets where the jaw muscles from their jaw --similar in shape and function to a mammalian jaw, as opposed to a reptilian jaw-- connected to the skull.

Sorry, no.

[juju2112]

So, really, a Rachel Welch lookalike in a skimpy fur bikini may have actually fled a rampaging T-Rex."

Not unless you think Rachel Welch looks a lot like a Tarsier

Mitochondrial DNA Concordance

[juju2112]

It sounds like the technique they used was Mitochondrial DNA Concordance

Mitochondrial DNA is different from nuclear DNA. With the help of mathematics, can be used to determine degrees of relatedness between species, and when two species diverged from their common ancestor. My Human Evolution professor explained this technique in class just yesterday. It was used as evidence that Neanderthals contributed no DNA to the Homo Sapien gene pool.

Incidentally, talkorgins.org is a great site for this kinda stuff.

Re:Mitochondrial DNA Concordance

[juju2112]

Another good link related to this:

http://www.talkorigins.org/faqs/homs/mitoeve.html

Re:Mitochondrial DNA Concordance

[juju2112]

mtDNA is different from nuclear DNA. There is a lot more of it per cell, so it's easier to find. It's also shorter - about 16,000 base pairs.

You're right about how fossils form, that's what I was taught as well. But apparently some DNA can remain if the specimen is not too old. Neanderthals were here just 30,000 years ago. I mean, we're not taking 65 million years here.

From talk origins:

After death, DNA starts degrading immediately. It is thought that under the most favorable conditions, some DNA fragments can survive for as long as 50,000 to 100,000 years. The Feldhofer Neandertal fossil, thought to be between 30,000 and 100,000 years old, was therefore pushing the limits for this kind of work. However initial testing of the fossil showed good preservation of amino acids, indicating that it might contain recoverable mtDNA.

Polymerase Chain Reaction (PCR) is a technique which can be used to create many copies of an initially small number of molecules. The researchers used PCR to amplify and extract many short strands of mtDNA from the Neandertal sample. By overlapping these, they were able to generate a sequence of 379 bases apparently from the Neandertal individual. To protect against errors and contamination, each base was extracted in at least two separate amplifications.

Also, they can compare mtDNA with a bunch of humans living today, calculate the differences, and then use math to figure out when the common ancestor of all of them lived. So if you want to find out when the common ancestor of two being lived, you don't actually need the mtDNA of the common ancestor.

Uhh, Tarsier

[zenyu]

She does look kinda cute, too short for my tastes though ;)

Interesting, but...

[the phantom]

First off, this is probably the knee-jerk reaction in defense of everything that I have been taught (ala Kuhn's The Structure of Scientific Revolution -- old guard fights to defend their theories while those damn punk children walk all over them -- funny that, I should be one o' those punk kids!) however, without seeing a technical article explaining how these conclusions were reached, I have a couple of questions:

How did they arrive at this date of 81.5 million years ago? They discuss using DNA and mathematical estimates of age. Both are highly theoretical, and I could run the same experiment, using only slightly different numbers and come up with something completely different. In the case of DNA (probably Mitochondrial DNA, not nuclear DNA), we do not know the rate of genetic drift -- it is variable for all we know. So, assumptions based on MtDNA are on tenuious ground. In the case of their equations, what were these equations? What were the base assuptions used to create them?

It is interesting to think that primates have evolved much earlier than the fossil record indicates, but it is very hard to believe without any real evidence. As the article itself states "'Of course, this is all speculation,' Tavaré acknowledged. 'We have not found any fossils in that bin yet.'"

Re:Interesting, but...

[Lars Arvestad]

I think it is healthy to demand proper evidence for all scientific claims! And I am quite certain the the authors, Tavare in particular given your own quote, are well aware of this and do not see their conclusions as written in stone. Also, it is interesting to notice that the authors are probably from what you call the "old guard". I know Tavare is, and his co-authors being spread all over the world in distinguished departments suggests the same for them.

As to their method, please see my other post. It is certainly public, and it will be scrutinized by other researchers for sure. You can visit your closest research library and look it up in Nature. In short, they do not use DNA for their analysis, only the fossil record.

Cheers,

Re:something to think about

[juju2112]

Exactly. An early primate might have looked something like this.

an early primate sketch and an evolutionary tree

[juju2112]

The Field Museum in Chicago, where this study was done, has an nice press release on this here.

They also released a sketch of what the earliest common ancestor for primates might have looked like, and a nice evolutionary tree which might put some of this into perspective for some of you.

Re:something to think about

[piecewise]

Well there's an awful lot of "could have"'s in there. The problem is that science has proof of so much, whereas religion, as its called, requires faith. Not to say that faith makes it untrue.

I wonder though... those that don't believe in Jesus, and practice drastically different religions.. to "us," they are going to hell. To them, what if we are going to their equivelant of hell FOR believing in Jesus? (I'm not saying we ALL do, I'm just speaking generally here.)

Chinese people don't believe in Jesus or "God." Are they going to hell? And if so, does that mean that, here on earth, they represent satan and we should either convert or destroy them? I like the Chinese people I know.

In the end, my point is that science and religion don't always mix. But they just might one day... because remember one thing:

Science and religion are exact opposites in the aspect that religion is pre-defined, whereas science started at 0 and has progressed through time. In the end, they just might meet up... I know when I look up into the sky and the stars, I have a much better sense of "heaven" that pure science OR pure religion can prove to me with texts and theories and accounts. It's just THERE... those stars. And for me, that's where science+religion make perfect sense and symmetry.

Amoukar!

[Rui del-Negro]

According to some scholars, we all descend from Ron Perlman.

RMN
~~~

Their method in a nutshell

[Lars Arvestad]

I have browsed the Nature paper by Tavare et al that is the basis for the National Geographic piece, and have a good idea about what they are actually doing.

Contrary to what people here at /. are expecting, the authors do not use molecular data in their method (although they have compared their findings with studies using DNA). Instead, they have used a model for how species appears and goes extinct, modelled how the fossil record has been sampled, and then compared with known fossil data.

The speciation/extinction model says that species go extinct and split up in subspecies at certain rates. The fossil findings model is simply that the number of found fossils from a certain period of time is binomially distributed.

Data summarizing the number of primate fossils from different time periods was collected, and a starting point for the primate lineage that best explained the fossil record was computed.

In essence, if the starting point is too early, the method disqualifies it because we have not seen enough fossils, and if it is too late, it is disqualified because we have seen too many.

I could add that Simon Tavare is a well-respected statistician with solid experience in, for example, population genetics. (I don't recognize the other author names.) It would have been nice to see comments from other researchers about their assumptions, but I did not see anything on the Nature site and have not had the time to research this more closely.

Cheers,