Humans Didn't evolve from Apes - How Do We Know?

[KuriousOrange]

Humans Didn't Evolve From Apes - How Do We Know?

I apologize in advance if this is a stupid question, but I've only just developed an interest in science/biology/evolution after a misspent youth and am playing catch up!

When looking at fossils of early hominids such as Australopithecus afarensis, they are said to have some chimp-like features and some human ones(human hips, valgus knee, but chimp size brain etc). My question is, how do we know that the chimp "like" features aren't exactly chimp features, and that humans evolved directly from chimpanzees? Is this to do with the small difference in our genomes/DNA, or is it something else?

IDiots/Creationists say how can we evolve from things that still exist, but that to me is nonsense - there are still wolves as well as domestic dogs, so why is it unlikely/impossible that we evolved from one of the apes that still exist?

 

[Eric D]

I apologize in advance if this is a stupid question, but I've only just developed an interest in science/biology/evolution after a misspent youth and am playing catch up!

When looking at fossils of early hominids such as Australopithecus afarensis, they are said to have some chimp-like features and some human ones(human hips, valgus knee, but chimp size brain etc). My question is, how do we know that the chimp "like" features aren't exactly chimp features, and that humans evolved directly from chimpanzees? Is this to do with the small difference in our genomes/DNA, or is it something else?

IDiots/Creationists say how can we evolve from things that still exist, but that to me is nonsense - there are still wolves as well as domestic dogs, so why is it unlikely/impossible that we evolved from one of the apes that still exist?

We didn't evolve from apes that still exist. Humans and modern apes share a common ancestor that existed 4 to 6 million years ago. So if any creationist is using this argument, you can easily refute him.

However, you are right that organisms can have evolved from organisms that still exist. Read up on ring species sometime.

 

[KuriousOrange]

We didn't evolve from apes that still exist. Humans and modern apes share a common ancestor that existed 4 to 6 million years ago.

I know, but how do we know? That's my question. How do we know that "Lucy" for ex. wasn't part way between an actual chimpanzee and an early homo?

Edit: I won't be getting into any arguments with religious fanatics, it's time badly spent when I have so much to learn.

 

[Beerina]

We evolved from something more apelike -- the closest ancestor to us and our nearest relative, the chimp, was neither human nor chimp.

That is an interesting question, though. Do they have a skeleton of such a creature? What was it like? Was it simpler than both a human (brainwise, anyway) and simpler than a chimp's brain? In other words, did the chimp's brain increase in size after the split much, if any?


In a sense, the whole "we evolved from apes" thing is overblown as an objection point by creationists -- as well as the defense against it by evolutionary scientists. This creature way back when, if it existed today, would be put in the primate house at the zoo right next to chimps, gorillas, and orangutans.


Just because we didn't evolve from an existing great ape doesn't mean what we did come from wouldn't count at one. And that creationists get so stuck on the idea it must have been a still-existing one shows how far out to left field their thinking, or lack thereof, is.

 

[pakeha]

Welcome to the forum, KuriousOrange!
Here's a link that leads to a lot of information.
http://humanorigins.si.edu/

Have fun!

 

[jiggeryqua]

I know, but how do we know? That's my question.

With luck and a following wind, you might eventually get an answer to it. Meanwhile, welcome to JREF and the procession of cookie cutter creed responses to keywords, regardless of your actual question...

 

[KuriousOrange]

We evolved from something more apelike -- the closest ancestor to us and our nearest relative, the chimp, was neither human nor chimp.

So this ancestor would have the homo genus and Australopithecus branching off in one way and Chimpanzees in another - how do we know chimps aren't our direct ancestor? how have we determined this "cousin" relationship with chimps and ruled them out as being a direct antecedent?

 

[Eric D]

I know, but how do we know? That's my question. How do we know that "Lucy" for ex. wasn't part way between an actual chimpanzee and an early homo?

Because Lucy didn't evolve from a chimpanzee so there's no way it can be between a chimpanzee and a human.

 

[Marduk]

So this ancestor would have the homo genus and Australopithecus branching off in one way and Chimpanzees in another - how do we know chimps aren't our direct ancestor? how have we determined this "cousin" relationship with chimps and ruled them out as being a direct antecedent?

Because the chimps of today didn't exist back then, they evolved at the same time that we evolved from an ancestor who we both share

Humanity left the forests and our differences are a result of having to survive in a non arboreal habitat

this should make things clear

(A) Pan troglodytes, chimpanzee, modern
(B) Australopithecus africanus, STS 5, 2.6 My
(C) Australopithecus africanus, STS 71, 2.5 My
(D) Homo habilis, KNM-ER 1813, 1.9 My
(E) Homo habilis, OH24, 1.8 My
(F) Homo rudolfensis, KNM-ER 1470, 1.8 My
(G) Homo erectus, Dmanisi cranium D2700, 1.75 My
(H) Homo ergaster (early H. erectus), KNM-ER 3733, 1.75 My
(I) Homo heidelbergensis, "Rhodesia man," 300,000 - 125,000 y
(J) Homo sapiens neanderthalensis, La Ferrassie 1, 70,000 y
(K) Homo sapiens neanderthalensis, La Chappelle-aux-Saints, 60,000 y
(L) Homo sapiens neanderthalensis, Le Moustier, 45,000 y
(M) Homo sapiens sapiens, Cro-Magnon I, 30,000 y
(N) Homo sapiens sapiens, modern

chimps who's habitat has remained unchanged for millions of years have evolved very little, you can see a chimp skull compared to 2.6 million year old Australopithecus africanus in pictures a and b

 

[KuriousOrange]

O.K, thanks Marduk. How do we know the date (i'm not worried about the exact day ) of the split between the chimp/human branches? Is it purely from the fossil record?

 

[KuriousOrange]

Welcome to the forum, KuriousOrange!
Here's a link that leads to a lot of information.
(can't post links yet)

Have fun!

Bookmarked,many thanks.

 

[Marduk]

O.K, thanks Marduk. How do we know the date (i'm not worried about the exact day ) of the split between the chimp/human branches? Is it purely from the fossil record?

Although the hominoid fossil record is far from complete, and the evidence is often fragmentary, there is enough to give a good outline of the evolutionary history of humans. The time of the split between humans and other living hominoids used to be thought to have occurred 15 to 20 million years ago. Some species occurring within that time period, such as Ramapithecus, used to be considered as hominins, and possible ancestors of humans. Later fossil finds indicated that Ramapithecus was more closely related to the orangutan, and new biochemical evidence indicated that the last common ancestor of humans and other hominins occurred between 5 and 10 million years ago, and probably in the lower end of that range

.
http://en.wikipedia.org/wiki/Ape
wiki is far more eloquent than me
it must have been a friday, as you get older you soon notice how often break ups always happen just before the weekend

 

[MRC_Hans]

We don't have fossils of the common ancestor. The fossil record, especially of land mammals, is generally quite patchy (fossilization is rare for land creatures).

The most certain way to map lineages is through mitochondria DNA. This DNA is inherited in the female lineage of mammals and since it does not influence genotype, it changes by mutation at a fairly steady rate. So by following the M DNA we can obtain very good evidence of the sequence of lineage splits and the time scale of them.

Hans

 

[Marduk]

We don't have fossils of the common ancestor.

thats only because they don't know which species it was

I always fancied this guy
something about it just screams "Daddy"
http://en.wikipedia.org/wiki/Proconsul_(primate)

 

[KuriousOrange]

something about it just screams "Daddy"

Lol

 

[pakeha]

O.K, thanks Marduk. How do we know the date (i'm not worried about the exact day ) of the split between the chimp/human branches? Is it purely from the fossil record?

You've had some excellent answers, KuriousOrange and here's another take on that question from
http://humanorigins.si.edu/evidence/genetics

DNA also shows that our species and chimpanzees diverged from a common ancestor species that lived between 8 and 6 million years ago. The last common ancestor of monkeys and apes lived about 25 million years ago.

 

[Dancing David]

Um probably the best answer is that we don't have lot of direct evidence for the exact nature of the line that leads to homo sapiens sapiens.

We have a lot of random data points widely scattered in the fossil record, the best data comes from genomes.

It suggests very strongly that chimps and apes evolved from a common ancestor.

 

[KuriousOrange]

So in theory the common ancestor could've evolved into something in it's own right (or stayed relatively the same ) and lived alongside us?

Also, if our DNA is 98/99% same as the chimpanzee's, then would that be the same in the living common ancestor if we did find one? Or does that depend on how much it has changed/evolved?

 

[MRC_Hans]

thats only because they don't know which species it was

I always fancied this guy
something about it just screams "Daddy"
http://en.wikipedia.org/wiki/Proconsul_(primate)

Yes, that is possible. Or he is part of the common lineage. When fossils get old enough, we loose DNA info (although the technology for retrieving it is steadily improving), and we are left with skeletal morpology. For this reason we may never conclusively identify the common ancestor, even if we might find it.

Hans

 

[MRC_Hans]

So in theory the common ancestor could've evolved into something in it's own right (or stayed relatively the same ) and lived alongside us?

Also, if our DNA is 98/99% same as the chimpanzee's, then would that be the same in the living common ancestor if we did find one? Or does that depend on how much it has changed/evolved?

The common ancestor also evolved into two species of chimpanzees, which are still (so far ) with us.

It also evolved into several species of homoids, none of which are with us today.

In theory, an undiscovered species that share the common ancestor might exist somewhere, but the chances are slim. If you will, Bigfoot and Yeti could be candidates for this, but real evidence of their existence is, at best, very vague.

We would expect the common ancestor's DNA to be between us and the chimp, but in theory there could have been some convergent evolution. Statistically, it is unlikely, however.

Hans