Wednesday, November 30, 2005

Evidence of Common Descent between Man and Chimp



(H=human, C=chimp, G=Gorilla, O=orangutan)

Long long ago, in a laboratory far far away, scientists figured out that chimpanzees have 24 chromosomes in their sperms and eggs, whereas humans only have 23. Therefore, these great scientists theorized that two of our chromosomes might have fused together sometime in the recent past (aka million years ago.). Their theory made 3 predictions:

1) One of our chromosomes would look like two of the chimp chromosomes stuck together.
2) This same chromosome would have an extra sequence in it that looked like a centromere. Centromeres are the things in the middle that microtubules grab onto to divide a pair of chromosomes during mitosis.
3) It would also have telomeres (ends) but in the middle - and they would be in reverse order. Sort of like this:

ENDchromosomestuffDNEENDchromosomestuffDNE

See the "DNEEND" in the middle? That's what two telomeres would look like if two chromosomes were stuck together.

--From an excellent post by scigirl on IIDB.



As you might have guessed, all three predictions have been verified. While, as always, it's impossible to prove that an all-powerful being didn't create the evidence to trick us, the reasonable explanation is that humans and chimps share a common ancestor.

20 comments:

Hayim said...

> the reasonable explanation is that humans and chimps share a common ancestor.

Ah, well, when the evidence is too strong we may need to re-examine our understanding of the Chumash.

"And God said : let us make man ..."

Why the plural form, asks Rashi ? This question has intrigued generations of commentators, who all came up with forced answers. Who was God talking to, himself ? Angels ? Give us a break, rabbi !

But now ! The new darwinishe pshat (in Darwin al HaTorah, soon to be included in the next edition of mikraot gedolot) : God was actually talking to monkeys : "evolve !".

Yes sir. :)

Random said...

Ahem. That should be chromosome *pairs* - humans actually have 46 chromosomes and apes 48. I'm sure it's just a typo though:-)

CyberKitten said...

JA said: it's impossible to prove that an all-powerful being didn't create the evidence to trick us, the reasonable explanation is that humans and chimps share a common ancestor.

If God is a trickster... we can never know anything & it would be pointless to try. We have to assume that reality is as it appears to be - unless we have VERY strong evidence to the contrary, otherwise any kind of invesigation of the Universe is impossible.

Laura said...

Adam and Eve were chimps! That explains why they didn't have conflicting feelings about screwing eachother to procreate the species! :p

Jewish Atheist said...

Ahem. That should be chromosome *pairs* - humans actually have 46 chromosomes and apes 48. I'm sure it's just a typo though:-)

The sperm and egg cells only get one chromosome from each pair, so they have 23 and 24. All the other cells in the body have 46 or 48. :)

Orthoprax said...

JA,

Ha! I was just thinking about posting on this exact topic since I was reading up recently on Robertsonian translocations. I guess you (and scigirl) beat me to it. ;-)

Shlomo said...

Until we obtain DNA samples from this alleged "Creator", we cannot be sure that we are, in fact, "b'tzelem-b'demus Elokim" (in its image).

Orthoprax said...

JA,

"All the other cells in the body have 46 or 48. :)"

'Cept funny ones like RBCs. :-)

Jewish Atheist said...

Orthoprax,

Sorry for pre-empting your thunder. ;) Good point on the red blood cells. I should have said "all the other cells that have chromosomes have 46 or 48. :)

SL Aronovitz,

Too funny.

Random said...

Blast - serves me right for being too eager to comment on an error to read the fine print. I'll slink away shamefacedly now:-)

asher said...

Since we share so much with ape ancestors you really wonder why chimps haven't gotten very far in the 3 billion years they've been around. In fact, no apelike creature acts anything like humans at all. They don't cooperate, they don't experiment, they don't create anything, they only mate when they are in "heat", they don't question why they are here, and more importantly, they don't seem to be bothered that they share chromosomes with humans.

Looking forward to seeing the new version of King Kong. Aren't you?

I forgot who said this....Humans have taught apes to understand almost 50 human words. I've yet to see a single ape teach a human to speak ape talk..

Orthoprax said...

Asher,

"Since we share so much with ape ancestors you really wonder why chimps haven't gotten very far in the 3 billion years they've been around. In fact, no apelike creature acts anything like humans at all."

Apes are very well adapted to their respective natural environments. They're still around which means that they've gotten just "as far" as humans have.

"They don't cooperate, they don't experiment, they don't create anything..."

Wrong on all counts. Apes are cooperative, curious tool users.

"they only mate when they are in "heat","

Well, yes..not sure about the judgment call on that though.

"they don't question why they are here,..."

That may not be the worst thing to do. One could argue that constant endless worrying on insoluble questions is wasteful and pointless.

Jack's Shack said...

Asher,

Orthorpax is right, chimps are very similar to us.

Sadie Lou said...

Sorry if this sounds stupid but if you look at the animal kingdom a lot of animals share humanistic traits. I mean, you can humanize a lot of animal behavior. So doesn't it stand to reason that humans are the only ones that project ourselves on other species?
We look at apes and we see common characteristics.
We look at dolphins and see common characteristics.
We look at dogs and we use words like "loyal" and "obedient" and "brave" to explain their personality. This doesn't mean we are descendents from all these animals. So why the ape?
I'll admit that apes act like us the most and have similar physical traits as well but to apes sit around and speculate on how much they are like us or us like them?
It's just weird to think of how much more advanced we are than any other creation on the planet and yet--we still compair ourselves to the animals.
Sorry for the long winded-ness

Jewish Atheist said...

It's just weird to think of how much more advanced we are than any other creation on the planet and yet--we still compair ourselves to the animals.

We are certainly more advanced mentally than any other animal, but make no mistake -- we are animals. It's not simply because of our behavioral similarities with other primates that we believe we share a common ancestor, but also amazing DNA similarities, developmental similarities, structural similarities, and fossil evidence indicating many animals which appear to bridge the gap between human and ape.

Sadie Lou, you might be interested in this person's essay about Christian evolution: http://www.theistic-evolution.com/theisticevolution.html

Sadie Lou said...

I bookmarked that site. I really liked it so far. I much more reading to do but I loved this statement:
Next to these great beliefs, a biological theory seems pretty unimportant. That impression is correct. Do I "Believe in Evolution" like I believe in the Resurrection of Jesus Christ? Absolutely not! I accept the Theory of Evolution like I use the Quadratic Formula; they are both useful for a certain class of problems that I sometimes have to solve. I certainly do not place my eternal life and soul in the care of a scientific theory or a mathematical formula. I am no atheist. I place my entire being in the hands of God Almighty through his Son, Jesus Christ.

I reject the idea that evolution and Christianity are always and must be in opposition to each other. I reject the notion that if the scientific theory of evolution is true, then Christianity must be false. I reject the idea that people who accept evolution must be atheists. I reject the idea that the scientific theory of evolution fundamentally denies the idea of God the Creator. I reject the idea that evolution and Christian faith are inevitably in conflict with each other and cannot be reconciled.


Thanks for the link.

Orthoprax said...

Sadie,

"We look at dogs and we use words like "loyal" and "obedient" and "brave" to explain their personality. This doesn't mean we are descendents from all these animals. So why the ape?"

It's not just in terms of indeterminate flexible things like emotions and behavior, but based on quantifiable things like physiology, anatomy, and biochemistry.

Shlomo said...

I look at human behavior and sometimes wonder if I am really part of or descended from humans. I see how we manipulate and exploit each other, and a host of others who make justifications for that evil. I see the cruelties that humans impose on each other and Nature. I see humanity lacking foresight. I see people who prefer war over peace and killing over cooperation. I think to myself "Could I really be descended or related to these vile creatures?"

Unfortunately, my biochemistry and physiology says I am indeed one of that species. I am doomed!

Sadie Lou said...

It's not just in terms of indeterminate flexible things like emotions and behavior, but based on quantifiable things like physiology, anatomy, and biochemistry.

I said physical as well as all the other things I listed.

Orthoprax said...

Sadie,

You did, but it didn't seem like you understood the depths to which the physical characteristics are homologous. It's more than just having a pair of hands, their very proteins which do essentially everything in their bodies are very much like ours.