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Humans are more closely related than we commonly think

scientificamerican.com

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Re: Humans are more closely related than we commonly think

#91

Post by acjohnson55 »

genghizkhan wrote: post #56
coldtea wrote: post #55

Earlier quoted context omitted.

> Go back far enough and there is a set of individuals who were alive at a particular point in time that completely cover that forward tree. So like Adam and Eve? :-)

Adam: https://en.wikipedia.org/wiki/Y-chromosomal_Adam Eve: https://en.wikipedia.org/wiki/Mitochondrial_Eve

I'm trying to square those articles, which put Y-chromasomal Adam and Mitochondrial Eve >100kya with the Identical Ancestor Point, which is only 5000-15000ya.

I guess it's kind of like the difference between a permutation and a combination.

Re: Humans are more closely related than we commonly think

#92

Post by TheCoelacanth »

danaris wrote: post #87
zuminator wrote: post #62

Earlier quoted context omitted.

The article is saying that every person bears some relation to each other, even among distant groups. No further back than 3500 years ago existed a person who was a common ancestor to every currently living human being.

Nnnno; 3500 years ago, there were already clearly-separated groups of humans on different continents. Perhaps you're off by a 0 or two...?

No, there were fuzzily-separated groups of humans on different continents. There was still some interbreeding across continents.

The Americas may have been clearly separated for a while, but they have done so much interbreeding with people from other continents since 1492, that the common ancestor is more recent than that.

Re: Humans are more closely related than we commonly think

#93

Post by levosmetalo »

goto11 wrote: post #46
piokoch wrote: post #40

Earlier quoted context omitted.

Hmm, I was really surprised about the part on woman creation, as I've never read such version (in Polish), but, indeed this https://www.biblegateway.com/passage/?search=Genesis+2&versi... (very) strange translation mentions woman to be taken from man's rib. This translation https://www.biblegateway.com/passage/?search=Genesis%201&ver... looks much better "So God created mankind in his own image, in the image of God h…

You are looking at two different verses. NIV have basically the same text for Genesis 2:21: https://www.biblegateway.com/passage/?search=Genesis+2%3A21&... > So the Lord God caused the man to fall into a deep sleep; and while he was sleeping, he took one of the man’s ribs and then closed up the place with flesh.

He took a rib from the left or from the right side? The truth would be easy to prove by counting how many ribs a man has on which side. If it's true, one side would have one rib more.

If the number of ribs is the same, then it's either that God didn't create a woman from man's rib, or he took two ribs, one from each side, and created two women.

Re: Humans are more closely related than we commonly think

#94

Post by golf5 »

jlawson wrote: post #19
themgt wrote: post #3

While this article's content isn't exactly wrong, the Wikipedia on "Identical ancestors point" gives some important context for what's actually being asserted: All living people share exactly the same set of ancestors from this point back, all the way to the very first single-celled organism. However, people will vary widely in how much ancestry and genes they inherit from each ancestor, which will cause them to have…

Another important point here is that genes don't divide infinitely, so that if you go back some distance, you start finding ancestors from whom you actually didn't get any DNA. The book Who We Are and How We Got Here talks about this. When DNA recombines at conception, it only snips and stitches in a fairly limited number of places. It doesn't 'mix' finely like paint. It's more like taking two short pamphlets of ~25…

Contradicting that narrative is probably a career ender.

Re: Humans are more closely related than we commonly think

#95

Post by jacobr1 »

levosmetalo wrote: post #93
goto11 wrote: post #46

Earlier quoted context omitted.

You are looking at two different verses. NIV have basically the same text for Genesis 2:21: https://www.biblegateway.com/passage/?search=Genesis+2%3A21&... > So the Lord God caused the man to fall into a deep sleep; and while he was sleeping, he took one of the man’s ribs and then closed up the place with flesh.

He took a rib from the left or from the right side? The truth would be easy to prove by counting how many ribs a man has on which side. If it's true, one side would have one rib more. If the number of ribs is the same, then it's either that God didn't create a woman from man's rib, or he took two ribs, one from each side, and created two women.

Or the loss of rib isn't a form lamarckian inheritance.

Re: Humans are more closely related than we commonly think

#96

Post by rsynnott »

nobodyandproud wrote: post #88
hnracer wrote: post #52

Earlier quoted context omitted.

Korean people are genetically shorter than other races. Do you dispute that this would give them a profound disadvantage in basketball, all else equal? The narrative of all races being functionally the same phenotypically is prima facie absurd as even the most simplistic armchair observation reveals. Anyone who denies that Korean people have a genetic distadvantage in basketball must be acting in bad faith, and if th…

The height difference owes a lot to nutrition and the long-term living standards of the different countries. I bet the height difference in Koreans between the different generations alive today is quite different from one another. As for Olympics 100 years ago. Are you for real? Most of Asia was under the thumb of Imperialism. They weren’t exactly positioned to “send their best”. How many African nations participated…

> I bet the height difference in Koreans between the different generations alive today is quite different from one another.

Also quite different between the Koreas. While the average height in both has increased significantly since the Japanese occupation, it has done so significantly faster in South Korea (as you'd expect, given the economic difference).

Re: Humans are more closely related than we commonly think

#97

Post by bsanr2 »

jlawson wrote: post #19
themgt wrote: post #3

While this article's content isn't exactly wrong, the Wikipedia on "Identical ancestors point" gives some important context for what's actually being asserted: All living people share exactly the same set of ancestors from this point back, all the way to the very first single-celled organism. However, people will vary widely in how much ancestry and genes they inherit from each ancestor, which will cause them to have…

Another important point here is that genes don't divide infinitely, so that if you go back some distance, you start finding ancestors from whom you actually didn't get any DNA. The book Who We Are and How We Got Here talks about this. When DNA recombines at conception, it only snips and stitches in a fairly limited number of places. It doesn't 'mix' finely like paint. It's more like taking two short pamphlets of ~25…

"This means that these infintesimal mixings have even less impact than you'd think. A modern Japanese person could have a European ancestor who traveled to Asia a thousand years ago, but have zero genes from that ancestor. Which means that while that European is technically an 'ancestor', this is just a bit of historical trivia, it means literally nothing about that Japanese person's biology."

It also means that a modern Japanese person has thousands of "Japanese" ancestors from whom they received zero genes. Of course, this is a bit of misdirection, as the genes that one receives are not unique, but drawn from a pool of possible genotypes common to humanity. The matter of how closely we resemble each other is not one purely of ancestry, but of the size of that pool - our overall genetic similarity. From what I gather, it's not an exceptionally large pool. I may not have gotten whatever gene controls the formation of the human prefrontal cortex from the same nth ancestor as you, but I got it all the same.

Also, where does dominance play into this, I wonder?

Re: Humans are more closely related than we commonly think

#98

Post by bzbarsky »

acjohnson55 wrote: post #91
genghizkhan wrote: post #56

Earlier quoted context omitted.

Adam: https://en.wikipedia.org/wiki/Y-chromosomal_Adam Eve: https://en.wikipedia.org/wiki/Mitochondrial_Eve

I'm trying to square those articles, which put Y-chromasomal Adam and Mitochondrial Eve >100kya with the Identical Ancestor Point, which is only 5000-15000ya. I guess it's kind of like the difference between a permutation and a combination.

This is talked about in the article too: You do not have genes from all your ancestors, because any given person only contributes half their genes to their children. So you have to go much further back to find a point when someone's genes would be present in all modern-day humans.

In particular, if you have a male ancestor at the Identical Ancestor Point but the lineage from them to you passes through a woman at any point in the family tree, you would not get that male ancestor's Y-chromosome via that line of descent.

Or put yet another way, if you are male, you have 2^N (possibly overlapping) ancestors N generations back, but only _1_ ancestor N generations back that contributed your Y-chromosome. Comparing to a different male, the chance that you share Y-chromosomes is naively something like 1/P where P is the size of the male population at the time, while the chance that you share your ancestor sets is a much more complicated calculation, and the article claims it's ~1.

Re: Humans are more closely related than we commonly think

#99

Post by bsanr2 »

simonh wrote: post #38
JPLeRouzic wrote: post #21

Earlier quoted context omitted.

>> The genetic evolutionary difference between distinct groups like Europeans, sub-Saharan Africans, ... is something like 70,000 years of divergent evolution with very very minimal gene flow between the groups. Any citation?

The 'recent dispersal' started some 70-50,00 years ago, reaching Europe about 40,000 years ago. https://en.wikipedia.org/wiki/Early_human_migrations#Homo_sa... Europeans have pretty low levels of sub-saharan genetic markers, with some remnant markets in southern Europe dating to the late Roman era, diminishing substantially as you move north. https://en.wikipedia.org/wiki/African_admixture_in_Europe

Low admixture, sure. And similarity of genetypes?

Re: Humans are more closely related than we commonly think

#100

Post by sjburt »

acjohnson55 wrote: post #91
genghizkhan wrote: post #56

Earlier quoted context omitted.

Adam: https://en.wikipedia.org/wiki/Y-chromosomal_Adam Eve: https://en.wikipedia.org/wiki/Mitochondrial_Eve

I'm trying to square those articles, which put Y-chromasomal Adam and Mitochondrial Eve >100kya with the Identical Ancestor Point, which is only 5000-15000ya. I guess it's kind of like the difference between a permutation and a combination.

Adam and Eve are along the male (or female) line, whereas the common ancestor could be anywhere in your family tree. So 10 generations back you only have a single male line ancestor but 1024 ancestors total.
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