5 ms·

Our Neanderthal Complex

25 points by pmcpinto 12y ago

carsongross 12y ago
Given that europeans consist of up to 5% or more Neanderthal genetic stock, it's increasingly untenable to look at the Neanderthal as some sort of "other". They is us.
- kolev 12y ago
  I'm European and I have about 2.4% (I know this thanks to 23andMe).
- pcrh 12y ago
  5% isn't all that small either, it's 1/20. On a population basis it would be the equivalent of 1/20 people being pure Neanderthal.
  - mcv 12y ago
    No, that's really not the same thing. The Neanderthal genes have been quite dilluted over the millennia. Everybody has a tiny bit, and nobody has a lot.
    - pcrh 12y ago
      It depends on what you are considering. If 1/20 people of a population were 100% Neanderthal, and the rest 0% Neanderthal, over millenia, and assuming random mixing, the whole population would tend towards what it is today. So we are potentially heirs of a population where Neanderthals mixed with non-Neanderthals in a (very) broadly similar ratio as Europeans versus non-Europeans in the US today. I only intend this to illustrate that 5% is not as trivial a number as people often imply, and that it potentially derives from a population of Neanderthals and non-Neanderthals mixing in quite a "modern" fashion. I would add to this that one interesting fact concerning human-neanderthal genetics is the absence of Neanderthal mitochondria in modern humans. This may mean that Neanderthal women couldn't bear human-Neanderthal offspring, and if they could have, the proportion of Neanderthal DNA in modern humans might have been twice as high as it currently is.
- duaneb 12y ago
  Well then why bother discussing pre-homo sapien speciation at all? EDIT: To put it another way, you wouldn't compare a modern european to a neanderthal and call them part of the same people. The neanderthals still had large differences with other populations.
  - carsongross 12y ago
    I'm not saying it isn't worth discussing pre-homo sapien speciation at all, I'm saying that the vague idea that the Neanderthals are some "other thing" from our genetic heritage (as compared with, say, Cro-Magnon) has become less tenable as genetic analysis has advanced. The story of Neanderthal is, for many of us, partly the story of us. Genetically, some of us have the equivalent of a great-great grandparent that was Neanderthal.
squozzer 12y ago
I believe in evolution but one question has always bothered me - when a social animal is born with a mutation (even one that is unquestionably superior), wouldn't the other members of e group kill or shun her? This question may sound far-fetched unless you're non-white or a ginger.
- todd8 12y ago
  No Most mutations wouldn't be obvious. They might affect metabolism or some enzymatic pathway. (Isn't it curious that Junior likes cow's milk?) These seem unlikely to be discriminated against. Even mutations affecting visible features might be gradual and require the accumulation of many mutations over generations and generations to become pronounced. (Height, skull size, dentition) Some features might be due to a single mutation and could be pronounced and obvious in new members of a group. Red hair might be one of these mutations, and perhaps some red headed children were spurned or killed or discriminated against by their group. But this wouldn't easily eliminate red hair. It is caused by a recessive gene so carriers of a single gene won't be redheads themselves. If two non-redheaded carriers of the gene have 4 children on average three will carry the red hair gene but only one will have red hair because they carry two of the genes. I find red hair attractive, and apparently so did our ancestors: red hair was not eliminated from the gene pool. Curiously, humans have evolved to retain juvenile features. This neoteny, as it is called, has resulted in smaller jaws, flatter faces, hairless bodies, larger eyes, and other features. Selection for these traits may be due to our instinctive desire to care for infants. Likewise mutations in the other direction, smaller head to body ratio, etc., could very well have suffered from negative selection pressures as you have raised in your question. I think these speculations are interesting and the answers are not obvious. Why, for example, has a trait such as mental illness, clearly having a negative impact on survival, not been eliminated? Is it just so tricky to get a brain assembled into a mind that there are inevitable difficulties? Or is it caused by interactions with viruses during development that are evolving in competition with us? What about nearsightedness? I wouldn't have been a very good hunter of distant game. Why hasn't myopia been eliminated as a trait? Is it because as I age I can still read without reading glasses? Were there elderly nearsighted arrowhead makers, able to do close work despite age related presbyopia, trading their skillfully made arrowheads for food? One additional observation. Your question mentions non-whiteness, suggesting that more pigmented skin is a mutation. It appears that it is just the reverse. Human evolution started in Africa where pigmentation would have been important because of the more intense sunlight. Lack of pigmentation would be a disadvantageous mutation. So the more accurate question is why would anyone even have light skin? The answer I've heard is that for humans groups that had migrated out of Africa to latitudes that had weaker sunshine, lighter skin allowed for better absorption of the weaker sunlight for the production of vitamin D.
pcrh 12y ago
This is a model of how a Neanderthal man would look today: http://i.imgur.com/96DCsQt.jpg http://i.imgur.com/96DCsQt.jpg From the German Neanderthal Museum: http://www.neanderthal.de/en/ http://www.neanderthal.de/en/
- JoeAltmaier 12y ago
  That's very optimistic. Its not certain he could have buttoned that coat.
  - pcrh 12y ago
    Pfft! Also, no tie, how primitive!
    - brightsize 12y ago
      Well, assuming he's German, he's probably wearing blue jeans too. If this is a Berliner Neanderthal then he must have taken off the trilby and set down his MacBook for the shot.
- carsongross 12y ago
  Here's a more realistic version: http://www.independent.co.uk/incoming/article8528971.ece/alternates/w620/Andrea-Pirlo.jpg http://www.independent.co.uk/incoming/article8528971.ece/alt...
  - pcrh 12y ago
    Apparently Italians have more Neanderthal DNA than most... http://www.plosone.org/article/info:doi/10.1371/journal.pone.0059781 http://www.plosone.org/article/info:doi/10.1371/journal.pone...
DanBC 12y ago
Here's a grauniad article with a few more details of the research that is driving the changing attitudes. http://www.theguardian.com/science/2014/mar/23/neanderthals-and-me-go-back-a-long-way-alice-roberts http://www.theguardian.com/science/2014/mar/23/neanderthals-...
- bobgrumman 12y ago
  I'm really confused now. I read the article but don't follow it. I've read that we and chimps share over 90% of our genes. Therefore oughtn't we and Neanderthals share more genes than that? Certainly more than 2.4%. My guess is maybe it's 2.4% of the genes that human beings have and chimpanzees do not? Can anybody help me out on this?
bobgrumman 12y ago
I came into this with very little background, so forgive an ignorant question about something that must be very complex, but what does "Europeans consist of up to 5% or more Neanderthal genetic stock?" 5% of Europeans are Neanderthals?

25 points by pmcpinto 12y ago

Given that europeans consist of up to 5% or more Neanderthal genetic stock, it's increasingly untenable to look at the Neanderthal as some sort of "other". They is us.

kolev 12y ago
I'm European and I have about 2.4% (I know this thanks to 23andMe).
pcrh 12y ago
5% isn't all that small either, it's 1/20. On a population basis it would be the equivalent of 1/20 people being pure Neanderthal.
- mcv 12y ago
  No, that's really not the same thing. The Neanderthal genes have been quite dilluted over the millennia. Everybody has a tiny bit, and nobody has a lot.
  - pcrh 12y ago
    It depends on what you are considering. If 1/20 people of a population were 100% Neanderthal, and the rest 0% Neanderthal, over millenia, and assuming random mixing, the whole population would tend towards what it is today. So we are potentially heirs of a population where Neanderthals mixed with non-Neanderthals in a (very) broadly similar ratio as Europeans versus non-Europeans in the US today. I only intend this to illustrate that 5% is not as trivial a number as people often imply, and that it potentially derives from a population of Neanderthals and non-Neanderthals mixing in quite a "modern" fashion. I would add to this that one interesting fact concerning human-neanderthal genetics is the absence of Neanderthal mitochondria in modern humans. This may mean that Neanderthal women couldn't bear human-Neanderthal offspring, and if they could have, the proportion of Neanderthal DNA in modern humans might have been twice as high as it currently is.
duaneb 12y ago
Well then why bother discussing pre-homo sapien speciation at all? EDIT: To put it another way, you wouldn't compare a modern european to a neanderthal and call them part of the same people. The neanderthals still had large differences with other populations.
- carsongross 12y ago
  I'm not saying it isn't worth discussing pre-homo sapien speciation at all, I'm saying that the vague idea that the Neanderthals are some "other thing" from our genetic heritage (as compared with, say, Cro-Magnon) has become less tenable as genetic analysis has advanced. The story of Neanderthal is, for many of us, partly the story of us. Genetically, some of us have the equivalent of a great-great grandparent that was Neanderthal.

squozzer 12y ago

I believe in evolution but one question has always bothered me - when a social animal is born with a mutation (even one that is unquestionably superior), wouldn't the other members of e group kill or shun her? This question may sound far-fetched unless you're non-white or a ginger.

todd8 12y ago
No Most mutations wouldn't be obvious. They might affect metabolism or some enzymatic pathway. (Isn't it curious that Junior likes cow's milk?) These seem unlikely to be discriminated against. Even mutations affecting visible features might be gradual and require the accumulation of many mutations over generations and generations to become pronounced. (Height, skull size, dentition) Some features might be due to a single mutation and could be pronounced and obvious in new members of a group. Red hair might be one of these mutations, and perhaps some red headed children were spurned or killed or discriminated against by their group. But this wouldn't easily eliminate red hair. It is caused by a recessive gene so carriers of a single gene won't be redheads themselves. If two non-redheaded carriers of the gene have 4 children on average three will carry the red hair gene but only one will have red hair because they carry two of the genes. I find red hair attractive, and apparently so did our ancestors: red hair was not eliminated from the gene pool. Curiously, humans have evolved to retain juvenile features. This neoteny, as it is called, has resulted in smaller jaws, flatter faces, hairless bodies, larger eyes, and other features. Selection for these traits may be due to our instinctive desire to care for infants. Likewise mutations in the other direction, smaller head to body ratio, etc., could very well have suffered from negative selection pressures as you have raised in your question. I think these speculations are interesting and the answers are not obvious. Why, for example, has a trait such as mental illness, clearly having a negative impact on survival, not been eliminated? Is it just so tricky to get a brain assembled into a mind that there are inevitable difficulties? Or is it caused by interactions with viruses during development that are evolving in competition with us? What about nearsightedness? I wouldn't have been a very good hunter of distant game. Why hasn't myopia been eliminated as a trait? Is it because as I age I can still read without reading glasses? Were there elderly nearsighted arrowhead makers, able to do close work despite age related presbyopia, trading their skillfully made arrowheads for food? One additional observation. Your question mentions non-whiteness, suggesting that more pigmented skin is a mutation. It appears that it is just the reverse. Human evolution started in Africa where pigmentation would have been important because of the more intense sunlight. Lack of pigmentation would be a disadvantageous mutation. So the more accurate question is why would anyone even have light skin? The answer I've heard is that for humans groups that had migrated out of Africa to latitudes that had weaker sunshine, lighter skin allowed for better absorption of the weaker sunlight for the production of vitamin D.

pcrh 12y ago

This is a model of how a Neanderthal man would look today: http://i.imgur.com/96DCsQt.jpg http://i.imgur.com/96DCsQt.jpg From the German Neanderthal Museum: http://www.neanderthal.de/en/ http://www.neanderthal.de/en/

JoeAltmaier 12y ago
That's very optimistic. Its not certain he could have buttoned that coat.
- pcrh 12y ago
  Pfft! Also, no tie, how primitive!
  - brightsize 12y ago
    Well, assuming he's German, he's probably wearing blue jeans too. If this is a Berliner Neanderthal then he must have taken off the trilby and set down his MacBook for the shot.
carsongross 12y ago
Here's a more realistic version: http://www.independent.co.uk/incoming/article8528971.ece/alternates/w620/Andrea-Pirlo.jpg http://www.independent.co.uk/incoming/article8528971.ece/alt...
- pcrh 12y ago
  Apparently Italians have more Neanderthal DNA than most... http://www.plosone.org/article/info:doi/10.1371/journal.pone.0059781 http://www.plosone.org/article/info:doi/10.1371/journal.pone...

DanBC 12y ago

Here's a grauniad article with a few more details of the research that is driving the changing attitudes. http://www.theguardian.com/science/2014/mar/23/neanderthals-and-me-go-back-a-long-way-alice-roberts http://www.theguardian.com/science/2014/mar/23/neanderthals-...

bobgrumman 12y ago
I'm really confused now. I read the article but don't follow it. I've read that we and chimps share over 90% of our genes. Therefore oughtn't we and Neanderthals share more genes than that? Certainly more than 2.4%. My guess is maybe it's 2.4% of the genes that human beings have and chimpanzees do not? Can anybody help me out on this?

bobgrumman 12y ago

I came into this with very little background, so forgive an ignorant question about something that must be very complex, but what does "Europeans consist of up to 5% or more Neanderthal genetic stock?" 5% of Europeans are Neanderthals?