I've been interested in paleoanthropology as a layman for a few years now. I find the Mousterian [1] culture / tools quite interesting, because it appears to be part of the history of hominid technological progress, the stepping stone to Châtelperronian tools, and yet also seems almost wholly attributed to Neanderthals.
Perhaps I'm misunderstanding, but to me this suggests Neanderthals were actually more technologically advanced than humans at this time, and that as anatomically modern humans finally began to replace Neanderthal "civilization" they also adopted and used Neanderthal technology as their foundation.
Neanderthals were actually more technologically advanced than humans
I understand why this choice of words, but I think it is important to remember that Neanderthals were humans too. And, as we now know, not just "technically" human, but in many ways.
I don't know if this is appropriate, but why are extinct humans classified as different species while the still alive humans are all considered the same species?
It seems political. Either some of the current races are different species, or the so called extinct human species are just different races.
"Extinct humans" are not humans. They're homo, not homo sapiens (or, more strictly, homo sapiens sapiens).
The genetic differences between you and any other human being of any other race are vanishingly small both in proportion to the size of the human genome and to the (known) differences between sapiens and neanderthalensis.
I think that this is the usual definition of "human", but I also think that it doesn't agree with the layman definition of "human". https://en.wikipedia.org/wiki/Human
For a layman, an "human" is a "modern human", i.e. "Homo sapiens sapiens", i.e. me.
There are two difficult problems here. The first is how to classify animals species (including humans, whatever it means). The taxonomy classification is somewhat arbitrary. It's very useful for discussions between biologist, but arbitrary.
Currently Homo, Pan, Gorilla or Pongo are different "genus" of the Hominidae "family". (I hope I got all the notation correctly.) The genus is somewhat special, because it's written in the name of the specie, but we could have agree to write the family in the name two. We could have been "H. H. sapiens sapiens" and chimps could be "H. P. troglodytes"
The second problem is that we all agree that the sentence for killing a "human" should be different of the sentence for killing a cow or a pig. But the decision of what "human" means in that sentence is a political one, not a scientific one. Should we consider killing any great apes as bad as killing me? What about other apes? Why? Why must we use the taxonomy classification? What about whales and dolphins? Octopus?
True they are genetically different but that's not the definition of a 'species'. There is a level of politics in biology over what constitutes a species and what does not.
Technically a 'species' is something that interbreeds but does not breed with members outside of it's species and mating produces reproductive offspring. (at least this is the old mayr definition that everyone uses)
The problem is that neanderthals and humans matings produced viable offspring. So is 'neanderthal' a species or not?
The same issue is a problem with the Galapagos finches, which are the holy cows of darwinian genetics. By Mayr's definition they should not be able to interbred and produce viable offspring. However, apparently they can interbreed and therefore are not technically different species.
No one in science want's to badmouth the masters, so Darwin's theory of Galapagos finch species will quietly be put back in the Victorian cabinet while we invent a new 'genetics' based theory of 'species' that makes everyone happy. However, life is not easily classified. Viruses? Species? Bacterial plasmid replication?
There is a lot of politics in the life sciences. Naming a new species or having your name on a species is a big deal. It reminds me of Cope/Marsh and the dinosaur finds (https://en.wikipedia.org/wiki/Bone_Wars) of the early 20th century. They both screwed up the identification of many species so that they could out publish the other and left the mess for future scientists to clean up.
My feelings on this is that we still don't have enough evidence about the genetic makeup of humans to really make any conclusions on anything. Example:
What is the blood type in the reference sequence for the human genome?? We know that there is A, B, A/B and O which represent 4 different genotypes (an AA sequence, a BB sequence, an AB sequence and a missing sequence from both alleles).
If I sequence a neatherthal with blood type A and a human with blood type O, are we genetically divergent?? How can you come to this conclusion unless you know the plasticity of each genome. (i.e. I can't identify a nucleotide change in blood type gene for a type O human because the gene is absent)
It looks like most of the research has been on mtDNA which is passed from mother to child. If we can't find a mtDNA match, it might just mean that there is no maternal linage that can be traced back to that sequenced individual. (i.e. all the children of that mother died out at some point)
Different species? That's a question for politics imho. I personally think that life shuns classification. BTW sorry for the ramble :0
Then you have ring species[1] that blow a nice big hole in the interbreeding based definitions of species.
Species and race are vague terms we use for convenience. That's all. I think keeping them vaguely defined is a feature not a bug, because it could help prevent people assigning too much weight or meaning to them. If people get the idea that race and species can be precisely defined, then maybe they can be measured? Maybe we can use that to derive tests or policies? But trying to precisely define race and species is futile, like trying to put light in a box. I'd rather knowingly and consciously keep the ambiguity, to remind myself that the terminology isn't the reality.
One definition of a "market" is people with the same needs who reference each other (i.e. talk to each other). This transmission of information ("word of mouth") is important for marketung [...though perhaps a bit different today, with referencing internet reviews.]
Similarly, the definition of species as individuals that breed with each other has importance for transmission of genes. By this rationale, transitive gene transmission makes ring species a "species".
A biologist told me that species are defined, not by theoretical interbreeding, but by actual breeding...so that a single species divided somehow in different environments, is now two species, even when no genetic change has occurred.
By this strange extrinsic definition, the human races were different species before global travel... and now are one.
And that SV hackers who only breed with other SV hackers, are a different species (and the rise in autistism incidence evidences a genetic effect - in a few million years, interbreeding will be impossible!). Similar for classes, the 1% etc.Though there is crossbreeding in practice, so at most these are ring species.
No, it's just logic. Inclusion of populations in species depends on breeding ability. And there's no way to test that for fossil individuals vs each other or vs modern humans. So they can't be classified as the same species, or part of a species ring.
Because we have extensive samples of the Neanderthal genome extracted from bone fragments, and before that from morphological studies of the Neanderthal skeleton which display far greater differences from humans than any differences in skeletons between human races. Even 18th Century observers were able to see that.
Yes there is no one universally agreed definition of species, but Neanderthals were vastly more different from living humans than and differences between living human populations.
BTW is there a good comparison for how big the anatomical differences are between Neanderthals and modern Europeans, compared to the differences between modern Europeans and modern, significantly distinct populations such as Congo pygmies?
(Anatomic differences are perhaps not as important as cognitive and psychological differences, but the latter are very hard to find out about extinct populations.)
"A species is often defined as the largest group of organisms in which two individuals can produce fertile offspring, typically by sexual reproduction."[1]
As far as I know there is no evidence that neanderthal females could produce fertile offspring with a male homo sapiens -- but only the other way round.
Here's a study that finds that the inverse was actually impossible/exceedingly unlikely (homo sapien females carrying neanderthal male babies). This outside of my field, but wouldn't that mean then that it would have to be neanderthal females carrying male homo sapien's babies in order for the genomic remnants to be observable?
The study seems to suggest only babies that were themeselves male would have trouble making it to birth. So female babies being born to homo sapiens mothers would still be half-neaderthal, they just wouldn't have Y chromosomes which is what the study was tracing ancestry through.
Race is a social construct, there's no biological explanation for race. The set of characteristics that are identified with different races are social constructs, those clusters of features does not correlate to a significant difference in biological terms. Genetic methods do not support or explain the classification of humans into discrete races. Races are not genetically homogenous and lack clear-cut genetic boundaries.
Two people from different races can be way more similar genetically than two people from the same race. The concept of race was built over a long story of separating humanity in different ethnic groups, and then physical characteristics of some of those ethnic groups started slowing being adopted as a mean to show that those people are intrinsically different, but they are just an unimportant set of characteristics that does not convey important information from a genetic perspective, they gained social meaning through culture. The modern concept of race took form in the enlightenment, https://twitter.com/Limerick1914/status/757227361582608384, when the original western notion of which ethnic groups exists in the world was built into a racist anthropology.
That doesn't mean that "all lives matter" or we shouldn't talk about race. Race is a social construct, and as a social construct, it exists. Money is also a social construct. But, the concept of race makes no sense besides the social structure that was built on. That why different countries consider that the set of existing races is different, for instance, the only country that really considers "latino" a race is the US.
Going back to your question, the extinct humans actually had important biological differences, the different races have not.
Honestly, I think calling something "a social construct" is meaningless political rhetoric.
If humans and Neanderthals interbreed for a long enough period without annhiliating each other through war, wouldn't their offspring converge over time?
Some ethnicities are more susceptible to certain diseases. Is that a social construct?
Our standard conceptions of race are also meaningless political rhetoric, so calling race a social construct seems entirely appropriate then.
We still, at least subconsciously, apply the "one drop rule" in all sorts of situations, including describing the race of the current US president. Sub-saharan Africa contains more genetic diversity than everyone else, yet we lump them all together in one "race."
Yes, there are distinct genetic differences between various groups of people, and many of those differences have real-world consequences. But the relation of those groups with what we call "race" is almost zero.
> But the relation of those groups with what we call "race" is almost zero.
The everyday races correspond to real, observable genetic clusters. There are real characteristics shared by members of these large groups, e.g. the epicanthic fold in East Asians.
The genetic phylogeny doesn't lie. The Sub-Saharan diversity you're mentioning --- e.g., between Bushmen and the Igbo --- is about large-separation clades within the larger continental grouping.
There are some real characteristics shared by some members of those large groups. Certainly not all of them, considering the arbitrary rules. 10% of American "blacks" have majority white ancestry. Are you telling me that they still have all of the real characteristics shared by others of the "black" group?
This stuff does not line up neatly. To the extent that there are genetic differences between groups of humans, the dividing lines don't match our concepts of race.
Some ethnicities are more susceptible to certain diseases. Is that a social construct?
Obviously not. But quoting Wikipedia[1], an average of 85% of genetic variation exists within local populations, ~7% is between local populations within the same continent, and ~8% of variation occurs between large groups living on different continents, whereas [a]pproximately 10% of the variance in skin color occurs within groups, and ~90% occurs between groups, which indicates that this attribute has been under strong selective pressure.
When defining human race, we hone in on a few easily identifiable characteristics that have remained stable due to selective pressure (eg skin colour) and overblow their significance. Eg we suspect that humanity went through a genetic bottleneck when it left Africa, decreasing diversity. And yet, we generally lump the rather diverse African population that did not go through it into a single race.
It's probably more useful to just look at specific genetic traits of interest instead of drawing somewhat arbitrary boundaries.
> 85% of genetic variation exists within local populations
That's Lewontin's Fallacy [1]. There's no logical reason to think that genome-wide diversity within populations somehow proves that large-scale impactful allele frequency differences between conventionally understood races do not exist.
They do. You can measure them. Given someone's DNA, you can identify his content-scale race. (You can actually narrow someone's ancestry much more narrowly too. Race is a cakewalk.)
"In popular articles that play down the genetical differences among human populations, it is often stated that about 85% of the total genetical variation is due to individual differences within populations and only 15% to differences between populations or ethnic groups. It has therefore been proposed that the division of Homo sapiens into these groups is not justified by the genetic data. This conclusion, due to R.C. Lewontin in 1972, is unwarranted because the argument ignores the fact that most of the information that distinguishes populations is hidden in the correlation structure of the data and not simply in the variation of the individual factors. The underlying logic, which was discussed in the early years of the last century, is here discussed using a simple genetical example."
There is also no logical reason to believe that allele frequency differences betwen conventionally understood races are in any way "impactful" relative to the heterogenity of respective groups or relative to allele frequency differences between populations not generally understood as distinct races.
We can reliably identify haplogroups associated with certain phenotypes popularly categorised as "races", but we can also [more] reliably identify genetic markers associated with other phenotypical differences which have little or no correspondence with haplogroups. The presumption of greater significance of haplogroup-associated differences is the social construct here.
I repeat, attributing more significance to observed similarities than observed differences is a social construct. One minute we're talking about fairly obvious visible differences like Korean-descended people almost invariably having paler skin and narrower eyes than Bantu-descended people. You also mentioned stature, which is rather less helpful to your thesis because there's a huge range of average heights between different Bantu subgroups and on average North Koreans are substantially shorter than their genetically difficult-to-distinguish southern cousins. Except for someone like Ri Myung-hun, who's over 7'8". Would one say his stature is best evaluated by analysis of the average height of people bearing "Korean" genetic markers or using a tape measure?
And of course, inevitably you move on to pretending that the huge and stable variation in measured test performance within a population is of lesser import than relatively small and unstable difference in average test performance between populations. Even if we grant the rather silly proposition that tests so unstable that the Dutch population improved by more than a standard deviation in thirty years are actually a good measure of innate intellectual differences unaffected by non-genetic factors, you've got the problem that it's impossible to predict with any degree of certainty what the person who took the test's genetic background actually is. I mean why would anyone interested in investigating innate intelligence choose to focus on genetic markers that predict my skin tone pretty accurately but can't even rule out the possibility of me being in the very top or very bottom percentile for results in any cognitive ability test?
> the Flynn effect changes the absolute scores, but not the difference.
I'm going to go out on a limb and suggest that if a test indicates that me and my fellow white English thirtysomethings produce average scores a standard deviation ahead of (i) thirtysomething black people living in my country and (ii) my white grandparents' generation when they were my age, what's actually measured by the observed one standard deviation average differences across cohorts probably isn't genetic differences....
It's not at all meaningless but reflective of the fact that notions of race (or something like it) are entirely subjective and variable across cultures, even across time within cultures. Whites, as an American example, did not in our recent past include all kinds of people from countries in the Mediterranean or Eastern Europe. The same is true of ethnic categorizations.
And yes, some ethnicities being susceptible to diseases is a social construct because ethnicities follow the same shifting standards. Your talking about the intersection of an imprecise categorization with biological understanding that is only dependent on the latter to remain true. It's useful today because (in some societies) it can signal aspects of biology. But human societies in the future could have entirely different notions of race and ethnicity that change or renders the overlap meaningless.
So? Skin colour and body shape are determined by environment as well as by genes, and race is determined by social factors as well as by skin colour and body shape. It's at least as convoluted a process to get from genes to race as it is to get from genes to wealth.
You're accusing me of politicizing facts, but seeing race in and around normal human variation is itself a political act, even if it is an innate prejudice.
It is dialectically true that "social construct" and "figment of the imagination" are two different things. It is rhetorically false; in rhetoric calling things "social constructs" is clearly an attempt to simply label them as figments of the imagination.
Huh. You really believe that people who say that race is a social construct are trying to label it as a figment of the imagination? That's not my intent, at least, and I doubt very much that it is the intent of anyone who makes that claim in good faith. I'm not trying to argue using rhetoric; I'm saying that if one tries to segment human variation into races ignoring societal attitudes, one will either fail entirely or will arrive at "races" that do not correspond neatly if at all to society's conception of race. That is the sense in which race is a social construct.
Race absolutely correlates with genetic clusters. Look at this map, [1], and say that there's no correlation between genetic markers and continental origin. Forensic anthropologists can identify race very well using nothing but bone structure.
The idea that race is scientifically invalid is complete nonsense. You can argue that race doesn't correlate with phenotypical characteristics that we care about (okay, but it does though), but arguing that race itself is just in our heads is nonsense.
Is it any wonder that more and more people distrust science on issues like evolution, climate change, autism, and so on when scientists claim that you can't really tell whether someone is white, black, or asian?
> The idea that race is scientifically invalid is complete nonsense. You can argue that race doesn't correlate with phenotypical characteristics that we care about (okay, but it does though), but arguing that race itself is just in our heads is nonsense.
You couldn't be more wrong.
My mother is Puerto Rican, and my father is mostly Irish (with some ancestors from other European countries). My 23AndMe results show that all of father's genes are from Europe, and my mom's come from Europe (mostly Spain, but with a tiny bit of Ashkenazi), Africa, and the Caribbean (Native Americans, likely the Tainos).
My genetic makeup is roughly 7% Native American, 14% African, and most of the rest is European; some percentage is inconclusive.
You may be able to guess that I mostly look white, and you'd be correct. However, with my mother being roughly half non-white and half white, what would you guess? I'll tell you right now that I wouldn't guess that she's from Europe, but she does have relatively light skin. Her sister, however, could easily pass for a black person.
To think that your phenotype can be determined just by looking at your genes is ridiculous, and it's clear to me that you have very little experience in diverse environments. Things like skin and hair color are complex and are determined by multiple alleles, and there's no way to know which ones are going to be dominant.
Even aside from genetics, the social construct of race is even more complex, and I challenge you to do more reading on why that's the case.
Edit: To add more fuel to this, most of my girlfriend's genes come from China and surrounding areas in the Southeast. If we have a child, what will they look like?
Roughly 3.5% Native American, 7% African, 39.5% European, and 50% East Asian. Tell me, what race will they be? What about their phenotype? There's simply no way of knowing. Scientifically, race just does not exist.
Why would it be surprising that the child of someone who is white and someone who is half white might go on to appear mostly white? You yourself mention that your genetic makeup (presumably from 23andme or something) also suggests a "mostly white" appearance. In this case, there's a pretty good match between phenotype and genotype.
You absolutely can predict someone's phenotype from her genotype, roughly speaking. In cases of recent admixture, the exact gene expression can be uncertain. Just look at Mendel and his peas! Even this variable heredity has limits. There was a zero percent chance that you'd end up looking like a typical Japanese person.
I don't understand your point. I'm not claiming that the classic races are fixed for all time. I'm not suggesting that we can't arrange genes in new combinations. I am claiming that people today cluster in certain historically-contingent ways and that these clusters reflect the everyday understanding of race.
It seems like you don't understand my point because you've ignored the fact that my mother and her sister look they belong to different races, despite having roughly the same genetic makeup (about half white and half non-white). My result is not surprising; theirs are, however.
As another commenter said, what about Obama? I've met people who are half black and half white and end up looking like white people. Obama doesn't look like someone from Africa, nor does he look like someone from Europe. Because of what society determines as being white, most people would say, "he looks more black," which isn't really true, but regardless, you likely would not be able to tell just by looking at his genetic makeup. Many people in the same circumstance look wildly different from him.
If your argument is that when someone's genes all come from one area, then you can take a guess at what they might look like, then sure. But to apply that blanket statement to the entire world is just not the case. There are parts of the world where those lines get very blurred (e.g. Turkey, Nepal, Afghanistan), and plenty of people who are of "mixed descent" with different phenotypes from you would predict from their genes.
I don't see it as very surprising that your mother and her sister look like they belong to different races. That's how genetics works in case of individuals; siblings can get different sets of dominant and recessive alleles from their parents.
In terms of population, things then average out. There are indeed parts of the world where things are very blurred because of extensive human interaction across populations. If every place in word were like that, then there indeed wouldn't be what we call races. But most of the world is not quite like that, and particularly, in the course of history it hasn't been.
Race and "continental origin" are only vaguely related.
For example: what race is the current President of the United States? Most would say "black" (or "African American" if they're trying to be politically correct). And yet his ancestry is half European.
This is hardly an isolated example. The average African American has about one quarter European ancestry. About 10% of African Americans have a majority European ancestry.
Yes, you can use genetics to divide up humans into related groups. But those groups will not match with how we divide up races.
Could you list what races you think exist, and some kind of paper that establishes a scientific method for where the dividing lines in the genetic gradients are drawn and why such a line needs to be drawn at all? That is, going from DNA to races, and not vice versa. Is there still an Irish race for example?
Also, is it worth pointing out that the people who don't believe in climate change, think vaccines cause autism, think evolution and fossils are a hoax etc. could make your exact claim about how scientists not coming clean on their pet subject and rather intentionally misrepresenting the facts to the public for whatever nefarious reason makes it their own fault that no-one believes in science.
How do you convince yourself you're not one of them and therefore actually the cause of the very problem you lambast scientists for? I'm sure they have books with nice diagrams proving them correct too.
> Could you list what races you think exist, and some kind of paper that establishes a scientific method for where the dividing lines in the genetic gradients are drawn and why such a line needs to be drawn at all?
Let's define our terms. By "race", I mean the classic continental groupings of people whose ancestors come from areas centered on Europe and the near east, east Asia, and Sub-Saharan Africa. When we say "race", we're talking about that category to which people readily self identify and to which we can easily assign others. When we say "race exists", it means that these categories are not arbitrary.
More generally, they're big ancestor clusters. You can see the clusters yourself if you take genome corpuses and run principal component analysis (or other grouping algorithms) on them. If you select k=3, the classic continental races come out of the data.
I'm not sure how much more real a taxonomic classification scheme can get. We use the same genomic approach for organizing the rest of life.
With more groupings, you get finer-grained population clusters nested inside the larger ones. If you look for enough clusters, you start seeing an "Irish" grouping. Can we agree that, say, the Irish, the Italians, and the Slavs are distinct hereditary groups? Can we agree that they're more similar to each other than, say, the Irish are to the Pygmies?
You could, in principle, put everyone into her own cluster. Sure, at k=7e9, race doesn't exist. But that's not a very useful classification scheme, because it ignores the reality that there are high-level classifications that we can see with our own eyes.
> How do you convince yourself you're not one of them and therefore actually the cause of the very problem you lambast scientists for?
That's an excellent question. Epistemology is hard. The best we can do is try to explain observations using the best-predicting theories we can find. I reject the "race does not exist" theory because it fails to explain observable facts about the world. This theory requires, in order to explain our observations, elaborate systems of oppression. It's full of epicycles. Even so, it fails to predict the result of studies like the Minnesota Transracial Adoption Study.
The "race corresponds to allele clusters" theory makes better predictions. It explains heritable and persistent differences in measurable characteristics. It agrees with genomic observations. It requires no hidden assumptions. This latter theory isn't politically correct, but this status can't affect its truth value. We delude ourselves about things all the time.
Look: the traditional continental race classification scheme is a crude folk theory. It's very embarrassing for science when even a crude folk theory makes better predictions than the best theory to come out of the academy.
So you seem to agree more with the "race is a social construct" people than it first appears since all the boundaries you talk about are fuzzy and arbitrary, you even suggest that people must be able to distinguish them with their own senses for them to be meaningful, and that if it's not a useful tool to humans then it's pointless. All of which sounds very social construct-ish to me.
Possibly you're just talking past each other, and don't fundamentally disagree at all.
When you take a big corpus of genomes and split them using impartial mathematics into similarity-clusters, you get clusters that almost perfectly match the continent-scale races that people self-report. That's not "arbitrary". Furthermore, people in these groups differ in characteristics that are measurable and important.
When I say that "race exists", I mean that there are real differences between the k={3,4,5} groupings and that almost always tell someone's group affinity by sight alone. The existence of marginal cases doesn't somehow invalidate the reality and utility of the high-level groups.
When people say "race doesn't exist", the general public reads that as "there are no differences on average between people from the various continents", and this claim is not only false, but it's so false that one doesn't need sophisticated instruments to tell.
I believe that this confusion is deliberate and is part of a misguided attempt to eliminate bigotry by delegitimizing the classification schemes upon which bigotry is built. This strategy is doomed, because you can't take away people's eyes and ears.
I think it's an honest question, even though it's controversial and attracts downvotes. (I noticed your question is in gray right now.) In my mind, it's a question of a "big enough difference" in a day-to-day-like mode of thinking. Since I'm not a biologist I'm only using my own version of how I think of it.
I personally think of the concept of species, etc., as "shades of gray" that change depending on the lighting. (If that makes sense.)
Look at the huge differences in dog breeds, for example. If I didn't know better I would think some dogs are a completely different class of animal when compared. (Think chiwawas and german shepherds, in their visual appearance.)
Sometimes I think of my dog as a person. Other times, not so much. Is it political? I think some people could make some sort of (weak) argument for that; in how I allocate resources to my dog, and why I do it. Why I even keep a dog around.
Also depends on how you'd define politics; how broadly and deeply. In this case I think your question it's a very interesting one, if we were to imagine running into a fresh population of neanderthals I bet there would be political ramifications between groups!
As a layman my go-to definition of a species used to be the one given by Bamberg below (and for all practical purposes it still makes sense). Modern human races can interbreed and have fertile offspring. Therefore they don't constitute different species.
One thing that many don't realise is Neanderthals aren't gone, because many of us are part Neanderthal. The distinction between what is Neanderthal and what isn't has just been blurred. It would be kind of like saying your mother's lineage went extinct because she had a child with your father.
If 1-4% of the Eurasian genome comes from Neanderthals, but sub-Saharan Africans have no Neanderthal genes, does that mean that the EA genome differs from the SSA one by 1-4%? And even more so the Melanesian genome, which has 4-6% Denisovan DNA. But at the same time, chimpanzees and humans supposedly share over 99% of their genome. How is that possible? Are these all percentages of the same whole, or is there something else going on?
That's measuring different things. We can tell whether a particular copy of a gene came from the Neanderthal gene pool or the main SSA gene pool by looking at its sequence (esp. at SNPs), but the overall base pair sequence of that gene will still be 99.9% the same.
When we say that chimpanzees and humans share 99% of their genome, we're looking at base pairs, but when we say that modern Eurasians have 1-4% of their genome from Neanderthals we're looking at genes.
Because we were already 99.x percent the same as Neanderthal, so if you take 4% of a Neanderthal genome and replace those sections in a human genome, not very much actually changes.
Of normal human genetic variation, 1-4% is sourced from Neanderthal DNA, which sub-Saharan African peoples do not share. They still may share up to 96-99% DNA variations. In absolute terms they share in excess of 99.9%[1]. The variations inside ethnic groups are almost 16 times larger than the variations between ethnic groups.
What I found interesting is that, while any given modern human has no more than about 4% Neanderthal DNA, it isn't the same 4% in everyone. About 20% of the Neanderthal genome is found in humans. I'm not sure what this says about interbreeding.
And then there's the Denisovans... I gotta get my DNA done...
(A) Proportion of the genome inferred to be Denisovan in ancestry in diverse non-Africans. The color scale is not linear to allow saturation of the high Denisova proportions in Oceania (bright red) and better visualization of the peak of Denisova proportion in South Asia.
(B) Proportion of the genome confidently inferred to be Denisovan in ancestry in mainland Eurasians plotted against the rate of allele sharing of each sample with non-West Eurasians as measured by an f4 statistic. Error bars (1 SE) were obtained from a block jackknife. The Denisovan ancestry estimates in South Asians are systematically above expectation (fitted trend line) (p = 0.0013).
I've seen work suggesting that some of the surviving Neaderthal characteristics are pale skin, freckles, straight hair, brown, blonde and ginger hair. That might not be a high proportion of the genome but it sure is noticeable.
When anatomically modern humans migrated from Africa to Europe, their immune systems were not as adapted as neanderthals. So the humans that crossbred had increased chances of surviving, were healthier and more fertile.
Then, most genes not related to the immune system were removed through natural selection creating the modern mix.
I think you have a few errors in your explanations.
There is not enough evidence about the immune system of the neanderthals. When the Out-of-Africa migration(s) happened, there is no evidence that the neanderthals had encountered significant diseases and epidemics in the past -- up to that point. This does not rule out the possibility that they neanderthals were spreading some unique parasites amongst themselves. Disease is all about congestion [1].
What the neanderthals had that was most beneficial to humans was geographic adaptation. And the are genes for that can jump-start (by many generations) the evolution of features like longer and more straight hair.
Also, during Natural Selection genes that become useless will stay in the gene pool. Natural Selection selects for advantageous genes [2], that does not mean that it selects against neutral (useless) genes. DNA has no size cap and the gene pool of organisms continues to hold onto the genes long after they offered a survival edge [3].
[1] It is also congestion that increases the likelyhood that a disease jumps species.
[2] And by compliment, against disadvantageous genes
[3] This is a virtue of DNA, it likes to keep a memory bank of all solutions that have been useful in the past. It is a hoarder.
Just to elaborate, because eukaryotic genomes are so huge the marginal cost of copying excess genes is negligible so the selective pressure against them is as well. But prokaryotes have very small genomes and reproducing useless genes would be relatively disadvantageous for them so there is noticeable selective pressure to eliminate useless genes for them. So you will see the frequency of unused genes in bacteria tend to decrease over time.
> Also, during Natural Selection genes that become useless will stay in the gene pool.
That is absolutely true, but useless genes have a much higher probability of getting corrupt by accumulating errors, because the lack of useless genes is not selected against.
> I’ll start with a confession, an embarrassing but relevant one, because I would come to see our history with Neanderthals as continually distorted by an unfortunate human tendency to believe in ideas that are, in reality, incorrect — and then to leverage that conviction into a feeling of superiority over other people. And in retrospect, I realize I demonstrated that same tendency myself at the beginning of this project.
It seems he didn't learn much from the experience. Gibaltrar conflicts with Spain are not exclusively about the territorial aspect but rather it being a prominent haven for human and drug trafficking. Their locals are a constant embarrassment source for the U.K. government and for the most part treated like corsairs, tolerated in public but rather frown upon in private. Possible the worst of both Spanish and British 'maritime' traditions.
The coastal towns in the area are splendid though, and worth visiting indeed.
> Gibraltar is adjacent to known drug trafficking and human smuggling routes, but the territory is heavily policed on land and at sea due to the risk of these activities occurring within its borders or territorial waters
Sir, if you were superior you would not have written "more superior than"! A neanderthal would simply have written "superior to". I tell ya, these homo sapiens they come over here they take our jobs, talk all foreign and mangle our grammar. When I were a lad all this were pygmy and dinosaurs.
I find it interesting that the "solution" to the scientific question if all living humans are the same species is to claim that all the ancestors of living people belong to the same species despite all the genetic evidence saying otherwise.
Rather than deny reality, the alternative would be to say that current populations are not the same species, but that the differences are unimportant. Why does it matter if we are not all the same species if the differences are minor?
Why define interbreeding populations which have an order of magnitude more genetic variation within them than between them as separate species? Now that sounds like a definition which would owe more to racial politics than science.
Indeed the author's point was more or less the opposite: that Neanderthals were still "people" in the sense they tended to exhibit quite similiar behaviour and capabilities to homo sapiens sapiens despite their DNA actually being quite substantially different to the point you could meaningfully define them as separate species.
>Why does it matter if we are not all the same species if the differences are minor?
Because like it or not, we still live in highly volatile, dangerous political times, and scientists getting behind the idea that there are clear racial lines dividing us all will not contribute to the peace-making. Its an uncomfortable truth that sometimes science is really hindered by politics, and this is one of those situations where its a highly, highly charged subject with potential to create a significant degree of upset in the world. The human species is very rarely actually prepared for the truths of science.
So your solution is to pretend science hasn't found what it has found because of the fear it might be misused?
Rather than corrupting science, isn't it better to say we have no evidence of any important genetic difference between the different populations of the world? There are better ways of avoiding the evils of racism without destroying science.
Science isn't being corrupted - people can still write the papers they want, and the eugenics thing is all about that, as well as CRISPR, et al., - but would you be content with a tin-pot dictator in Europe using these kinds of "scientific facts" as a means of developing policies which encourage ethnic cleansing? Because, well, that's sort of still happening as a thing, and won't go away as a thing, until we find a scientific solution to hatred and intolerance. Which are still very much huge things.
> scientists getting behind the idea that there are clear racial lines dividing us all will not contribute to the peace-making.
I disagree. Science promulgating obvious falsehoods like "race does not exist" breeds distrust of all science. Science needs to acknowledge that race exists in order to save science from the postmodern nihilism of politics. The world is never made a better place through scientific censorship.
"Scientists found additional similarities between the frog genes and human genes. For instance, genes in frogs have very similar neighboring genes as humans about 90 percent of the time. In other words, the frog genome contains the same sort of “gene neighborhoods” as the human genome. "
Yes all living organisms have genetic similarities because we are all decended from a common ancestor, but I am unsure how comparing a frog to a human is relevant to the question at hand.
Science got it wrong because there isn't much science to it at all. It's like bone reading and the article manages to say that in a much more eloquent way.
If neanderthals were alive today, respectable people would call them homo sapiens sapiens and it'd be racism to suggest otherwise. Any evidence that you could distinguish neanderthals on the basis of genetics or morphology would be called pseudoscience and people like Stephen Jay Gould would publish elaborate sophistries explaining why anyone who notices differences between neanderthals and humans is a wicked person.
> We’ve always classified Neanderthals, technically, as human — part of the genus Homo.
I feel uncomfortable letting scientists decide whether an organism is 'human' or not.
Shouldn't that designation be the province of a great human, a Nobel Peace Prize winner, someone like Mikail Gorbachev, Henry Kissinger or Yasser Arafat?
Because success in one field, such as politics, is no indicator whatsoever of aptitude in an completely unrelated field, such as genetics or anthropology.
Perhaps I'm misunderstanding, but to me this suggests Neanderthals were actually more technologically advanced than humans at this time, and that as anatomically modern humans finally began to replace Neanderthal "civilization" they also adopted and used Neanderthal technology as their foundation.
[1] https://en.wikipedia.org/wiki/Mousterian