multi regional or replacement (out of africa 2) hypothesis which one do you believe and why

a reply to: peter vlar

"We" might not have made it very far were it not for the assistance of the Neanderthal we encountered in the Levant who actually had better lithic tool kits than the HSS who were on their way out to explore the rest of the globe. It's one of the first areas where we made friends and relationships with a foreign hominid species, lived with, worked with, loved with and shared with one another. The fact that we see grave sights with both species buried amongst each other with similar grave goods testifies to the familial and relationship bonds created between both species, at least in my opinion and I feel this is supported additionally by the genetic data.

and from the article that Luthier posted:

Moreover, by embracing the replacement hypothesis and Mitochondrial Eve, anthropology went along with the trend of reducing all biological evolution to genetics. Anthropology had fossil evidence and forms of analysis different from the dazzle of genetic computation. What genetic computation cannot deliver is the full range of the evolutionary process, where evolutionary change can occur with or without genetic modification.

I read the article posted by Luthier again this morning. I find the arguments somewhat confusing. If the common ancestors of Denisovans and Neanderthals are the same species as the hominids "Out of Africa", why does their genetic profile have distinct variations? It's my understanding that the Denisovans and Neanderthals died out. To me that means that either another species killed them off or they died out as a consequence of some environmental impact. Interbreeding, which most likely occurred, doesn't account for the notion that they "died out". Is there fossil evidence of "half breeds"? If the Neanderthal and hominid DNA was successfully integrated, I would expect to find fossil evidence of an "in between" Neanderthal/hominid with a fairly balanced ratio of genetic characteristics. Are we considered that "in-between" hominid because we carry some of their genes? On a side note, I have the highest level of Neanderthal genes - 3% - according to 23andMe.com. Has the percentage of Neanderthal DNA diminished over time such that we don't see the original distribution?

Another concept I find confusing is mtEve. It seems more logical to me that there must have been more than one mtEve because she had to descend from a group of hominids who already had mt genes which may have had an admixtures in their DNA. Why isn't it more likely that hominids formed different groups which then evolved independently of each other? So when the Cambrian Explosion occurred, these groups either died out or evolved very rapidly into a variety of species. If one of those groups turned out to be the Neaderthals or the Denisovans, doesn't that make them a different species who evolved separate and apart from "our" group?

(I'm not an anthropologist so I'm just following the logic as I see it)

Thanks for your contribution.

a reply to: luthier

I don't understand how anyone could believe that the Out of Africa theory has a serious contender. If you look at the genomics (and yes I have, I have a degree in Bioinformatics) it is abundantly clear that the level of diversity of Mitochondrial DNA and Y Chromosome Variation seen in Africa is the greatest (and contains the oldest variations). That is one reason to suppose Out of Africa is the most likely cause.

Now this gets complicated, when early Homo sapiens decided that Homo neanderthalensis and Denisova hominin (Homo sp. Altai or Homo sapiens ssp. Denisova) were someone they wished to breed with. It remains apparent that the sapiens came into the ranges of the other two hominins.

I say this, as I said, as someone who has played with the data.

a reply to: Phantom423

The concepts of mtEve and Y-Adam are not really helpful in a lot of ways, not unless you think about them with the Bible taken away from the equation.

Given we get our mitochondria (mt)ONLY from mommy, then yes there was at some point a single source of that mt (14oK years ago). BUT she was most likely not the ONLY woman around, we just only have mitochondrial decendants (and mutants there of) from her. The others died out. Sadly Creationists think she was the first woman ...

Similarly Y-Adam (who was around sometime 50 K to 80K ago and never met mtEVE) was not the only guy around (unless we suddenly went from a single sex species to a dual sex one (not serious)), just his lineage (and mutants of it) managed to have surviving decendants.

What this does is two things.

(a) Eve happened before Adam (well before) and the Bible best fix that
and
(b) Had Geneticists give the "clans" (clades) silly bloody names. So no you might not be a descendant of Genghis Khan, they just called it that (we have not sampled his remains ... as we don't know where they are)

I know you probably knew all that, just putting that out there

Edit

Missed the Neanderthal bit

Only some of the traits we got from the Neanderthals were helpful (we got some unhelpful stuff too), and its implied interbreeding was minimal (we don't know, but likely) so yes it gets diluted down, to what we see now. We see certain regions with upto 5% Denisovian (many Melanesians ... no where near Siberia where we first see the Denisovian clues)

originally posted by: Noinden
a reply to: luthier

I don't understand how anyone could believe that the Out of Africa theory has a serious contender. If you look at the genomics (and yes I have, I have a degree in Bioinformatics) it is abundantly clear that the level of diversity of Mitochondrial DNA and Y Chromosome Variation seen in Africa is the greatest (and contains the oldest variations). That is one reason to suppose Out of Africa is the most likely cause.

Now this gets complicated, when early Homo sapiens decided that Homo neanderthalensis and Denisova hominin (Homo sp. Altai or Homo sapiens ssp. Denisova) were someone they wished to breed with. It remains apparent that the sapiens came into the ranges of the other two hominins.

I say this, as I said, as someone who has played with the data.

I say this because we don't have a clear understanding of genomic decay.

Also as we find homosapiens from 300k years ago. and a possible human ancestor in Germany from 9.7 million years ago (possibly) show we don't have even close to a clear understanding of the entire evolutionary process.


Are you certain you understand how DNA changed over 9.7 million years.

If mtdna eve is 140k years old how are there 300k year old fossils?

pushed the emergence of modern humans back to at least 300 kya and possibly even to 350 kya. Funny how not so long ago we used to think our species emerged 100 kya, then 200 kya, and now 300-350 kya isn’t it?

rperon1017blog.wordpress.com...

www.uu.se...

Prehistoric Fossils Dating Back 9.7m Years Could Rewrite History Of Where Humans Came From

www.newscientist.com...

www.newscientist.com...


Just to be clear I don't believe in anything in particular. I think OOA has the most research behind it. But I have seen many ideas change in science in my lifetime as new data is presented or old data is reinterpreted.

a reply to: luthier

MtDNA Eve has had a couple of studies done so in. WY, you're correct in that the mutation rate might not be as pinned down as some would like to say. One study places her at 99-130 Ka and another at 170-240 Ka so the General average is considered 100-240 Ka. Now the reason we can say that our DNA Can be pushed back to ~300Ka is because MtDNA Eve isn't the oldest female HS but because she is the MRCA, The Matrilineal Most Common Recent Ancestor of all currently living humans. There were many other females at Her time and earlier but with all of the bottleneck events from Toba to the Black Death, all other lineages died out. Toba T 70 Ka nearly wiped out almost all surviving members of our genus to as few as several thousand breeding pair. The Black Death killed off 1/3 of Europeans and sterilized half of the survivors Those 2 events alone wiped out a lArge degree of genetic diversity and they are just 2 two well known events.

MtDNA Evenisnt the original HS female, just the most recent one whose genes survive until today.

a reply to: peter vlar

I kind of understand that as a lay person with a little cultural anthropology (mostly in ethnomusicology) but I am.not sure I get what that means in terms of the actual evolutionary process.

I personally believe we are far to early in the understanding of ancient DNA to get a sense from the DNA alone about the process of man's evolutionary travel from hominids.

I completely understand multiregional type of thinking can be tied to racist thought but in my case I am just wondering if it's possible the travel through the globe and in particular tell knowledge gained from survival in different climates wasn't a larger factor in the ecolutuonary process than trying to describe migration through Africa.

Or that smaller fragments of old dna from other paths weren't bread out over 100's of thousands of years seeming to not exist at all. I mean if the ancestors died out and never bread again or cross bread.

I think the footprints are interesting, though I am sure some other explanations are possible.

300kya is an awful long time with limited data to complete a puzzle. 3 or 5 million is very difficult. I know the geological record is there to study but the biological is more difficult. Finding pathology in the early eras would be very difficult

a reply to: luthier

Ok that possible "human" ancestor from Germany. Based on some teeth, and not more bones? Ignore that. No one said that there were not apes, or other primates else where. We can't get DNA from those teeth (too old) thus we do not know where they are in the "tree of life".

The y places which try to use genomic decay as an argument for something tend to be creationist sites. Expand that point please so I can talk to it.

I don't think you understand the point about mt-Eve. I tried to make it clear. She was not the ONLY woman. There were clearly females before her. Her lineage is the one which survived. Given the Toba event was one genetic bottle neck, there may have been others, and only her descendants survived?

So that was a non sequitur. Probably unintentionally. a Single female source from whence all the mitochondrial clades came from? Why is this an issue?

a reply to: Noinden

I understand your point fine.

I just don't know that the evolutionary process of man can be shown from DNA alone.



Or that the teeth were not hominid

Or that the footprints in Greece can be explained away.

I have a philosophy degree with a focus on cosmology. I am in no way a creationist though I am open to the possibility of a designer and knowing we can in fact design and edit genes is certainly proof it's possible.

My approach is from philosophy so you have to forgive me there, however itis also frustrating to hear scientists who are so focused on the micro data they can't see the forest. In cosmology we have to work together since the data is confusing philosophers are actually part of the scientific process. Less so in biology. Which is what also makes people like Dawkins dreadful philosophers but good specialists.

The decay of genes I refer to is the importance of the ancestors of modern humans in the genetic path that were fractioned out of existence over 100's of thousands of years. As well as the literal decay in the ancient fossils.

So what if the other humans frim other lineage were killed off by disease and did not continue to mate with the line from mtdna eve? What if the mtdna eve were the line of survivors that kept breeding and pushed out the other DNA over 100's of thousands of years of breeding with only mtdna eve line?

a reply to: Noinden

Thanks for the information. I still don't understand why different groups of hominids which spread around the globe could not be considered a different species. Primates and humans have about 95% DNA in common and they're referred to as a different species. I find it hard to believe that we're all just one big melting pot that walked out of Africa.

As for mtDNA, all primates have mtDNA which, from what I read, mutates faster than human mtDNA. If primates are a common ancestor of humans, then why do we need a "first" woman? What's the significance? Whoever this woman was, she didn't appear out of the blue.

I didn't get an answer from Peter - would like to get his take on my question as well.

Thanks again for the info.

a reply to: luthier

Ok out of order.

Two teeth. No DNA. You can only infer so much from that little. We know about the Denisovians, because we could get DNA from them (thankfully they were not beyond the age where DNA can be extracted. DNA is after all not stable). So yeah the teeth were from something that MIGHT be an ancestor. OR might be a branch that had nothing to do with us. There is not enough to make any comment beyond "cool another primate of some sort". IF they find more bones it might rewrite things. As it stands the most likely scenario is that Homo sapiens came out of Africa and intermingled with at least two other members of the genus Homo. The fossils indicate this ( the out of Africa bit) and the DNA shows this.

I am pretty sure you did not understand the point. But ok you understood it fine. Therefore you should be fine with the idea of mt-Eve.

I did not imply you were a creationist, I said you mentioned something that creationists try to use to disprove evolution.

My degrees are a PhD and Bsc(Hons) in Chemistry, Post graduate diplomas in (1) Bioinformatics (focusing on Synthetic lethals for cancers, but trained in evolutionary genmoics) and (2) Hazard Assessment and Management. Plus a business Masters. I work in the Pharmaceutical industry. Since we are talking about degrees

We use the molecular clock to our advantage in bioinformatics. No its not fine tuned. I will grant that, however it gels well with the other evidence. Its how one constructs the phylogenetic diagrams (aka "trees of life") that people seem to need to see (as opposed to the way bioinfomaticists tend to look at the data).

Again I am still not sure what your point is with "the decay of genes".

a reply to: Noinden

How would you know a modern human from say China from a separate line existed if they died off 250kya ago from disease or genocide?

a reply to: Phantom423

Well different groups of Hominids would be differnt species, if you mean Neanderthals, Denisovians, and archaic Homo Sapiens? Same genus, different species. I feel the problem here is we assigned species based off of fossils (before we understood or could analyze DNA). We can't get DNA from everything, thanks to DNA falling apart over tens of thousands of years. However its a good tool.

But too your point. The statistical evidence (based of of mt DNA and Y Chromosomal DNA) shows that the group with the most variance (and thus the oldest) is sub Saharan Humans. If its the oldest, logic tells us its where we came from first. It gets complex with interbreeding with Neanderthals, and Denisovians (and Neanderthals with Denisovians) as well as at least one undiscovered Hominid (the DNA shows it, we have no fossils yet, or perhaps ever).

So looking at fossils (oldest sapiens are from Africa) and the DNA, best scenerio is from Africa.

Add in the Toba event, and any diseases that caused bottle necks (We can't easily detect any that were pre-written history) one gets a useful tool of there being a single source of mt-DNA surviving, and the same for the Y-Chromosome.

We don't have a "first woman" and I could slap Bryan Sykes and other scientists who use the phrase "Eve" to describe the source of all the mt clades (clans) we see today. She's not the first woman, just the woman who's mt-DNA line survived. But call her Eve, and lo every one goes "first woman". Similarly the temporally distant "Y-Adam".

SO the ONLY significane of mt-Eve is her line is the only one to survive (and then mutate to the other clades (Clans)) we have today. IF you have an interest tread the works of Bryan Sykes (start with the Seven Daughters of Eve, the European mt-Clans).

Does that help? While I don't work in this area (anymore) I love to keep my finger in the pie "

a reply to: luthier

It would not matter, they did not pass their DNA on. the point of all this is what we see today. What we see today, is that all humans have the majority of their DNA originating from Sub Saharan Africa. There is admixture with Neanderthals, Densisovians, and evidence of at least one unknown hominid (obviously genus Homo)) above the Sahara.

Thus any modern Humans (and by this you are meaning Homo sapiens right?) that got wiped out, don't count. They did not contribute to the DNA of the species today.

Now given we breed with Neanderthals (Homo neanderthalensis) and Denisovians (Homo sp. Altai,[1] / Homo sapiens ssp. Denisova) as DNA analysis indicates, along with a good chance of a third member of genus Homo, there is little chance we wiped out these "Chinese modern humans" . There is also a very low chance that these Chinese humans (which one assumes you are saying evolved to modern human individually?) were identical enough to all other Human sapiens to be considered the same species.

a reply to: Noinden

I think you miss what I am saying. I am not sure the DNA is the important factor in the evolutionary process particularly from 100's of thousands of years ago.

It seems that older fossils are found in south Africa that place homo sapien older than mtdna eve. What does that mean in your opinion as far as human evolution? Possibly 150kya older than our branch of genes.

Are you saying that the genes of another older line that died off (where as the mtdna of the bottleneck in "eve") couldn't have just disappeared by not being part of the mating process for 100's of thousands of years?

Technically isn't it possible the original evolutionary homo sapien was actually just bread out of that time?

These are again just pondering. I am not having trouble with mtdna eve. Just I don't think we have close to the story. Like how did those footprints end up in 5 million year old mud? Or are the teeth from a hominid.

I am certainly not saying ooa is wrong. I just want to find out if anything else is possible.

I mean we thought a door was solid until we figured out it was mostly empty space.

a reply to: luthier

Why would DNA not be important? DNA is how we pass on traits. Evolution is the mutation of DNA. Thus how can it not be important. Care to show me your point? OR is this a personal beleif of yours?

Yeah it is clear you do not understand mt-Eve.

One more time. Slowly

She was not the first woman. Not even in our species (most likely). She is the progenitor of the surviving mitochondrial clades.

Do you understand what mt DNA is? No I am serious, not snarking.

Because we are only talking about SNPs (single nucleotide polymorphisims) in non-coding parts of the mitochondria. Which is not part of our nuclear DNA (our genes). We measure these as they reliably change, not becuase they denote big differences.

So no you did not get my point. Please go read a bit more about what mt-Eve and Y-Adam are.

a reply to: Noinden

Oh boy, your right I have no idea....

What you have done however is ignore every other question I had and seem to be focused on your point.

Can you show me the DNA of human frim south Africa from 300kya ago?

Oh well.

a reply to: Noinden

We don't have a "first woman" and I could slap Bryan Sykes and other scientists who use the phrase "Eve" to describe the source of all the mt clades (clans) we see today. She's not the first woman, just the woman who's mt-DNA line survived. But call her Eve, and lo every one goes "first woman". Similarly the temporally distant "Y-Adam".

That makes more sense to me. It sounds more like the original gene pool which survived whatever catastrophes the other groups did not.

As to Neanderthals, are they or are they not human? I've read several articles which suggests that anthropologists don't agree. If they're not human, then what are they? It's my understanding that Africans don't carry Neanderthal genes because they never interbred with them. So they must have evolved independently of Africans. I find the topic quite confusing in a lot of aspects. Thanks for the info.

a reply to: luthier

I wonder if DNA has been extracted from this find in South Africa:

www.washington.edu...

It's definitely a puzzle. I'll probably stick with my opinion that the Annunaki were dropped on to Earth by aliens. The stories are good anyway

a reply to: Phantom423

I agree it's confusing because the data is incredibly limited. Particularly genes since they decay over time.

My point was not to discredit the bottleneck of out current genes but to how we evolved as a whole which is not the debate I ever seem to be able to get.

How did we evolve. Surely the mtdna during one bottle neck does not detail the actual process like going out and adapting to new environmentsite, learning new skills, and then exchanging information.

a reply to: Phantom423

As a philosopher I have considered the possibility of the design/er.

For one it exist(design/code). Otherwise we couldn't decode it.

For another to create symmetry in cosmology from non design you end up with super symmetry which is every bit as strange as Gods to get your head around and doesn't disprove a design anyhow.

I often get scientists who say you obviously don't get it.

It's the same with logic for me as a philosopher. Some people don't like to use it when there isn't direct evidence, and mistake a lack of evidence in a hypothesis (with very little artifact of evidence) for a failure of possibilities or even probability in some cases.

I often think about a human 150kya could be most likely raised from birth to work for Boeing if you had a time machine.

Or we are close to beING able to inject memories in an ape and give them instant language.

In my opinion (and controversial) these type of things actually bring a designer possibility closer to reality. I don't mean it is reality just that the idea of a superior race of intiligent being creating another and then also being effected by evolution which is a force I view like gravity.