History Community ~ All Empires Homepage


This is the Archive on WORLD Historia, the old original forum.

 You cannot post here - you can only read.

 

Here is the link to the new forum:

  FAQ FAQ  Forum Search   Events   Register Register  Login Login

Forum Lockedhuman origin debate (out-of-africa?)

 Post Reply Post Reply Page  <1234 5>
Author
Beylerbeyi View Drop Down
Chieftain
Chieftain
Avatar

Joined: 02-Aug-2004
Location: Cuba
Status: Offline
Points: 1359
Post Options Post Options   Thanks (0) Thanks(0)   Quote Beylerbeyi Quote  Post ReplyReply Direct Link To This Post Posted: 04-Jan-2009 at 14:29
Quote Some multi-regionalists are against out-of-Africa because the theory can be linked to religous ideas. Most religions claim we have the same original ancestors and spread from them.
Interesting. But even the broken clock shows the right time twice a day. Religious nutters are similarly right about this. 
Always try to be as radical as reality itself. - Lenin
Back to Top
Boreasi View Drop Down
Consul
Consul
Avatar

Joined: 15-Sep-2006
Location: Norway
Status: Offline
Points: 300
Post Options Post Options   Thanks (0) Thanks(0)   Quote Boreasi Quote  Post ReplyReply Direct Link To This Post Posted: 17-Jan-2009 at 06:28
Originally posted by Beylerbeyi Beylerbeyi wrote:

Quote Some multi-regionalists are against out-of-Africa because the theory can be linked to religous ideas. Most religions claim we have the same original ancestors and spread from them.
Interesting. But even the broken clock shows the right time twice a day. Religious nutters are similarly right about this. 


Funny point. The rare in this case is that the paradox reaches even further.

Both the "single-origin-hypothesis" and the "multi-regional-theory" have proven some points, of which some concerns the time-scales for the respected "Uit-of-Africa-theory".

The present evidences points to a single origin of the "naked, speaking ape" called the human specie. The timing seems awfully of though, since both the Java-man and the Peking-man have had a say in the case of the East -Asian populations.

There are no clear paralell ("proto-type") found in India, but it is obvious that the Indoneian, Chineese and Indian peoples are distinctivey and "inherrently" different from each other. The discrepancy to Africans are also obvious and the word "race" have been the traditional way to adress these clear, physiognomic characteristics - that makes itpossible to distinguish different kinds of people - by both appearance and language.

(The word "race" used to be a pretty neutral term, associated with "recogition", "description" and "facination" - rather than "politics", "prejudism" and "racism".)

To explain the history of the variations of the human specie, as adaptions to specific climates and continents - we will also need a bit more than a daft 1000 generations from A common origin as a specie. Just think about the time it will take to transfrom the entire chromsomes of an African before his body and temper is completly adapted to the macro- and micro-levels of the Arctic hemisphere? Moreover, to explain the arctic population of the palefaces you may also need a complete arctic biosphere in place - first...

In 1998 traces from a dwelling-site of modern man was discovered at the Pechora-bassin, straigth north of Moscov.  Among other tissues a carvd bone of mammoth was found and dated - to be 36.000 Cyr BP. It seems that the guys from Africa have already been predated - long before they would have a chance to have mutated into straigth-haired, blonde, blue-eyed mutatant - normally called "Caucasian".

It seems that these "Caucasians" had another history - in some god-forsaken refugia, where they were left in isolani for enough generations to make them all adapt to an high-arctic climate, where the sun takes a nap during the entire month of midwinter. As we know this pculiar climate-zone have developed a complete set of plants and animals that are nowadays named "arctic" or "sub-artic". A characteristic of several arctic animals are white fur - or skin. The characteristics of the "palefaces" have obviously been developed to enhance the efficency of absorbing the sunligth - as it returned with the spring.

From the demography of the present world we can still identify - and thus characterize - the variety of the major etnic groups. So - that's our herritage, as a specie - and nothing to worry about,  but rather to care about. Since the awareness of our etnic roots along with our mother-tongues seen to forms the basic tools in our personal quests for identity and purpose in life. This can be easily observed in the years of childhood and youth - when our personalities are formed...

Thus it can be learned that the mythic part of some religions - claim we're all from one and the same couple of A First Man and Woman. Consequently we are one and the same specie and thus, duely related to each other. Since the genetic expertise seems to agree we have to ask how this correct version to our orgin could be preserved - as a story - from early man to Moses?!

The proto-caucasians seem to come out of their refugia at the end of the ast ice-age, 10.000 years ago. Since then they have poplated the arctic and sub-arctic climate-zone, spread agriculture and connected to all the tropical populations - that existed as different races on different (sub-) continents already since "time orgin".

We still do not know when or where this "time origin" happened. Only to explain the latest branch - the "icemen" of the north - and the Caucasian metamorfism, we have to 
go back at least to the warm climate of the Eem-period (120.000 BP). That may explain a possibile origin of "a limited group getting isolated", since there are three different sites from this period found in Scandinavia. Consequently we have started to suspect that the "climatic refugia" - that led to the Caucasian kind and culture - may have happened at the top of the Gulf-stream in those days;  the shores of Scandinavia and the Baltic Sea...

In retrospect I think its ample to claim that the "origin of man" was tropical. Thus it is clear that we shall look for the "first origin" in a tropical/temperated circumstance. But it doesnt have to be Africa - and it is definitly more than 1 million years ago, since it produced offsprings in both Spain and China about that time. Me thinks Spencer Wells still have some serious reconsiderations in the waiting...


 
Be good or be gone.
Back to Top
calvo View Drop Down
General
General


Joined: 20-May-2007
Location: Spain
Status: Offline
Points: 848
Post Options Post Options   Thanks (0) Thanks(0)   Quote calvo Quote  Post ReplyReply Direct Link To This Post Posted: 17-Jan-2009 at 14:55
I'd like to make one point clear: human evolution did not occur in a continuous straight line, but rather in he form of a bush with dozens of branches and twigs. By DNA testing of the world's population today, it seems like that we are all descended from one very small twig of the bush; with all the rest of the hominid branches and twigs gone extinct.
 
From 4 million years ago onwards, apes already began walking on 2 feet. Numerous biological branches had emerged in the long journey evolution from ape to man, but most of these did not evolve into modern humans.
 
It is true that hominid remains from 1 million years ago had been found in China, Europe, and Central Asia; most of them belonging to homo-erectus species; yet these early man-like creatures were NOT the ancestors of the modern populations in these regions.
Instead, it looks like that all human beings descended from a single migration out of Eastern Africa as recent as 80,000 years ago; while all the hominid species already living in these parts of the world had faded away.
 
THe "Out-of-Africa" theory has been backed-up mostly by DNA testing; as gene mutations leave a mark on the DNA; and the descendants of the "mutants" inherit these marks.
If 2 people share the same mutation mark on the DNA, then it would mean that they had once shared an ancestor. Scientists could also calculate how many generations ago this mutation took place; and thus we could detect how many generations ago these people shared an ancestor.
By DNA mutation mark testing, it has been demostrated that ALL human beings everywhere in the world shared the same female ancestor between 200,000-500,000 years ago; and the same male ancestor between 60,000 - 90.000 years ago.
And both mutation marks seem to have occured within Africa.
 
It has also been detected that non-Africans have only a very small fraction of the genetic diversity of Africans; which suggest that those who left Africa were only a very small fraction of the population inside Africa at the time.
 
 
 
 
 
 
 
Back to Top
calvo View Drop Down
General
General


Joined: 20-May-2007
Location: Spain
Status: Offline
Points: 848
Post Options Post Options   Thanks (0) Thanks(0)   Quote calvo Quote  Post ReplyReply Direct Link To This Post Posted: 17-Jan-2009 at 14:58
Originally posted by calvo calvo wrote:

By DNA mutation mark testing, it has been demostrated that ALL human beings everywhere in the world shared the same female ancestor between 200,000-500,000 years ago 
 
Well, I actually meant 120,000 to 150,000 years ago.
However, forensic evidence suggest that African human beings 200,000 years ago could already be considered fully-fledged homo-sapiens.
Back to Top
Boreasi View Drop Down
Consul
Consul
Avatar

Joined: 15-Sep-2006
Location: Norway
Status: Offline
Points: 300
Post Options Post Options   Thanks (0) Thanks(0)   Quote Boreasi Quote  Post ReplyReply Direct Link To This Post Posted: 18-Jan-2009 at 02:32
Originally posted by calvo calvo wrote:

Originally posted by calvo calvo wrote:

By DNA mutation mark testing, it has been demostrated that ALL human beings everywhere in the world shared the same female ancestor between 200,000-500,000 years ago 
 
Well, I actually meant 120,000 to 150,000 years ago.
However, forensic evidence suggest that African human beings 200,000 years ago could already be considered fully-fledged homo-sapiens.



The sequencing of various haplotypes have brougth us endless rows of "limbs" and "branches" on the the human "haplogroup-three".  Modern genetics have developed into a high-tech artistery, where the major structures and sequences of the human gene-pool seem to be mapped.

1. How to determine the AGE of genetic structures?

So far the bio-molecular expertise havent found a way to ask the specific branch or limb itself. Thus the time-lines of modern genetics are made by COMPARING major abrivations in the gene-structure with KNOWN historical incidents - that include ancient etnic groups spreading or migrating before they developed into the "etnic and genetic characteristics" we may find in todays populations...!

Consequently the time-lines etsablished by present geneticians are STILL based on the theories established by the interpretations of the archaeological material from the last 10.000 years, mainly.

2. Paleolitic time

Then the problem is that - in spite of a strong progress dring the last decade - modern archeology still have a relatively poor knowledge of the time prior to the last ice-age. Conclusively the time-lines, causes and consequences you refer to are still based on speculation...

3. Recycled arguments

 Only under the premiss that the OuA-theory is rigth, will the present suggestions to time-lines be relevant to our origin as a specie. Then it doesn't really prove anything if and when the OuA-theory is "backed up" by the suggested time-lines.

4. Human mutation-rates

The heck of it still is that we don't have any scientific tools that can help to back up the SUGGESTED timelines of "mutation-rates" for the human being. The dna-molecules can reveal its variety of structure - but neither the time of its "chromosomal birth" nor its age can be measured technically.

5. Assesments and time-lines

Thus the archeological time-lines are used as a basis for the method of ASSESMENT used to "measure" the "general age" of various haplogroups. To gain a parameter for the time the various haplogroup-threes have needed to grow into the various mutations/sub-clads, the geneticians HAVE HAD to confer with the "up-dated" views of present historians. Thus the entire edifice still rests on the major time-lines produced by modern archeology.

As long as this "time-line" of human genetics rests entirely on the axiom from archeology you cant use an assumed (genetic) "time-axis" to constitute, correct or complete any other time-line than the one given by the same archeology.

6. Diversification and diversity

The indepth study of the regional differences within our gene-pool, pluss the relationship between the ancient Piking-man and th present Chineese, points to a time of diversification between the Chineese and the Indians (for instance) that are far older than 60.000 years. According to the "multi-regionalists" there were regional populations and cultures on several continents more than 800.000 years ago.

7. An Ancient Common Origin

What the mulit-regionalists may not say is that we had a COMMON origin to all these various groups of "proto-humans".  The origin, though - of the first speaking monkeys - is more than a millin years old. Thus the diversity of the socalled "races" of this planet is also more than a million year old - even if the gene-flow have managed to level the scores remarkably since the travel, trade and migrations started, some 10.000 years ago.
 
Still the remarkable diversity in etnic characteristics and regional gene-pools still tells us that the difference between aboriginals, amazon-indians and eskimos are far more than 40.000 years old. Thats where the multi-regionalists are rigth.

Today the hypothesis of a common origin of mankind seems to be conlusively proven. Though - that it happened in Africa only 100.000 yrs ago seems less and less likely. The roots of mankind seem to be far older than that...



Edited by Boreasi - 18-Jan-2009 at 04:27
Be good or be gone.
Back to Top
Bulldog View Drop Down
Caliph
Caliph
Avatar

Joined: 17-May-2006
Location: United Kingdom
Status: Offline
Points: 2775
Post Options Post Options   Thanks (0) Thanks(0)   Quote Bulldog Quote  Post ReplyReply Direct Link To This Post Posted: 18-Jan-2009 at 03:06
Were all descended from Adam and Eve Smile or as scientists put it, were all descended from one female and guy if we go back far enough.
      “What we do for ourselves dies with us. What we do for others and the world remains and is immortal.”
Albert Pine

Back to Top
Akolouthos View Drop Down
Immortal Guard
Immortal Guard
Avatar

Joined: 24-Feb-2006
Location: United States
Status: Offline
Points: 2096
Post Options Post Options   Thanks (0) Thanks(0)   Quote Akolouthos Quote  Post ReplyReply Direct Link To This Post Posted: 18-Jan-2009 at 03:15
Originally posted by Bulldog Bulldog wrote:

Were all descended from Adam and Eve Smile or as scientists put it, were all descended from one female and guy if we go back far enough.
 
I guess I just don't find this surprising. I've often found it offered as "proof" of a variety of religious opinions, but I suppose it is something that I just assume. If we are here, we had to have had a pair of genetically similar parents, who were capable of breeding with each other in order to produce our ancestors. I don't find it all that shocking.
 
And I know you don't either, Bulldog; I was just hoping someone could explain to me why there is such a hubbub over what I view as a completely logical deduction.
 
-Akolouthos
Back to Top
SearchAndDestroy View Drop Down
Immortal Guard
Immortal Guard
Avatar

Joined: 15-Aug-2004
Location: United States
Status: Offline
Points: 2733
Post Options Post Options   Thanks (0) Thanks(0)   Quote SearchAndDestroy Quote  Post ReplyReply Direct Link To This Post Posted: 18-Jan-2009 at 03:59
Only thing is that the two of them never met. And MtDNA Eve is Y-Adam's great great great...well etc............. grandmother. MtDNA Eve is said to lived about 120,000 years ago, while Y-Adam is said to live around 40-60,000 ago if I remember right.  
"A patriot must always be ready to defend his country against his government." E.Abbey
Back to Top
Boreasi View Drop Down
Consul
Consul
Avatar

Joined: 15-Sep-2006
Location: Norway
Status: Offline
Points: 300
Post Options Post Options   Thanks (0) Thanks(0)   Quote Boreasi Quote  Post ReplyReply Direct Link To This Post Posted: 18-Jan-2009 at 04:31
Originally posted by SearchAndDestroy SearchAndDestroy wrote:

Only thing is that the two of them never met. And MtDNA Eve is Y-Adam's great great great...well etc............. grandmother. MtDNA Eve is said to lived about 120,000 years ago, while Y-Adam is said to live around 40-60,000 ago if I remember right.  


So who did mtDNA-Eve reproduce with - in order to get new "Eves", while Y-Adam is in the making?! And what happened to Eve jr.s eventual brothers?!
Be good or be gone.
Back to Top
SearchAndDestroy View Drop Down
Immortal Guard
Immortal Guard
Avatar

Joined: 15-Aug-2004
Location: United States
Status: Offline
Points: 2733
Post Options Post Options   Thanks (0) Thanks(0)   Quote SearchAndDestroy Quote  Post ReplyReply Direct Link To This Post Posted: 18-Jan-2009 at 04:51
Another human male. It's what scientist have come to a conclusion to by studying our DNA. Just as they can look at people from Mongolia and find that they have what is believed to be Ghenghis' genetics. Y-Adam is just the last human male that EVERY human has as a common ancestor, it doesn't mean other lineages didn't exist before that point, because they did.
So now alot of Mongolians have Ghenghis as their ancestor. If every other human dies right now, besides those with his genetic link, then he becomes the new Y-Adam, and that MtDNA Eve still exists, yet Ghenghis would have never known her.


Edited by SearchAndDestroy - 18-Jan-2009 at 04:56
"A patriot must always be ready to defend his country against his government." E.Abbey
Back to Top
Boreasi View Drop Down
Consul
Consul
Avatar

Joined: 15-Sep-2006
Location: Norway
Status: Offline
Points: 300
Post Options Post Options   Thanks (0) Thanks(0)   Quote Boreasi Quote  Post ReplyReply Direct Link To This Post Posted: 18-Jan-2009 at 05:06
So there was still a "proto-Adam" contemporary with "Eve" - 120.000 yrs BP?!

Thn what happened 60.000 BP when no more than ONE man, from the entire population of human beings in the world, were able to reproduce...?!

What happened to all the others?!
Be good or be gone.
Back to Top
SearchAndDestroy View Drop Down
Immortal Guard
Immortal Guard
Avatar

Joined: 15-Aug-2004
Location: United States
Status: Offline
Points: 2733
Post Options Post Options   Thanks (0) Thanks(0)   Quote SearchAndDestroy Quote  Post ReplyReply Direct Link To This Post Posted: 18-Jan-2009 at 05:55
Well, this in away explains evolution, in that genetics change from random mutations. I may have the exact same Y as my father and alot of generations back,(if I understand genetics right thus far) but if my son has a mutation, now if his children  children carry a new Y that can be marked. And if all lineages die except for my sons, his lineage becomes the last known Y as explained above.
 
So, my guess is there may have always been a leap frog, that the Y-Adams and MtDNA Eves at different times would have never met. And following evolution, the only time that their was ever a shared parent could have been a cell that just split itself.
 
Look at it this way. One cell created all life, and different species evolved from it over time. Even the cells may have started their own lineages much like described above. But in transitional periods of species, which would last millions of years, they'd still be able to breed with each other. At some point a Donkey and Horse had a common ancestor that was neither one of them, and over time they kept changing, most likely due to isolation of the two species. Now a days they can breed together, but their offspring have no fertillity. Another couple million years(which cosmicly could be related to maybe a couple minutes in away) they won't be able to breed, and will probably look alot different then they do now. We also have a common ancestor with Chimps, followed by with Chimps other great Apes, then the great Apes as a group share a common ancestor with monkeys, then that group with other primates and so on.
 
So, if there was a common ancestor for humans had were a Y-Adam and MtDNA Eve both knew each other, the earliest probably would have been the ancestor of all primates. Though that is probably just as unlikely.
"A patriot must always be ready to defend his country against his government." E.Abbey
Back to Top
calvo View Drop Down
General
General


Joined: 20-May-2007
Location: Spain
Status: Offline
Points: 848
Post Options Post Options   Thanks (0) Thanks(0)   Quote calvo Quote  Post ReplyReply Direct Link To This Post Posted: 18-Jan-2009 at 10:29

Boreasi,

Have a look at this web page. It is from national Geogaphic and it presents human genotype analysis in great scientific detail:
 
I have explained to you in the previous post regarding the general technique, about detecting how many generations ago a mutation took place.
For example, if you and I share a mutation marker on the Y Chromozone 500 generations ago; then if MUST mean that 500 generations we still shared the same ancestor.
How many years ago was 500 generations? We cannot know for sure, but we could make an estimate of an average generation of 20-25 years.
By taking a sample of ALL the world's population today and comparing the mutation markers; it has been found that we ALL shared a same female ancestor around 120,000 years ago and a same male ancestor around 60,000 years ago.
 
I don't know where you got your info on the 80,000 separation of East and South Asians from, but I don't seem to find any sources to back up this claim anywhere.
Once I tell you again that the "Pekin man" in China and the "Neanderthal" in Europe were hominid species, but by analysing their DNA, they WERE NOT the ancestors of modern Europeans and Chinese.
Instead, modern Europeans and East Asians are more related to modern Africans than to any of these archaic homonid species in the same region.
 
The fact that we all descend from an "X-chromzone Eve" 120,000 years ago does not mean that she was the only woman alive. She probably lived in a community of thousands of people and mated with whoever.
Nevertheless, through the passing of generations, only genes that descend from her have survived natural selection; while all the others had simply faded out.
 
I hope my explaination is clear to you.
 
 
Back to Top
Bulldog View Drop Down
Caliph
Caliph
Avatar

Joined: 17-May-2006
Location: United Kingdom
Status: Offline
Points: 2775
Post Options Post Options   Thanks (0) Thanks(0)   Quote Bulldog Quote  Post ReplyReply Direct Link To This Post Posted: 18-Jan-2009 at 14:15
So our common female ancestor waited 60,000 to reproduce, humans must have lived a long time in those days.
      “What we do for ourselves dies with us. What we do for others and the world remains and is immortal.”
Albert Pine

Back to Top
calvo View Drop Down
General
General


Joined: 20-May-2007
Location: Spain
Status: Offline
Points: 848
Post Options Post Options   Thanks (0) Thanks(0)   Quote calvo Quote  Post ReplyReply Direct Link To This Post Posted: 18-Jan-2009 at 14:41
Originally posted by Bulldog Bulldog wrote:

So our common female ancestor waited 60,000 to reproduce, humans must have lived a long time in those days.
 
It does not have to be so at all.
She reproduced with contemporary males and had numerous offspring. Only that these contemporary males did not contribute to the ancestry of the modern human population.
In my previous post I explained the mechanism.
"Eve" was not the only human female alive at the time, nor was "Adam" the only male alive at his time; only that the genotypes of other individuals had faded away over the generations; but theirs had survived and contributed to the base of all modern human genotypes.
 
Check out the National Geographic site, there is an interractive diagram of mutation and genetic drift.
 
Biologically there is no obvious dividing line between one "species" and another kindred species. Officially, the definition of the word "species" is "able to mate and produce fertile offspring". When 2 groups of the same species live separately for a long time they would develop differences; and at one point the differences would become so big that they could no longer mate; then they cease to become members of the same species.
 
Nevertheless, there is an "ambiguous zone" as there were a few generations during which some members of the 2 groups could still mate and produce fertile offspring, and others could no longer do so.
 
We cannot say at what generation did humans evolve from hominids to homo-sapiens; but it is estimated that 200,000 years ago in eastern Africa, anatomically modern human beings had already existed. This meant that if we caught a time machine back then we could probably mate with them Wink and produce fertile offspring.
 
However, despite that human beings existed from 200,000 years ago onwards, not all of them have descendants today. There was one female common ancestor, and one male common ancestor of all living human beings today; and they lived at 120,000 years ago and 60,000 years ago.
 
I hope I have clarified the issue.
 
 
 
Back to Top
Bernard Woolley View Drop Down
Pretorian
Pretorian


Joined: 11-Jun-2008
Location: Canada
Status: Offline
Points: 154
Post Options Post Options   Thanks (0) Thanks(0)   Quote Bernard Woolley Quote  Post ReplyReply Direct Link To This Post Posted: 19-Jan-2009 at 05:35

It must be remembered that the "Eve" and "Adam" we're talking about here are not actually individual people, but genetic markers.

A useful analogy for mtDNA Eve and y-chromosome Adam I've heard used is to think of them as family names. In some communities that remain isolated (at least genetically) for many generations, eventually everyone ends up with the same family name. This happens not because they all had the same name to begin with, but because over time, as some families have more children than others, or adopt the children of other families, or (assuming the names are passed down patrilineally) have a higher proportion of boys than other families, one family name ends up marking the entire community.

The reason why the mtDNA and y-chromosome markers don't match up to a single contemporaneous pair is that they are equivalent to two family names, one passed down through men and the other passed down through women. Both markers were passed down through the chance elimination of competitors, until one male marker marked all males and one female marker marked all females. Because the dying out of competing names is a very chancey process, there is a low probability either that the successful markers would happen to be those of a coupled man and woman, or that it would happen to take the same amount of time for both processes to finish.

It's probably also worth pointing out that y-chromosome markers seem to multiply and die out more often. This is probably because the probability of some men having many more children than other men is higher than the probability of some women having many more children than other women.

Back to Top
gcle2003 View Drop Down
Immortal Guard
Immortal Guard
Avatar

Joined: 06-Dec-2004
Location: Luxembourg
Status: Offline
Points: 7011
Post Options Post Options   Thanks (0) Thanks(0)   Quote gcle2003 Quote  Post ReplyReply Direct Link To This Post Posted: 19-Jan-2009 at 12:15
Again, that we may all have a common ancestor doesn't prove (or even indicate) there was only one common ancestor (of either sex - I don't just mean we need a male and a female). The odds are very heavily in favour of that mitochondrial Eve having siblings and half-siblings, even an identical twin. Or for that matter, cousins that could certainly interbreed with her, if male, or produce similar offspring if female and paired with the same male.
 
I also, unlike Search and Destroy (most of whose post I agree with) do not believe that all life came from a single cell. I see no reason to believe that at all (and not just because life originally was probably not cellular). Whatever set of circumstances produced the first life or the first cell is very likely to have created many of them more or less simultaneously.
Citizen of Ankh-Morpork
Never believe anything until it has been officially denied - Sir Humphrey Appleby, 1984.
Back to Top
Boreasi View Drop Down
Consul
Consul
Avatar

Joined: 15-Sep-2006
Location: Norway
Status: Offline
Points: 300
Post Options Post Options   Thanks (0) Thanks(0)   Quote Boreasi Quote  Post ReplyReply Direct Link To This Post Posted: 20-Jan-2009 at 02:10
"To create a new specie you need two offsprings from the same parental origin able of sucessful reproduction".

Which means that the monkey and the missig link made children that was able to speak
- and to reproduce with each other.

That's what this question is about; when did the first male AND female occur - able to produce linguistic sounds, to accurately and clearly express focused thougths, - as well as associations and intents?


Your speculations and theories can't start with bending that very pre-requisite for creating a new primate specie - such as the human being. The above suggetion about two distinctly different creations (separated by 60.000 years) is a mere suggestion, created to explain an anomaly discovered within the research on the present DNA. That does NOT mean that this theory is - in any way - scientifically proven but a mere suggestion...  

Thus I also commented (above) on the analyzis and maps doen by Spencer Wells and the team at NG. As a growing number of genetic and archeological results differ or (even) disagree with the OoA-theory, it's clear that Wells & Co still have some principal RE-considerations to do.  




Edited by Boreasi - 20-Jan-2009 at 02:48
Be good or be gone.
Back to Top
konstantinius View Drop Down
General
General
Avatar

Joined: 22-Aug-2006
Status: Offline
Points: 762
Post Options Post Options   Thanks (0) Thanks(0)   Quote konstantinius Quote  Post ReplyReply Direct Link To This Post Posted: 28-Jan-2009 at 08:09
I just went over my notes from last semester's "Human Fossils Practicum", San Francisco State University, Dr. Mark C. Griffin:
--The conclusion is based on the assumption that African populations have a higher heterogeneity, i.e. more ancient.
--Suggested date is 290,00-140,000 BCE.

Problems with Cann's methodology;

--Cann based her "mitochondrial Eve" theory on a VERY small sample, n=147. That in itself is a statistical problem, i.e. sample is not representative of the population.
--African sample consisted of 18 African-American and 6 indigenous Africans. This is biased, i.e. African-American DNA is high in 'white' DNA--Jefferson apparently was not the only one to do you-know-what.
--We still do not know how fast mtDNA mutates. If we are not positive about the speed of mutation we cannot ascertain biodistance with confidence.
--We are not certain that fathers cannot pass mtDNa on their side.

Relethford (1995) suggests that "daughter" populations will have substantialy less diversity than parent populations. So 'age' of population does not depend on variation.

Templeton (2002):
--Africa has played a dominant role in modern human DNA
--At least two major expansions (probably more) out of Africa after radiation of H. erectus.
--Recurrent gene flow is supporting Brauer's hypothesis of partial replacement.
--Populations probably expanded with interbreeding, not complete replacement.

Regional continuity is supported by the fossil record as well:
--Skhul 1 at Qafzeh (100-90 kya) displays full modern features with some archaic features.
--Predmost, Czech Rep: 26,000 yo Neaderthal features together with more derived, gracile features, as well as completely modern humans
--Asia: the great antiquity of some traits (shovel-shaped incisors, occipital bun) suggest regional continuity. This local persistence of archaic features in modern populations is NOT explained well by the replacement theory: it would mean that the SAME mutations have to appear TWICE, an evolutionary improbability.

Personally, as a bioarchaeologist-in-training, I cannot simply discount the fossil record that seems to point to partial, not complete, replacement. Also, Cann has comitted methodological errors that should not be overlooked. Do not get me wrong, modern humans DO appear in S. Africa 120-100 kya (Klasies River Mouth, Omo Kibish, Border Cave). However, and in contrast to the fossil record, loci controlling protein structures show that African populations exhibit the greatest variation and are most distinct than others, i.e. older as expected in the "Out of Africa" theory.  
" I do disagree with what you say but I'll defend to my death your right to do so."
Back to Top
konstantinius View Drop Down
General
General
Avatar

Joined: 22-Aug-2006
Status: Offline
Points: 762
Post Options Post Options   Thanks (0) Thanks(0)   Quote konstantinius Quote  Post ReplyReply Direct Link To This Post Posted: 28-Jan-2009 at 08:18
I tend to support Wolpoff's Multiregional Hypothesis based on the fact the humans have maintained genetic continuity and species cohesiveness. There are multiple, not one, migrations out of Africa, beginning of course with H. erectus. Genetic drift quarantees persistence of regional populations that are further away from the 'center' of radiation (Africa). In these cases, interbreeding takes place; elsewhere replacement is possible. Big question: does interbreeding happens with Neaderthals? Recent DNA extracted from nead. says no. But in Asia local populations persist.
" I do disagree with what you say but I'll defend to my death your right to do so."
Back to Top
 Post Reply Post Reply Page  <1234 5>
  Share Topic   

Forum Jump Forum Permissions View Drop Down

Forum Software by Web Wiz Forums® version 11.10
Copyright ©2001-2017 Web Wiz Ltd.

This page was generated in 0.078 seconds.