Human origins in Africa???????

Question

Are there any other credible theories out there? The PC theory of us all trotting merrily out of Africa is waring thin &, I believe, grown rather silly. It simply makes no sense. So what other theories have scientists come up with for us to have a look at?

Answer 1

You see it quoted so often that you’d be mistaken for thinking everyone agrees on the ‘we are all descended from a small group of Africans that left the continent 70,000 years ago’.

It’s something that pleases the liberal media, not something geneticists agree on. Ive seen research items other than these rip into the ‘out of Africa theory’ before.I’d like to point out (ad nauseum) that human remains have been found in China over 100k old, making the date part ridiculous. There are remains of modern humans 162k old in Morocco, and 125k old in Israel.

I recommend a careful read of this link...

http://home.entouch.net/dmd/hegene.htm

It’s an extremely thorough hatchet job on the ‘Out of Africa’ theory, showing the evidence against it better than I ever could.

A 'mostly out of Africa' is a lot more likely.

http://www.pnas.org/cgi/content/abstract...

X chromosome evidence for ancient human histories

Eugene E. Harris and Jody Hey*

Diverse African and non-African samples of the X-linked PDHA1 (pyruvate dehydrogenase E1 subunit) locus revealed a fixed DNA sequence difference between the two sample groups. The age of onset of population subdivision appears to be about 200 thousand years ago. This predates the earliest modern human fossils, suggesting the transformation to modern humans occurred in a subdivided population. The base of the PDHA1 gene tree is relatively ancient, with an estimated age of 1.86 million years, a late Pliocene time associated with early species of Homo. PDHA1 revealed very low variation among non-Africans, but in other respects the data are consistent with reports from other X-linked and autosomal haplotype data sets. Like these other genes, but in conflict with microsatellite and mitochondrial data, PDHA1 does not show evidence of human population expansion.

http://mbe.oxfordjournals.org/cgi/conten...

Abstract

The human RRM2P4 pseudogene has a pattern of nucleotide polymorphism that is unlike any

locus published to date. A gene tree constructed from a 2.4 kb fragment of the RRM2P4 locus

sequenced in a sample of 41 worldwide humans clearly roots in East Asia and has a most recent common ancestor ~2 million years before the present. The presence of this basal lineage exclusively in Asia results in higher nucleotide diversity among non-Africans than Africans. A global survey of a single nucleotide polymorphism that is diagnostic for the basal, Asian lineage in 570 individuals shows that it occurs at frequencies up to 53% in south China, while only one of 177 surveyed Africans carries this archaic lineage. We suggest that this ancient lineage is a remnant of introgressive hybridization between expanding anatomically modern humans emerging from Africa and archaic populations in Eurasia.

http://accuca.conectia.es/archaic_genes_...

http://www.genetics.org/cgi/content/abst...

Fossil evidence links human ancestry with populations that evolved modern gracile morphology in Africa 130,000 - 160,000 years ago. Yet fossils alone do not provide clear answers to the question of whether the ancestors of all modern Homo sapiens comprised a single African population or an amalgamation of distinct archaic populations. DNA sequence data have consistently supported a single origin model in which anatomically modern Africans expanded and completely replaced all other archaic hominin populations. Aided by a novel experimental design, we present the first genetic evidence that statistically rejects the null hypothesis that our species descends from a single, historically panmictic population. In a global sample of 42 X chromosomes, two African individuals carry a lineage of non-coding 17.5 kilobase sequence that has survived for over one million years without any clear traces of ongoing recombination with other lineages at this locus. These patterns of deep haplotype divergence and long-range linkage disequilibrium are best explained by a prolonged period of ancestral population subdivision followed by relatively recent interbreeding. This inference supports human evolution models that incorporate admixture between divergent African branches of the genus Homo.

http://www.pnas.org/cgi/content/abstract...

*Howard Hughes Medical Institute, Departments of Human Genetics and Ecology and Evolution, and Committee on Genetics, University of Chicago, Chicago, IL 60637

Edited by Henry C. Harpending, University of Utah, Salt Lake City, UT, and approved October 5, 2006 (received for review August 10, 2006)

At the center of the debate on the emergence of modern humans and their spread throughout the globe is the question of whether archaic Homo lineages contributed to the modern human gene pool, and more importantly, whether such contributions impacted the evolutionary adaptation of our species. A major obstacle to answering this question is that low levels of admixture with archaic lineages are not expected to leave extensive traces in the modern human gene pool because of genetic drift. Loci that have undergone strong positive selection, however, offer a unique opportunity to identify low-level admixture with archaic lineages, provided that the introgressed archaic allele has risen to high frequency under positive selection. The gene microcephalin (MCPH1) regulates brain size during development and has experienced positive selection in the lineage leading to Homo sapiens. Within modern humans, a group of closely related haplotypes at this locus, known as haplogroup D, rose from a single copy 37,000 years ago and swept to exceptionally high frequency (70% worldwide today) because of positive selection. Here, we examine the origin of haplogroup D. By using the interhaplogroup divergence test, we show that haplogroup D likely originated from a lineage separated from modern humans 1.1 million years ago and introgressed into humans by 37,000 years ago. This finding supports the possibility of admixture between modern humans and archaic Homo populations (Neanderthals being one possibility). Furthermore, it buttresses the important notion that, through such adminture, our species has benefited evolutionarily by gaining new advantageous alleles. The interhaplogroup divergence test developed here may be broadly applicable to the detection of introgression at other loci in the human genome or in genomes of other species.

http://www.pubmedcentral.nih.gov/article...

A consideration of the morphological aspects of the earliest modern humans in Europe (more than ≈33,000 B.P.) and the subsequent Gravettian human remains indicates that they possess an anatomical pattern congruent with the autapomorphic (derived) morphology of the earliest (Middle Paleolithic) African modern humans. However, they exhibit a variable suite of features that are either distinctive Neandertal traits and/or plesiomorphic (ancestral) aspects that had been lost among the African Middle Paleolithic modern humans. These features include aspects of neurocranial shape, basicranial external morphology, mandibular ramal and symphyseal form, dental morphology and size, and anteroposterior dental proportions, as well as aspects of the clavicles, scapulae, metacarpals, and appendicular proportions. The ubiquitous and variable presence of these morphological features in the European earlier modern human samples can only be parsimoniously explained as a product of modest levels of assimilation of Neandertals into early modern human populations as the latter dispersed across Europe. This interpretation is in agreement with current analyses of recent and past human molecular data.

Answer 2

No.

Uh "PC theory of us all trotting merrily out of Africa is wearing thin"?

Science isn't PC, it's science. If you're saying you reject science on political grounds, then you can make up anything you like and believe that. It won't be accurate, but I gather you don't care about accuracy, so that shouldn't slow you down.

Whoever told you science says humans "trotted" or were "merry" was lying to you. Mostly likely we talked, and probably not huge distances in one go.

Human life has always had its ups and downs, so it's unlikely they were merry the whole time, though they probably had moments of merriment here and there.

You're thinking that the findings of science, that true things, are silly is of no interrest to anyone, especially scientists.

Since you reject science, you're free to believe any silly thing you like.

Reasonable people prefer believing TRUE things, rather than just making stupid stuff up.

It's pretty clear that humans were first in Africa. That's what science says.

If you hate science for being PC, maybe Pat Robertson would be more your speed.

Answer 3

I don't see what makes it a PC theory?  Fossil evidence leans that way and if you don't know of any other credible theories - why are you questioning the only one which is credible?  Sorry, don't really get your question.

Answer 4

So what is your own credible theory? How did you decided the out of Africa is "thin?'

Just interested. Tossing out years of study and evidence by calling it "PC" and "thin" should require that a very good replacement waiting in the wings.

Put another way, where is your proof? It's really not up to others to defend and explain out of Africa etc.

Answer 5

The fact that no fossil of early humans or any sub-human ever showed any evidence that our earliest ancestors were covered with thick hair , points to the necessity of originating is a warm climate .

That warm climate does not mean Africa , but anywhere along the equator . Many very early human and sub-human fossils are found in the Orient .

Answer 6

Humans originating from africa, I've thought about it and made my mind up and I believe it... What's your problem? why is it wearing thin? it does makes sense fossils n that, and there are no other theories as far as I know...

Answer 7

I think it is stretching credibility to its extremes to blame this on PC thinking!

You are completely free to decide what you want to believe, but I would suggest that there is a wealth of evidence to support our origins being in Africa.

Answer 8

Fossil evidence, and mitochondrial DNA. Pretty hard to dismiss as silly, I'm afraid.

I think perhaps you confuse the genuine paleontology with the ludicrous excesses of the Afro-centric movement, which is not the same thing at all.

Human paleontology suggests that homo sapiens originally evolved in Africa. There is, as I say, a lot of strong evidence for this. I have no problem at all with the notion that we are all Africans!

The Afro-centric movement is pseudo-history, claiming a 'stolen legacy' for black people, and saying that the Greeks and Mesopotamians stole all their learning and culture from Egypt, which in turn got it from Namibia. This is a gross distortion for which there is no credible evidence.

Answer 9

God made us.

Answer 10

Let me ,if you will,impart to you the whole process of the

matter.I speak not for the world.....but to the world.

Not for Scientific research.But through DIVINE

EDUCATION.

Color does not matter in this regard.

The first male and female gender Begain the process

of Humankind.

The sun was the hottest in the east. So it brought forth

dark-skin people of which shade begain all human

existence.All speaking the same language.

THEN,came the separation after the sins of Adam and

EVE.And the unity thereof was challenged by SEEKING

another way.

First,they tried to build a tower to reach into Heaven

as a base of ruler ship.

But it was not to be.For God confused the speech so

that they could understand one another.

And they were scattered abroad over the face of the

whole earth.

Some went this way,and some went that way.

And different places brought forth different colors.And

as each had children they brought forth their own

language.

Different parts of the world have different degrees

of light and sunshine.So some begain red-skin,yellow

skin,pale skin, they that remain in the east,was dark-

skin,some was brown-skin,white-skin,light -skin etc.

And so it was,as it is now with color and languages.

Be not faithless....but believing.

This is not a theory nor make believe.

It is a pure and simple FACT.    Look around you.

Answer 11

There is a certain amount of fossil and DNA evidence that points to Africa as the origin of modern humans.  There are lots of things that argue man may have evolved in Eurasia as well.  There was a shared habitat in Asia and Africa a couple million years ago.  It is nicknamed Savanastan.  Animals migrated back and forth.  Some animals evolved in Africa and moved to Asia.  Some animals evolved in Asia and moved to Africa.  Cheetahs apparently evolved in North America and moved all the way back to Africa.  With all this migrating back and forth, I too get kind of irritated at the suggestion that there was a one way road out of Africa for our ancestors.  Clearly the evidence is too sparse to make definitive conclusions.  It is very possible, in my opinion for there to be a very large contribution in our ancestry from Asia or other places besides Africa.  It has almost become a religion to some and to even question it will get you castigated.  I have recently read, the New Human, about the Hobbit, H. floresiensis discovery.  Michael Morewood talked about the necessity, irritating to him, to have to pay homage to the Out of Africa crowd or risk ridicule (heavily paraphrased).