Hybrid Hypothesis Dead, Done, Stick A Fork In It....

[guyzonthropus]

Would it be possible that the hybridization involved not Neanderthals, but rather an intermediate form of homogenous or even some extant population of H. erectus or some other such species we've yet to find fossil evidence of?

Maybe a root species could still reproduce with the forms that arose from it should their populations once separated reconnect and interact through some means such as bottlenecks, land bridges, environmental shifts or even simple migrations.

Perhaps we split from BF at a bottlenecked point where our lineage had only the 46 within the populations that survived the event and that which became BF could have been populations located someplace quite distant from us, facing a different set of environmental selective factors, thereby driving our disparate paths of development to the distinctive forms we have today, yet arising from the same species. The might in part explain the "human contamination" issues.

I don't know enough about toxicology, but is it possible that some plant toxins ingested by a localized population might, over time/generations have an effect on our chromosomal makeup? That it could target specific portions of our DNA at any of any number of stages of either replication or development? Then these people prove to be a post bottleneck founder stock? Its a lot of ifs, but many things are...

Geographical isolation is usually a factor in speciation, so another possibility may be that there were isolated groups advancing along their distinct processes of speciation who then encountered one or more of the other still related outlier groups who while diverging were still able to hybridize amongst each other resulting in trait-swapping as it were producing evermore variants to be tested for viability. Just a thought.

I wonder to what degree cultural differences played in these circumstances? Surely different environments would have fostered different interpretations as to why things are/happen as they do, just as diverging social contexts would give rise to varied social constructs "no daughter of mine is 'going to the river' with one of those hairy people!" But then not only did it turn out the hairy folks were a lot stronger than the pinks, they had also discovered just how good a bedwarmer those cute little she-pinks make....So much for custom!

[Yuchi1]

^^^ Good (open minded) points in post #226, we have only a glimpse of all the possible cause-and-effect events that may have occurred over the eons.

Edited April 23, 2016 by Yuchi1

[hiflier]

Going at this from a different angle do the 46 Human chromosomes match up with 46 of the 48? If so then what was lost, or gained, as a result of the fusing? i.e., which physical traits were altered? Brain size or function? Musculature? Hip/knee/foot morphology? Hair?

Also with the discovery of the Zika virus being a strong candidate for microencephaly and Africa being it's apparent source could the chromosomal mutation be the result of a viral nature? If the population of individuals with 46 chromosomes was larger then as guyzonthropus mentioned a bottleneck could have occurred during maybe an ancient outbreak of Ebola? I know science is looking hard for such answers because science really DOES want to know our story.

Had the Library at Alexandria not burned we would have had three volumes of the History of the World which supposedly covered a little over 400,000 years of oral (as far back as there was language) and written history. What a tremendous loss! Science is looking hard for those books as well thinking there maybe copies buried somewhere. I have my own musings on such things.

[Guest Cryptic Megafauna]

Wait until radio logical pollution peaks in a hundred years or so.

Then we will have all kinds of new genes and gene counts.

I wonder what a Bigfoot mutant would look like?

[SWWASAS]

Radio logical pollution?     You talking about DNA damage due to EM radiation?    Some very intelligent people (Steven Hawking for one) claim that we are broadcasting to the universe how primitive we are by emitting radio waves into space and some advanced intelligence could show up to pillage the planet and enslave or eat us.    An advanced intelligence would not likely betray their existence to unknown star travelers.  

Edited April 23, 2016 by SWWASASQUATCHPROJECT

[norseman]

https://en.m.wikipedia.org/wiki/Chromosome_2_(human)

All members of Hominidae except humans, Neanderthals, and Denisovans have 24 pairs of chromosomes.[4] Humans have only 23 pairs of chromosomes. Human chromosome 2 is a result of an end-to-end fusion of two ancestral chromosomes.[5][6]

The evidence for this includes:

The correspondence of chromosome 2 to two ape chromosomes. The closest human relative, the chimpanzee, has near-identical DNA sequences to human chromosome 2, but they are found in two separate chromosomes. The same is true of the more distant gorilla and orangutan.[7][8]

The presence of a vestigial centromere. Normally a chromosome has just one centromere, but in chromosome 2 there are remnants of a second centromere.[9]

The presence of vestigial telomeres. These are normally found only at the ends of a chromosome, but in chromosome 2 there are additional telomere sequences in the middle.[10]

Chromosome 2 is consistent with the common ancestry of humans and other apes. According to researcher J. W. IJdo, "We conclude that the locus cloned in cosmids c8.1 and c29B is the relic of an ancient telomere-telomere fusion and marks the point at which two ancestral ape chromosomes fused to give rise to human chromosome 2." [10]

[bipedalist]

As I said, nothing "yhuge" about it. Sometimes genetics and reassortment is strange.

[norseman]

Explain?

[hiflier]

https://en.m.wikipedia.org/wiki/Chromosome_2_(human)

All members of Hominidae except humans, Neanderthals, and Denisovans have 24 pairs of chromosomes.[4] Humans have only 23 pairs of chromosomes. Human chromosome 2 is a result of an end-to-end fusion of two ancestral chromosomes.[5][6]

The evidence for this includes:

The correspondence of chromosome 2 to two ape chromosomes. The closest human relative, the chimpanzee, has near-identical DNA sequences to human chromosome 2, but they are found in two separate chromosomes. The same is true of the more distant gorilla and orangutan.[7][8]

The presence of a vestigial centromere. Normally a chromosome has just one centromere, but in chromosome 2 there are remnants of a second centromere.[9]

The presence of vestigial telomeres. These are normally found only at the ends of a chromosome, but in chromosome 2 there are additional telomere sequences in the middle.[10]

Chromosome 2 is consistent with the common ancestry of humans and other apes. According to researcher J. W. IJdo, "We conclude that the locus cloned in cosmids c8.1 and c29B is the relic of an ancient telomere-telomere fusion and marks the point at which two ancestral ape chromosomes fused to give rise to human chromosome 2." [10]

That's good info but it doesn't address the following questions:

 

....then what was lost, or gained, as a result of the fusing? i.e., which physical traits were altered? Brain size or function? Musculature? Hip/knee/foot morphology? Hair?

And if genetically modifying a Human reproductive cell from a male and female by separating the telemere-fused chromosome what Hominidae would one then get? Pongo? Gorilla? Pan? I don't doubt that it's been tried either.

[bipedalist]

Explain?

 

I made a reference in a post back several ago that mentioned it is not so much the number of chromosomes that is the enigma as that info was intact in regard to many files when recombined or fused.  Of course, something switched on in the form of epigenetics and/or turning genes on/off through regulation as well.  A mutation here or there and then natural selection takes over from there. I can guarantee you that one of those mutations was increased neural folding of cortex to make more room for convolutions (gyri and sulci) (along with your FOXP2 language gene).

 

Maybe a bottleneck, maybe not but hard to imagine not.  http://www.ncbi.nlm.nih.gov/pubmed/12733395 Of course, there are those that disagree with the role of mitochondrial DNA, Ancestral Eve and just what a Homo sapienis is too.  

Edited April 23, 2016 by bipedalist

[hiflier]

Just for general knowledge. Separating the central telomere in Human chromosome 2, if it could be done, would change nothing. Joining the telomeres of chromosome 2 in a Chimpanzee likewise will result in nothing. In other words a change in either will not turn a chimp into a Human nor visa versa. The reason is neither evolved from the other. The change in chromosome 2 occurred at the split from the common ancestor and gorillas split from that ancestor even before Human/chimp speciation.

Thought you'd like to know.

Edited April 24, 2016 by hiflier

[FarArcher]

Just for general knowledge. Separating the central telomere in Human chromosome 2, if it could be done, would change nothing. Joining the telomeres of chromosome 2 in a Chimpanzee likewise will result in nothing. In other words a change in either will not turn a chimp into a Human nor visa versa. The reason is neither evolved from the other. The change in chromosome 2 occurred at the split from the common ancestor and gorillas split from that ancestor even before Human/chimp speciation.

Thought you'd like to know.

 

Coincidentally, every morning, I add to my coffee Astragaloside IV (AG-IV) and Cycloastragenol (CGA) to activate telomerase to lengthen my own telomeres.

 

I may mutate myself.

 

Hope you're right, hifflier.

[hiflier]

Who are you really and what have you done with FarArcher

[FarArcher]

Who are you really and what have you done with FarArcher

 

It's not big deal.

 

I include some astragalus root powder in my coffee.  Read up on it.  You might want to use it yourself.

 

The commercial version they charge an arm and a leg for is termed TA-65.  And that's just a derivative of the CGA.

[norseman]

https://en.m.wikipedia.org/wiki/Chromosome_2_(human)All members of Hominidae except humans, Neanderthals, and Denisovans have 24 pairs of chromosomes.[4] Humans have only 23 pairs of chromosomes. Human chromosome 2 is a result of an end-to-end fusion of two ancestral chromosomes.[5][6]The evidence for this includes:The correspondence of chromosome 2 to two ape chromosomes. The closest human relative, the chimpanzee, has near-identical DNA sequences to human chromosome 2, but they are found in two separate chromosomes. The same is true of the more distant gorilla and orangutan.[7][8]The presence of a vestigial centromere. Normally a chromosome has just one centromere, but in chromosome 2 there are remnants of a second centromere.[9]The presence of vestigial telomeres. These are normally found only at the ends of a chromosome, but in chromosome 2 there are additional telomere sequences in the middle.[10]Chromosome 2 is consistent with the common ancestry of humans and other apes. According to researcher J. W. IJdo, "We conclude that the locus cloned in cosmids c8.1 and c29B is the relic of an ancient telomere-telomere fusion and marks the point at which two ancestral ape chromosomes fused to give rise to human chromosome 2." [10]

That's good info but it doesn't address the following questions: 

....then what was lost, or gained, as a result of the fusing? i.e., which physical traits were altered? Brain size or function? Musculature? Hip/knee/foot morphology? Hair?

And if genetically modifying a Human reproductive cell from a male and female by separating the telemere-fused chromosome what Hominidae would one then get? Pongo? Gorilla? Pan? I don't doubt that it's been tried either.

Your going to have to dig on this chromosome 2. This might help.

https://en.m.wikipedia.org/wiki/Chimpanzee_genome_project

It would seem as Bipedalist points out (thanks) that the fusion seems to have something to do with speech and brain development.

Neanderthals and Denisovians also had this chromosome 2.