The case for Homo Erectus

[hiflier]

^^^ The only way to estimate such dates would be to know what the DNA mutation rates are. Science seems pretty certain of what those rates are so is probably fairly close in its assessments regarding evolutionary dating. But, again, science is a progressive learning process so the future more than likely will result in even more improved accuracy. Seems to be the (basically ego-driven) direction its going in right now anyway  

Edited November 6, 2021 by hiflier

[MIB]

On 11/6/2021 at 3:12 PM, hiflier said:

The only way to estimate such dates would be to know what the DNA mutation rates are.

 

Right.   Then the second question should be "what can cause discontinuities in the normal mutation rates."    In other words, say mutations happen pretty steadily at 1 per "X" years.   Are there situations / events that can drive the rate temporarily to even 25-50 in "X" years before they return to the background / normal rate of 1 per "X"?    How would we know with any certainty?

[hiflier]

Evolutionary genetists could probably get you closer to some answers. One would think they would be some of the first people who to want to know so there are probably articles on the interwebs that address those issues.

Edited November 8, 2021 by hiflier

[gigantor]

3 hours ago, MIB said:

Are there situations / events that can drive the rate temporarily to even 25-50 in "X" years before they return to the background

 

Or situations where no mutations occur for 'X' number of years.

 

[MIB]

1 hour ago, hiflier said:

Evolutionary genetists could probably get you closer to some answers. One would think they would be some of the first people who to want to know so there are probably articles on the interwebs that address those issues.

 

No argument.  I'm just not sure where you find evidence for that which wouldn't be circular .. relying on itself for validation.   You'd need some other biological timeline .. some sort of "control" .. but it would still would be subject to the same conditions thus not a reliable ... crossreference.    Just guessing though.  

[hiflier]

Probably shooting blanks here but environmental forcing could be a factor over time such as climatic or other upheavals that change landscapes from verdant to arid. Or volcanic activity that affects food supply causing malnutrition and reproductive bottlenecks. Obviously this would suggest that environments were not constant which complicates evolutionary genetic mutations so more than likely needs a more multidisciplinary approach and study. In a perfect world where nothing changes it would be easier to look at DNA mutations involving additions or deletions as a smoother more linear dynamic. Factor in interbreeding on top of all the other variables and the picture becomes even more complex.

 

Be that as it may, when it comes to the subject of the Sasquatch, there isn't a whole lot to go on outside of reasonable evolutionary speculation for launching an attempt to place it somewhere in the primate line. It's a perfectly normal exercise but relies most heavily on peripheral knowledge being brought to bear on a central fairly unknown creature, zoologically and genetically. And yet there still is, IMO, good possibilities for estimating its genetic distance between Chimps and us. For instance, we know the mutational base pair differences between us and chimps as well as the base pair differences between us and Denisovan as well as Neanderthal. Having its advanced primate body does give us some advantages for where to, more or less, plug the Sasquatch into the evolutionary line. For me it helps to do that, as a trial run anyway, when setting up a hypothetical ballpark base-pair differential that could be investigated should any trace evidence yield good quality DNA. That may be the only way forward since the GenBank lacks Sasquatch genetic sequences. It has taken time and effort to develop this opinion but I think it is about as sound in its reasoning as it gets....uh....IMHO  

[MIB]

2 hours ago, hiflier said:

Probably shooting blanks here but

 

... but that's exactly the sort of thing I was thinking.         The side point is it'd be hard to measure "linearly" because whatever yardstick you'd try to use for comparison might well be impacted by the same factors.   If that happens, there could be bursts of change and periods of sameness and there'd be no way to tell them apart.    .. eh, give or take.

[hiflier]

What you say has merit for sure and I get what you mean. I would like to take this a step further if I may. There are 202 mtDNA base pair differences between Neanderthal and modern Humans. That means that out of 16,569 total mtDNA base pairs, 202 are nucleotides (base pairs) that are not shared. Since science also looks at strata and other things (like argon, krypton, and uranium isotope half lives) when doing dating they have found that in doing such other kinds of dating that they have been able to correlate DNA base pair insertion, substitution, and deletion rates with that other temporal data. When those isotope's half lives are measured in bones or teeth it gets even better. In effect science has been able to determine that in the general sense, DNA mutations are essentially a genetic time code. With Chimpanzees there is over 1,600 base pair differences. Time between us and Chimps? about 6-7 million years.

 

Denisovans? about 40-50,000 years with a difference of over 600 base pairs. Denisovan 3, however, only has a difference of between 3-400 base pairs which places it closer in time than the 50,000 year old Denisovans, but still not as close as Neanderthal's 30,000 years.  Geographic separation can  also mean how long a species had been isolated from the Homo which can alter the genetic mutation timeline. So, to me, that is saying that there IS a mutation rate that science has determined in order to approximate at least to a few thousand years of accuracy in the Homo order of things. Is that good enough to say that mtDNA mutations can be used to determine a particular Homo fossil's age? I would say yes. Is it a perfect ruler. No, not yet. But it looks pretty close. Don't forget, I'm no expert in this stuff

Edited November 9, 2021 by hiflier

[hiflier]

Don't know if this helps beyond showing that science is on it. Just don't ask me to interpret it into the real world   https://www.nature.com/articles/s41598-021-84583-1

 

Edited November 9, 2021 by hiflier

[MIB]

11 hours ago, hiflier said:

Is it a perfect ruler. No, not yet. But it looks pretty close. Don't forget, I'm no expert in this stuff

 

It is independent verification .. just about anything of that sort beats using "x" to validate "x".    Thanks for sharing.

[hiflier]

Agreed!  And good point, we've seen a lot of unverified "x" that somehow gets turned into fact and then gets erroneously used to verify "y." Digging into factual science as support for a hypothesis is a valid approach. Even if one paints a picture yet to be true, it's still on more solid ground than turning conjecture into some kind of reliable reference to push speculation. Appreciate your well thought out input on this.

Edited November 9, 2021 by hiflier