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What is the cause of existence?

 
 
Olivier5
 
  1  
Reply Mon 1 Jul, 2013 02:05 pm
@farmerman,
Quote:
European DNA has 1 to 2% Nenaderthl. Over the period of 1000 or more generations after Neanderthals died, THATS HUGE

Generations shouldn't make any difference if those specific neanderthal alleles are neutral re. survival.

If they provide an advantage in terms of survival (or breeding), population genetics theory implies that their % will increase over time in the general population. If they bring a disadvantage, their share will decrease over many generations.

So it could be, for instance, that the original (say, circa 30,000 years ago) percentage of neanderthal alleles in sapiens was say 0.5%, and it rose over generations to the modern level of 1 to 2% because those alleles were on average beneficial.
farmerman
 
  1  
Reply Mon 1 Jul, 2013 02:09 pm
@Olivier5,
alleles are the total summation of genes in a chromosome. They are gene pairs. SO, yes they are the same thing. If you read Fairbanks book youll see how the statistics in comparing the % of genic compliments work.
Besides, the decline of Neanderthal Genes in our genome would naturally occur AFTER an initial statistical maximum was achieved only while NEanderthals lived. Once they died off, their gene % would also begin to decline as the compliment they brought to the mix were no longer fixed by routine coupling.

Genes can be lethal, beneficial or neutral. In each case the % will not be changed because they fit a specific SITE .HOX/NANOG/ and Hedgehog genes each code for a specific site function. They don't Take over the genome and increase in concentration. New genes are added through time and sex linkage will dilute the percentage that any one of these genes occupies.

That's the beauty of evolutions "bookkeeping" when our common ancestors no longer are around, we can look at the gene compliment between us an say, chimpanzees and actually calculate approximately when we split off. The % of , say, human and chimpanzee NANOG genes (and their attendant ALU segments ) remained constant but with the appearance of new genes NANOG a from Chimps actually decreases in occurrence on the genome
BillW
 
  1  
Reply Mon 1 Jul, 2013 02:10 pm
@farmerman,
While interbreeding is viewed as the most parsimonious interpretation of the genetic discoveries, the authors point out they cannot conclusively rule out an alternative scenario, in which the source population of non-African modern humans was already more closely related to Neanderthals than other Africans were, due to ancient genetic divisions within Africa.

Among the genes shown to differ between present-day humans and Neanderthals were RPTN, SPAG17, CAN15, TTF1 and PCD16.
Olivier5
 
  1  
Reply Mon 1 Jul, 2013 02:13 pm
@farmerman,
Quote:
alleles are the total summation of genes in a chromosome. They are gene pairs.

Nope. Alleles are forms taken by a gene. You and I have 100% the same genes (provided you're a man) but we have different alleles.

Quote:
Besides, the decline of Neanderthal Genes in our genome would naturally occur AFTER an initial statistical maximum was achieved only while NEanderthals lived. Once they died off, their gene % would also begin to decline as the compliment they brought to the mix were no longer fixed by routine coupling.

No no no... This is all wrong. The only reason a particular allele will go up or down in a population is if it brings a significant advantage or disadvantage to its bearers. Otherwise its proportion re. the whole population remains stable.
farmerman
 
  1  
Reply Mon 1 Jul, 2013 02:22 pm
@BillW,
yep. The initial "out of Africa was H heidelbergensis(maybe)". That's wht Reich and Paabo are all about now, with a somewhat revised "out of Africa" hypothesis
0 Replies
 
farmerman
 
  1  
Reply Mon 1 Jul, 2013 02:30 pm
@Olivier5,
Quote:

No no no... This is all wrong. The only reason a particular allele will go up or down in a population is if it brings a significant advantage or
If a site is HOX, it isn't going to increase in percentage of the total compliment. As new genes re added and new forms evolve AFTER a population dies out, its genetic effect will decrease (even though a series of genes remains)

PS, yes you are correct re alleles We usually refer to them in pairs where diff alleles of the same gene produce different effect on the phenotype (if I recall my Mayr ) Sorry if I confused anyone
0 Replies
 
farmerman
 
  1  
Reply Mon 1 Jul, 2013 02:32 pm
@Olivier5,
Quote:

Generations shouldn't make any difference if those specific neanderthal alleles are neutral re. survival.
Why is my Creationist buzzer going off?
0 Replies
 
farmerman
 
  1  
Reply Mon 1 Jul, 2013 02:32 pm
@Olivier5,
Quote:

Generations shouldn't make any difference if those specific neanderthal alleles are neutral re. survival.
Why is my Creationist buzzer going off?
Olivier5
 
  1  
Reply Mon 1 Jul, 2013 02:36 pm
@farmerman,
Must be broken...

The Hardy–Weinberg principle (also known as the Hardy–Weinberg equilibrium, model, theorem, or law) states that allele and genotype frequencies in a population will remain constant from generation to generation in the absence of other evolutionary influences.
http://en.wikipedia.org/wiki/Hardy%E2%80%93Weinberg_principle
farmerman
 
  1  
Reply Mon 1 Jul, 2013 03:35 pm
@Olivier5,
You've mentioned Hardy Weinberg and missed a key point.The genic contents of a population will be the same from generation to generation if it were not for the addition of new genes , or the loss of existing genes, you know, the stuff that's responsible for evolution.
We map short-tandem-repeat alleles (STR's) and see these as defining population biogeography and these may be only a few p[ercentages of occurrence in the population . Also They usually occur in non coding DNA where they do nothing but to become a "map" of where a population originated.
farmerman
 
  1  
Reply Mon 1 Jul, 2013 03:40 pm
@BillW,
That's called "ubstructuring" and Paabo argues with Greene (the originator of the critiques on Paabo and Reich) that such substructuring is less parsimonious than interbreeding

However, the percentages keep varying. I saw a newer study that said 4% of North African and Eurasian genomes contain Neanderthal genes.
0 Replies
 
farmerman
 
  1  
Reply Mon 1 Jul, 2013 03:40 pm
@BillW,
That's called "ubstructuring" and Paabo argues with Greene (the originator of the critiques on Paabo and Reich) that such substructuring is less parsimonious than interbreeding

However, the percentages keep varying. I saw a newer study that said 4% of North African and Eurasian genomes contain Neanderthal genes.
BillW
 
  1  
Reply Mon 1 Jul, 2013 04:01 pm
@farmerman,
I know very little about the subject of dna, but I do know that even 0.005 % can be material, if it is relevant. One other thing, it depends on if it is turned on. And, lastly (I'm really stretching it here) these things can change depending on other factors - brown hair, female, etc.

I have seen people (especially in jr high school) who look very much like neanderthals, and guess what - they were in special ed. No way I didn't believe they weren't extinct. I know it is claimed such, but if dna are being carried forward, there isn't a total extinction.
0 Replies
 
Olivier5
 
  1  
Reply Mon 1 Jul, 2013 04:35 pm
@farmerman,
Quote:
The genic contents of a population will be the same from generation to generation if it were not for the addition of new genes , or the loss of existing genes, you know, the stuff that's responsible for evolution.

Whatever you mean by that, since 30,000 years not much evolution occurred. If you are arguing that the proportion of genetic material from neanderthal in a sapiens population has decreased over time, you gona have to come up with a reason, a selection pressure or another. E.g. red-haired were discriminated against - these sorts of things. Genetic material tends to get reproduced, it doesn't disappear for no reason.
snj
 
  1  
Reply Wed 3 Jul, 2013 09:21 am
@Windevoid,
Everything has a cause to exist for a limited period of time.For example,we know that dinosaurs existed millions of years ago.To adapt to the environment,a new species of animals was evolved called mammals.When the dinosaurs died out,eventually the species which was trying to defend itself from the dinosaurs,mammals;became the new superior species.
Fil Albuquerque
 
  1  
Reply Wed 3 Jul, 2013 09:30 am
@Windevoid,
"Causation" describes correlations within space n time...it is a useful concept.
0 Replies
 
Setanta
 
  1  
Reply Wed 3 Jul, 2013 12:21 pm
I read Olive Tree's post when it becomes evident (usually from the responses of others) that he's posting bullshit. So, for example, 30,000 years is well over 2000 generations (females become fecund at about 13 years of age, but i'm using a more generous estimate--in terms of OT's claim--of 15 years). A great deal can change in 30,000 years. Most students of hominid pre-history place the disappearance of h. neanderthalis at 35,000 years go or earlier.

As for bands of murderous humans running around, i don't think OT has any idea of what population densities were in early hominid history. As an example, all human females are directly descended from Mitochondrial Eve, who lived 190,000 to 200,000 years ago. Obviously, hominids faced extinction on more than one occasion, and hominid populations were very, very small until the agricultural revolution of about 10,000 years ago. Even more striking is Y-chromosomal "Adam" who is thought to have lived anywhere from 540,000 to 230,000 years ago. At least once and very likely more than once in that period, hominids were on the brink of extinction.

The idea that humans were running around slaughtering other hominids is preposterous. Prior to the rise of agriculture, the human population very likely never exceeded 10,000 persons, and they were scattered across the African and Eurasian landmasses. That's the kind of population density that makes Alaska look positively crowded. In fact, in an article in Nature two years ago, two Harvard geneticists estimate that the entire human population of the Eurasian landmass 30,000 years ago may well have been as few as 1000 individuals. (The link is for a USA Today article, and not the article in Nature.)

That puts all of that killer ape horseshit into perspective. It is likely that there was not competition for food resources among hominids of the ice ages. What would quickly become vast forests in Eurasia 15,000 years ago after the retreat of the glaciation were vast, grassy steppes during the ice ages. (As usual, Bill doesn't know what the hell he's talking about--grazing species moved north during the ice ages because of fodder resources which were available where only riparian gallery forests existed and most land was covered in grass and forbs.) Bison and giant bison, elk, megaceros, wooly mammoth, auroch and saiga are just a few of the game species which were available. There were also marmots and giant ground squirrel, as well as a host of medium to small game animals. There were ptarmigan and grouse, and many other edible bird species. Those grasses also included einkorn and emmer (the ancestors modern wheat), as well as rye, oats and barley. Fruits, nuts and berries were plentiful. Significantly, there is good archaeological evidence that h.s.s. traveled to sea or ocean shores to set up salt pans, and that fish, roe and shellfish were a part of their diet. In some of the Isreali sites, sea shells have been recovered which are thought to have been gathered for decorative purposes, as they would not have provided a significant food source. They obviously had some leisure for other than food gathering activities.

But what is significant i have already referred to, and that is the relative bare larder of h.n. as compared to h.s.s. I've already pointed out that Isreali archaeologists have found sites where h.n. and h.s.s. lived side by side. Israeli excavations of middens have also shown that h.s.s. used far more forage plants, as well as fish, roe and seafood--than did h.n. Neanderthals appear in Europe from 600,000 to 350,000 years ago (depending on whose story you accept). The great glaciations begin after that--the Riss glaciation lasting from about 180,000 to 130,000 ybp, and the Würm glaciation (the most recent) from about 80,000 to 15,000 ybp. It is entirely possible that h.n., a theretofore successful species, began to decline with the ice ages, and to slowly, very slowly reach a point where deaths outran live births.

You don't need killer apes à la Konrad Lorenz to explain why h.s.s. managed to hang on and h.n. didn't. The proposition that humans exterminated "the competition" is an absurdity for a variety of reason, not the least of which is that there simply was no competition for food resources when populations were so small that they represented a fraction of a percent of the humber of humans who could have comfortably survived on the available resources.
farmerman
 
  1  
Reply Wed 3 Jul, 2013 12:24 pm
@Olivier5,
Quote:

Whatever you mean by that, since 30,000 years not much evolution occurred.
Youre the one who first posted the HArdy Weinberg expansion . Its a fact that we can identify the time that Neanderthals went away and,(whatever their original interbreeding amount was ), when they went extinct, their genes were thus removed from the genome of Hs.
In a 30K period weve lost H s Idaltu, H n, Hd, and the "hobbits".

Extinction is a big part of the evolution train.
farmerman
 
  1  
Reply Wed 3 Jul, 2013 12:26 pm
@snj,
Quote:


Everything has a cause to exist for a limited period of time.For example,we know that dinosaurs existed millions of years ago.


Dave Raup, a paleontologist statistician had a great line. He said that

1. Dinosaurs were a bad idea from the get-go
and

2. Theyd gone on for quite long enough
0 Replies
 
farmerman
 
  1  
Reply Wed 3 Jul, 2013 12:47 pm
@Setanta,
That's also a very important point in the storyline based upon the existence of pseudogenes in a population. These non functional copies may exist in unrelated familial populations of a single species and record lots of evolutionary pressures. Thus they were able to see , from samples of recent fossil bone and teeth that, with the eruption of Toba about 75K years ago, the entire human population was depleted to less than 1000 individuals.

0 Replies
 
 

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