Theistic evolutionists: was Adam a specific person?

[sfs]

So what? For the next 2000 years the Jews believed and still believe Jesus was not the Messiah, the son of god. Believing something for 2000 years (even with a lot of people believing it) doesn't make something true

It might be worth noting that after the beginning of Genesis, Adam is mentioned exactly once in the Old Testament. He was not an important figure in Jewish thought of the time.

 

[sfs]

Suppose we have 10 mutations took place in 10 individuals who live in a community: Mutation A, Mutation B .... etc.
With the increase of descendants on each individual, let's assume 5 mutations gained increase on its frequency: Mutation A, B, C, D, and E.

First question: It seems you suggested that the effect of these five mutations could be "combined" to manifest an overall change of characteristics of the population. If this is correct, then how is it done? For example, if one inherited mutation A mated with another one inherited mutation B, would their offsprings start to show the effect of mutation A or mutation B, AND/or mutation (A+B), which is a NEW character in the population? Could we call the mutation(A+B) a new mutation and labelled it as Mutation F, and may start to gain increase on its frequency?

Let's assume each of these mutations is on a different chromosome. Then they can combine independently. If I have a copy of A and my wife has a copy of B, then some of our kids will have A, some B, some A+B and some neither (assuming we have a whole lot of kids). The ones who have A+B can pass on either or both or neither to their kids; the frequency of A and B in the population will change independently over the generations. If they both increase, eventually you'll have some people with two copies of A or two of B, or A+2B, etc.

What the effect of A+B is on the person depends on the specific biology of those mutations. If A and B each have an effect (call it a and b), then most commonly they'll have trait a+b (an additive trait). So if A makes you a little taller and B makes you a little paler, A+B will make you a little taller and paler. Or they could both make you paler, and A+B will make you even paler. Sometimes, though, A+B will have exactly the same effect as either A or B by itself; adding the second one won't change anything. Sometimes they'll cancel. Sometimes they'll produce a third, completely different trait. But mostly they just add.

 

[juvenissun]

Let's assume each of these mutations is on a different chromosome. Then they can combine independently. If I have a copy of A and my wife has a copy of B, then some of our kids will have A, some B, some A+B and some neither (assuming we have a whole lot of kids). The ones who have A+B can pass on either or both or neither to their kids; the frequency of A and B in the population will change independently over the generations. If they both increase, eventually you'll have some people with two copies of A or two of B, or A+2B, etc.

What the effect of A+B is on the person depends on the specific biology of those mutations. If A and B each have an effect (call it a and b), then most commonly they'll have trait a+b (an additive trait). So if A makes you a little taller and B makes you a little paler, A+B will make you a little taller and paler. Or they could both make you paler, and A+B will make you even paler. Sometimes, though, A+B will have exactly the same effect as either A or B by itself; adding the second one won't change anything. Sometimes they'll cancel. Sometimes they'll produce a third, completely different trait. But mostly they just add.

This is amazingly complicate.

So, if we have an original population of 5000, and they all interbreed so a lot of mutations took places generation after generation. Assume we do see an overall change of characters of the expanding population over time, what is the main factor that "guided" the result of all these mutations? Could it be summarized as THE ENVIRONMENT in which this group of individuals lived in?

 

[sfs]

This is amazingly complicate.

So, if we have an original population of 5000, and they all interbreed so a lot of mutations took places generation after generation. Assume we do see an overall change of characters of the expanding population over time, what is the main factor that "guided" the result of all these mutations? Could it be summarized as THE ENVIRONMENT in which this group of individuals lived in?

Biology is not simple. I haven't even mentioned recessive mutations, or what happens when the mutations are on the same chromosome.

Some of the overall changes in the population will be random: traits that don't affect survival or reproduction can vary freely and they'll just drift around. Most of the changes to interesting traits can indeed be ascribed to the effect of the environment, which includes a whole lot of stuff: available food, competitors, parasites, pathogens, temperature, predators.

 

[juvenissun]

Biology is not simple. I haven't even mentioned recessive mutations, or what happens when the mutations are on the same chromosome.

Some of the overall changes in the population will be random: traits that don't affect survival or reproduction can vary freely and they'll just drift around. Most of the changes to interesting traits can indeed be ascribed to the effect of the environment, which includes a whole lot of stuff: available food, competitors, parasites, pathogens, temperature, predators.

If so, how likely is that humans were evolved independently from more than one locality? For example, a species of human evolved in Asia and another species of human evolved in the Baltic? I want to emphasize that in both cases, they WERE true human species. [someone may start to ask: what is human? But, please don't, otherwise, the discussion can't be continued.]

To me, the chance should be near zero.

 

[sfs]

If so, how likely is that humans were evolved independently from more than one locality? For example, a species of human evolved in Asia and another species of human evolved in the Baltic? I want to emphasize that in both cases, they WERE true human species. [someone may start to ask: what is human? But, please don't, otherwise, the discussion can't be continued.]

To me, the chance should be near zero.

If I understand you correctly, I agree. There's next to zero chance that two independent populations of proto-humans would both evolve into modern humans. In reality, humans modern humans evolved in Africa and spread as one species from there. There's also been some flow of genes (interbreeding) between nearly all human populations, which tends to keep them all more or less synchronized. In other words, they will all have pretty much the same set of common mutations.

 

[juvenissun]

If I understand you correctly, I agree. There's next to zero chance that two independent populations of proto-humans would both evolve into modern humans. In reality, humans modern humans evolved in Africa and spread as one species from there. There's also been some flow of genes (interbreeding) between nearly all human populations, which tends to keep them all more or less synchronized. In other words, they will all have pretty much the same set of common mutations.

OK. I think we can come back to the OP more closely.

If human evolved from one locality (somewhere in Africa), then how do we estimate the size of population of that evolving group?

To me, it could be any size ranged from two (Adam and Eve) to a realistic number of individuals lived together in that locality, for example, 100. Is this an idea acceptable to you? If not, how do you eliminate the possibility of being only two?

 

[sfs]

OK. I think we can come back to the OP more closely.

If human evolved from one locality (somewhere in Africa), then how do we estimate the size of population of that evolving group?

To me, it could be any size ranged from two (Adam and Eve) to a realistic number of individuals lived together in that locality, for example, 100. Is this an idea acceptable to you? If not, how do you eliminate the possibility of being only two?

I eliminate the possibility for the same reason that I've stated repeatedly: we find lots and lots of low frequency genetic variants in the human population, and that distribution of variants could not come from a rapidly expanding, tiny population in the recent past.

 

[Rock in a Pond]

I like tigers

 

[PsychoSarah]

m

I don't care how people use log scale to shrink the apparent value of number, the fact is it is a big number, and it means the chance is not only "less likely", but is very very unlikely. The emphasis must be given.

If so, why do we have a number of cases of white tiger, but zero case of red tiger green tiger or black tiger? I would think a green tiger is even more environmentally advantageous.

Now, back to the old question: Why should "Adam" represent a large number of humans, rather than a single human? I don't see a reason for that from the genetic (mutation) point of view.

Actually, all white Bengal tigers originate from just 1, which was bred and then inbred with its offspring to make more tigers with that trait. I could even tell you what year that tiger was found. It likely only survived because humans caught it and raised it in captivity. In most cases, albino animals and animals with coloring that contrasts with the surroundings don't do so well unless they are poisonous, which tigers are not.

A green tiger probably would be at some advantage... if they were surrounded by greenery. If you check out their actual habitat, they do blend in pretty well, actually. Especially considering the fact that orange appears brown to many prey animals, hence why hunters can get away with bright orange portions on their outfits; deer don't see the color as standing out. Animals that would see it most commonly would be birds, which are too small for most tigers to give a crap about, and other predators, which tend to be more trouble than they are worth to hunt. In any case, if a mutation doesn't happen, it doesn't happen. Evolution is not perfect, hence why extinction without leaving behind a daughter species is so common.

 

[juvenissun]

I eliminate the possibility for the same reason that I've stated repeatedly: we find lots and lots of low frequency genetic variants in the human population, and that distribution of variants could not come from a rapidly expanding, tiny population in the recent past.

Very good. Could I ask how long would be a proper time period for the known existence of those low frequency variants? Is 3 million years long enough for that?

 

[juvenissun]

Actually, all white Bengal tigers originate from just 1, which was bred and then inbred with its offspring to make more tigers with that trait. I could even tell you what year that tiger was found. It likely only survived because humans caught it and raised it in captivity. In most cases, albino animals and animals with coloring that contrasts with the surroundings don't do so well unless they are poisonous, which tigers are not.

A green tiger probably would be at some advantage... if they were surrounded by greenery. If you check out their actual habitat, they do blend in pretty well, actually. Especially considering the fact that orange appears brown to many prey animals, hence why hunters can get away with bright orange portions on their outfits; deer don't see the color as standing out. Animals that would see it most commonly would be birds, which are too small for most tigers to give a crap about, and other predators, which tend to be more trouble than they are worth to hunt. In any case, if a mutation doesn't happen, it doesn't happen. Evolution is not perfect, hence why extinction without leaving behind a daughter species is so common.

Many zoos has white tiger. Are you suggesting that they all originated from the place where the first one was found?
If so, I don't think the breeding of white tiger offsprings from that original one is genetically controlled. Somehow that white tiger was just able to give birth to more white tigers without human interfere.
Is the number of white tiger increasing continuously?

 

[PsychoSarah]

Many zoos has white tiger. Are you suggesting that they all originated from the place where the first one was found?
If so, I don't think the breeding of white tiger offsprings from that original one is genetically controlled. Somehow that white tiger was just able to give birth to more white tigers without human interfere.
Is the number of white tiger increasing continuously?

Yup, every white Bengal tiger is white because of a trait other than albinism, and they can all trace their roots back to 1 male tiger that was bred and then inbred with its daughters. It is a recessive trait, so 1/2 of that 3rd generation shared the trait, and every white Bengal tiger that breeds with another white Bengal tiger will have the trait. This variety of tiger is more prone to health problems thanks to all the inbreeding, so intelligent breeders allow for some generations to breed with regular Bengal tigers to prevent infertility and whatnot, but generations of inbreeding have still taken their toll. Since that original white tiger was found, no other white Bengal tigers have ever been found in the wild that weren't zoo escapees.

To summarize the genetics, here is how it works. Recessive trait of being white will be represented by a lowercase "w", and the dominant trait of being orange will be represented by a capital O. These are alleles, representations of variation of genes. Alleles exist within our bodies in pairs, and for this trait and these alleles, the possible combinations are ww, Ow, and OO. Only ww tigers will be white.

First breeding: ww male with OO female
Offspring: all Ow males and females, none are white, but they all carry the allele.
Second breeding: ww male with Ow daughter
Offspring: Ow 50%, and ww 50%, there are now multiple white tigers.
Third breeding: ww male with ww female
Offspring: all ww, every tiger born of this pairing is white.

Now if they just kept inbreeding ww tigers from that point, they would have all become infertile and died out, but since they were so popular, people wanted 1 and did similar breeding techniques to get more from the small number that they started out with, since going through all these steps actually gives you more tigers with the trait faster than just inbreeding ww tigers starting at the 3rd breeding, and is the only way to get more if you are a wealthy person back in this time period and purchased just 1.

Increasing continuously? I don't know enough about their current numbers to answer that, but I do know that their popularity in breeding programs is criticized since other tiger species more at risk of extinction often don't get as much breeding attention as the white variant of Bengal tigers, since they are such a crowd pleaser.

 

[Rock in a Pond]

tigers etc

 

[juvenissun]

Yup, every white Bengal tiger is white because of a trait other than albinism, and they can all trace their roots back to 1 male tiger that was bred and then inbred with its daughters. It is a recessive trait, so 1/2 of that 3rd generation shared the trait, and every white Bengal tiger that breeds with another white Bengal tiger will have the trait. This variety of tiger is more prone to health problems thanks to all the inbreeding, so intelligent breeders allow for some generations to breed with regular Bengal tigers to prevent infertility and whatnot, but generations of inbreeding have still taken their toll. Since that original white tiger was found, no other white Bengal tigers have ever been found in the wild that weren't zoo escapees.

To summarize the genetics, here is how it works. Recessive trait of being white will be represented by a lowercase "w", and the dominant trait of being orange will be represented by a capital O. These are alleles, representations of variation of genes. Alleles exist within our bodies in pairs, and for this trait and these alleles, the possible combinations are ww, Ow, and OO. Only ww tigers will be white.

First breeding: ww male with OO female
Offspring: all Ow males and females, none are white, but they all carry the allele.
Second breeding: ww male with Ow daughter
Offspring: Ow 50%, and ww 50%, there are now multiple white tigers.
Third breeding: ww male with ww female
Offspring: all ww, every tiger born of this pairing is white.

Now if they just kept inbreeding ww tigers from that point, they would have all become infertile and died out, but since they were so popular, people wanted 1 and did similar breeding techniques to get more from the small number that they started out with, since going through all these steps actually gives you more tigers with the trait faster than just inbreeding ww tigers starting at the 3rd breeding, and is the only way to get more if you are a wealthy person back in this time period and purchased just 1.

Increasing continuously? I don't know enough about their current numbers to answer that, but I do know that their popularity in breeding programs is criticized since other tiger species more at risk of extinction often don't get as much breeding attention as the white variant of Bengal tigers, since they are such a crowd pleaser.

Thanks. That is enough for me today.

 

[juvenissun]

This thread is about Adam, not tigers.

Well, we might think the original white tiger represents Adam. Then ...

 

[sfs]

Very good. Could I ask how long would be a proper time period for the known existence of those low frequency variants? Is 3 million years long enough for that?

3 million years would be plenty of time. Half a million is too little. Where exactly in between would require study.

 

[PsychoSarah]

Well, we might think the original white tiger represents Adam. Then ...

-_- the white tiger bred with normally colored tigers, and this is 1 trait, not a whole species. Unless you think Adam had a harem of genetically diverse ladies, this example is not analogous.

 

[juvenissun]

3 million years would be plenty of time. Half a million is too little. Where exactly in between would require study.

Given enough time, would it be reasonable to assume that Adam and Eve are real persons?

 

[JacksBratt]

How did you calculate those odds? I'm a differently evolved humanoid from my wife, but we've managed to mate successfully and produce two offspring. We have different collections of mutated genes, but all of the differences are quite small. And the differences between us and our children are small. But if you let small differences every generation accumulate for a hundred thousand generations, then yes, the total difference will be large. Large enough that it would be surprising if they could still successfully mate.

So, your saying that my great great.......x10000 granddaughter could not have children with my neighbors son?

If it is that easy to be non compatible, sexually, with another ancestor, how did two humanoids evolve, separately, from two other humanoid beings and be compatible enough to mate? Your telling me that a generation of human ancestor beings in one area, had offspring that could not mate with their own kind, however, two of these new beings could mate with each other?

Sorry, I'm not taking those odds on any day. Here, in my opinion, evolution has painted itself in a corner. Just the way it did when it stated that two asexual beings separately evolved to having offspring that one was a male and one was a female that were compatible with each other......even if one asexual being evolved by having two of its offspring being one male and one female that were sexually compatible.... boggles the mind.