Hello. A few weeks ago, in my ancient lit class in which we are studying the bible, I brought up the problem of inbreeding with only a few people on the world. The common answer was that the gene pool was very deep, but i growing more shallow. How can this be? Thanks, justin
Each human can carry at most two alleles (different versions) of a gene. If we assume that all of Noah's sons were adopted (so they shared no genes with Noah or his wife), and that the eight people on the Ark were as genetically diverse as possible, that means there were 16 alleles of each gene on the Ark. If Noah's sons were the offspring of him and his wife, and the eight people on the Ark were as genetically diverse as possible, there were 10 alleles of each gene on the Ark.
There are genes for which 59 alleles have been identified in the human population, and there may be genes with more alleles; I don't know. Mutations happen, but the human genome is big, and it takes time (on average) for a gene to mutate. Lots of new alleles don't become fixed in the population because they are disadvantageous (such as killing the carrier). You might expect to see a new allele every 10,000 years to 30,000 years.
There just isn't time in the last hundred thousand years or so for all the genetic diversity of humans to arise from a few individuals. Former Young Earth Creationist Glenn Morton goes into some more detail in Re: Probability and apologetics.
The Biblical model is based on Kinds. This model is also based on the idea that natural selection and mutation is a directional change from High Information, Low Specificity at creation to Lower Information and Higher Specificity currently. The idea is that the original kinds were created before death and mutation were factors (before Adam’s Sin) therefore, the originals had the highest information content. Through natural selection, mutation, and isolation, the specificity we see today emerges.
For example – If Adam is indeed the first human (according to the Bible), then how do we get all the different races, skin colors, etc that we see today. Adam, being the original man, would have to have the DNA for black skin, white skin, and every thing in between. He would also have to have the genetic information for the common African and Asian features, such as large nostrils or ‘slanted’ eyes (that is not meant as a disparagement, but merely an example). Adam would have to have a High level of information in order to pass these traits on to his offspring.
In the same way, there were probably less ‘species’ of dog, for example. Through isolated selection and mutation, information is lost until you arrive at a ‘more specific’ variety.
However, immediately after creation, the people and animals would have been at their very highest information level – and there would be very few mutations. Why is inbreeding dangerous today? Because those in the same immediate family usually have the same genetic defects. Those born from close relations are born with retardation, or are often very sickly. But why? Because their genetic code rely’s on an outside influence to ‘make up for’ the genetic defects in the family line. Chances are, outside the family line someone else will have an un-mutated version of a needed gene. Their genetic structure will contain the necessary information for correction or completion of a necessary gene.
Those immediately born after Adam would have very few genetic mutations, therefore inbreeding would not be dangerous. They would have enough genetic information to overcome any small mutation that might be passed on.
It is important to note that it wasn’t until the days of Moses (about 3000 years after Adam) that God gave laws regarding inbreeding.
Of course this flies directly in the face of modern evolution. Modern evolution says that the directional change goes from simple cell, gains information, and eventually results in complex life forms such as people. However, creationists believe that this is assumptive because no-where in nature can you observe the directional information gaining change required to make Darwinistic evolution possible. So there is contention and controversy between Evolutionists and Creationists.
quote:However, creationists believe that this is assumptive because no-where in nature can you observe the directional information gaining change required to make Darwinistic evolution possible.
Which is only a problem for creationists. Evolutionists don't see this as a problem because the creationist notion of "genetic information" is so muddled as to be useless for scientific purposes. It is possible to define information so as to be applicable to genetics, but then in this case it is not only possible for this type of information to increase, but such increases are observed.
Gup20 - Well, skin color is actually just the ammount of melanin in your skin. I suppose the genes for it simply tell your skin how much melanin to produce. I suppose the thought would be that it started out somewhere in between and mutation corrupted the regulatory cells in some way.
JonF - Pleas expand ... exactly how does this give rise to the different breeds of dogs?
Gup20 - My understanding of the creationist theory is that the original kinds were created with full information, as genes mutated, they became non-functional (or malfunctional) thereby creating a loss of information. For example - a white rabbit in a snowy region. Say there are many rabbits of many colors. The white rabbits have an advantage. Say the genes for other fur colors are damaged or lost - natural selection gives the white rabbits an advantage. Pretty soon there are more white rabbits than any other. Then, the white rabbits only mate with other white rabbits - further increasing the specificity. The animal has lost the genes for other fur colors. The only way to re-introduce other fur color is to breed with a rabbit that is another fur color. Here is an example of increased specificity, and decreased information.
JonF - Why would there be very few mutations?
Gup20 - Too many mutations at once is usually fatal or renders the creature sterile. In order for genetic mutations to be passed on, they must happen gradually. It is generally accepted that mutation happens on a very low percentage. It is a very long and drawn out process.
JonF - It is also contradicted by all the evidence available.
Coragyps - What's that "directional" doing in there? What does that have to do with "Darwinistic" evolution?
Gup20 - Darwinistic evolution goes from molecules to man - creationists see it as going from the apex of man at creation to the corruped skewed version we have today. This is the reason I say 'direction'. Creationism and Evolution go in opposite directions. Creationists imply that man is constantly de-evolving as genetic copying and mutational mistakes build up.
Well, skin color is actually just the ammount of melanin in your skin. I suppose the genes for it simply tell your skin how much melanin to produce. I suppose the thought would be that it started out somewhere in between and mutation corrupted the regulatory cells in some way.
In other words, you have no idea how it might happen, and you just sort of make it up as you go along. That's what we call an ad-hoc hypothesis; a hypothesis for which there is no evidence and no reason other thatn to try to save your cherished beliefs.
In fact there is almost always no simple one-to-one correspondence between a gene and the characteristics of the organisms that carry that gene. Hox genes are a great example of that. Make a change in a HOX gene and you can get something that doesn't even look like its parent.
Nobody has ever observed anything that might lead to that "theory". Feel free to present non-Biblical evidence, not rhetoric, for it.
My understanding of the creationist theory is that the original kinds were created with full information, as genes mutated, they became non-functional (or malfunctional) thereby creating a loss of information.
Well, that's certainly contradicted by the evidence. If that were true, we would find non-functional versions of all genes scattered throughout all populations. Sorry, there arent many there.
Also, if genes aren't expressed, the _do_ eventually mutate into uselessness; we see that. If your hypotheical rabbits had all the genes required for all different color coats, the ones they weren't using would relatively soon mutate into uselessness. But we see idffernt coat colors and the like appearing all the time. Those genes haven't been lying low, they're new.
Too many mutations at once is usually fatal or renders the creature sterile. In order for genetic mutations to be passed on, they must happen gradually. It is generally accepted that mutation happens on a very low percentage. It is a very long and drawn out process.
OK, I'll give you that one; I thought you were saying that the rate was lower.
It is also contradicted by all the evidence available.
Gup20 - Such as?
Nobody has ever observed any process such as you describe, or any hint that of evidence such a process might exist, or (as I pointed out above) the evidence that such a process would leave behind.
Just a very few examples. Many mutations have been observed and identified that give rise to abilities that were not present in previous generations. In bacteria, the classical example is the nylon eating bug. Another example is Bary Hall's experiments with beta-galactosidase; he deleted this gene from bacteria, and a new set of genes arose by mutation, which created a new irreducibly complex system (see A True Acid Test.
I like pocket mice; light-colored ones live on light-colored rocks and dark ones live on dark-colored rocks. However, populations ofdark ones that live separate from other populations of dark ones have different genes for dark coats! In one population, the exact mutations that cause the dark coat have been identified. See The genetic basis of adaptive melanism in pocket mice
And this isn't even scratching the surface. Everything we have learned about populationj genetics and mutations conflicts with your "theory". Everything.
The genesis of new abilities and characteristics is carried out through mutation and natural selection, not the loss of pre-defined information.