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gluadys -> RE: Chimpanzees and humans share a common ancestry? (8/9/2008 7:08:56 PM)
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quote:
ORIGINAL: Consecrated2God
That's Greek to me, glaudys. You'll have to explain that in non-scientific terms if you want me to understand it. <smile>
Ok.
Let's start with the pseudogene. Do you ever wonder why your dog or cat does not need to drink orange juice? Like most mammals, they have a gene which directs the formation of a protein whose function is to manufacture Vitamin C. They do not need an external source of Vitamin C because it is produced by their own bodies.
As you know, this is not true of us. Nor is it true of chimpanzees and other hominids. All of us need to eat fruit and vegetables which provide Vitamin C for us.
Is it because we don't have the gene? No, we have the gene. But it doesn't work. A mutation in the gene led to a corruption of its ability to produce the necessary protein. Furthermore, exactly the same mutation is found in other hominids.
Now a lot of things can make a gene non-functional. In fact there is another mammal which does not produce its own Vitamin C either. And for the same reason. The gene is damaged. But, it is damaged in a different way than in hominids. IOW there is more than one way to make a gene stop working.
So we have a situation in which not just our species, but all the other species in the hominid family, not only have a defective Vitamin C producing gene, but all show the same defect.
Now what can we say from a creationist perspective?
Was it God's intention from the beginning that we not produce our own Vitamin C like other mammals? If so, why is the gene there at all? Wouldn't it make more sense to just leave it out than to put it in and then disable it? Would God intentionally create us with a broken gene?
And why disable, in the very same way, the same gene in other hominids, but differently in a non-hominid mammal? And why only in this small group of mammals?
From an evolutionary perspective, the solution is simple. The whole mammalian kind started out with a functioning gene. As mammals diversified into different lineages, the gene experienced a disabling mutation twice: once in the hominid family and once in a different lineage. But while both led to non-production of Vitamin C, they did so in different ways.
Within the hominid family, it was a common ancestor which experienced the mutation. The species survived because its life-style gave it access to lots of fruit, so losing the ability to produce its own Vitamin C was not a problem. So the disabled gene was passed to all its descendants as they diversified into different species, and we are one of those species.
Like to do ERVs next? They are a bit more complicated, but raise some of the same questions.
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