Barbarian explains:
Actually, cheetahs likely don't have any greater "load" than humans do. The real problem is a severe lack of genetic diversity. They are so alike that apparently, they can all serve as tissue donors for each other.
It's very well studied. Probably the best-studied example of reduction in genetic diversity in a large mammal. edit: Sequencing of the entire Cheetah genome is now underway.
I thought you were a bit off your form.
Hmm... I must have missed that one. Tell me about it, and the evidence for it.
Odd then, that scientists don't think so. Let's take a closer look at it. Can you lay out the issue for us?
Well, a surprising amount of non-coding DNA actually does nothing that removal compromises in an organism.
Nature 431, 988-993 (21 October 2004)
Megabase deletions of gene deserts result in viable mice
Marcelo A. Nóbrega2, Yiwen Zhu2, Ingrid Plajzer-Frick, Veena Afzal & Edward M. Rubin
The functional importance of the roughly 98% of mammalian genomes not corresponding to protein coding sequences remains largely undetermined1. Here we show that some large-scale deletions of the non-coding DNA referred to as gene deserts2, 3, 4 can be well tolerated by an organism. We deleted two large non-coding intervals, 1,511 kilobases and 845 kilobases in length, from the mouse genome. Viable mice homozygous for the deletions were generated and were indistinguishable from wild-type littermates with regard to morphology, reproductive fitness, growth, longevity and a variety of parameters assaying general homeostasis. Further detailed analysis of the expression of multiple genes bracketing the deletions revealed only minor expression differences in homozygous deletion and wild-type mice. Together, the two deleted segments harbour 1,243 non-coding sequences conserved between humans and rodents (more than 100 base pairs, 70% identity). Some of the deleted sequences might encode for functions unidentified in our screen; nonetheless, these studies further support the existence of potentially ‘disposable DNA’ in the genomes of mammals.
That's a lot more non-functional stuff than I would have expected.
You have a huge number of "slightly deleterious" alleles, but fortunately, the great majority of them are recessive, so unless you breed with a close relative, your offspring are unlikely to suffer thereby.
Would have been. But God had a solution for that, too.
Barbarian observes:
Understand that "mitochondrial Eve" is not represented to be the first woman. She would merely be the last woman who is the ancestor of all living humans. Likewise with "Y Adam." But that isn't a sure thing for reasons that are probably obvious to you. Mostly it's like a town with lots of Joneses and Murpheys. One generation, the Joneses happen to have only females. So, if we go just by the "allele" for last names, then we'd suppose that the Joneses all died out. I blame the publicists who coined the "Eve" thing; it invites misunderstanding.
Don't see how. Can you elaborate?
The best estimate for Y-Adam is now 60,000 to 90,000 years ago. That's using both genetic marker and molecular clock data. Both are of course, matters of probabilities, and both depend on a number of assumptions which are likely, but not absolutely certain.
True. But not the YE account. There are some forms of creationism that would be consistent with this data.
Actually, cheetahs likely don't have any greater "load" than humans do. The real problem is a severe lack of genetic diversity. They are so alike that apparently, they can all serve as tissue donors for each other.
It's very well studied. Probably the best-studied example of reduction in genetic diversity in a large mammal. edit: Sequencing of the entire Cheetah genome is now underway.
I thought you were a bit off your form.
Hmm... I must have missed that one. Tell me about it, and the evidence for it.
Odd then, that scientists don't think so. Let's take a closer look at it. Can you lay out the issue for us?
Well, a surprising amount of non-coding DNA actually does nothing that removal compromises in an organism.
Nature 431, 988-993 (21 October 2004)
Megabase deletions of gene deserts result in viable mice
Marcelo A. Nóbrega2, Yiwen Zhu2, Ingrid Plajzer-Frick, Veena Afzal & Edward M. Rubin
The functional importance of the roughly 98% of mammalian genomes not corresponding to protein coding sequences remains largely undetermined1. Here we show that some large-scale deletions of the non-coding DNA referred to as gene deserts2, 3, 4 can be well tolerated by an organism. We deleted two large non-coding intervals, 1,511 kilobases and 845 kilobases in length, from the mouse genome. Viable mice homozygous for the deletions were generated and were indistinguishable from wild-type littermates with regard to morphology, reproductive fitness, growth, longevity and a variety of parameters assaying general homeostasis. Further detailed analysis of the expression of multiple genes bracketing the deletions revealed only minor expression differences in homozygous deletion and wild-type mice. Together, the two deleted segments harbour 1,243 non-coding sequences conserved between humans and rodents (more than 100 base pairs, 70% identity). Some of the deleted sequences might encode for functions unidentified in our screen; nonetheless, these studies further support the existence of potentially ‘disposable DNA’ in the genomes of mammals.
That's a lot more non-functional stuff than I would have expected.
You have a huge number of "slightly deleterious" alleles, but fortunately, the great majority of them are recessive, so unless you breed with a close relative, your offspring are unlikely to suffer thereby.
Would have been. But God had a solution for that, too.
Barbarian observes:
Understand that "mitochondrial Eve" is not represented to be the first woman. She would merely be the last woman who is the ancestor of all living humans. Likewise with "Y Adam." But that isn't a sure thing for reasons that are probably obvious to you. Mostly it's like a town with lots of Joneses and Murpheys. One generation, the Joneses happen to have only females. So, if we go just by the "allele" for last names, then we'd suppose that the Joneses all died out. I blame the publicists who coined the "Eve" thing; it invites misunderstanding.
Don't see how. Can you elaborate?
The best estimate for Y-Adam is now 60,000 to 90,000 years ago. That's using both genetic marker and molecular clock data. Both are of course, matters of probabilities, and both depend on a number of assumptions which are likely, but not absolutely certain.
True. But not the YE account. There are some forms of creationism that would be consistent with this data.