Mutations Made Easy

quote:

---

If two people with the Sickle Cell gene procreate, then the progeny will be affected by the full blown disease. Therefore, the immunity will be bred out of existence when more, and more people populate. Where's the ambiguity in that?

---

No ambiguity but a big error. Basic genetics - and I mean that it would be nothing new to Mendel - says that if two heterozygous individuals breed, statistically, half of their offspring will also be heterozygous. Only 1/4 of their offspring would have the full-blown condition (the other 1/4 would be "normal" - no sickle-cell at all).And you will have to explain why
this article shows that a beneficial mutation would not be beneficial. It looks like a confused mess to me.
nThis message has been edited by PaulK, 05-08-2006 03:52 PM

quote:

---

As it relates to biology, the constant transferring of genes would not lead to an upgrade of information, but a steady, gradual decline. I believe we are becoming less and less pure, genetically speaking, which is clearly the opposite. Does natural selection exist? Yes. And it does help in slowing this inevitable process down. But nonetheless, ultimate corruption is an inevitable outcome. Do you understand now my mentioning for entropy?

---

What you are talking about is not thermodynamic entropy which makes your reference to Morowitz irrelevant. It isn't really the entropy of information theory either (and it wouldbe no good for your argument even if it was - there is no equicalent of the 2LoT for information theory).So again, it seems that you have made a mistake.s

quote:

---

I disagree. The majority of affected people come from African decent. Lets say we have 100 carriers, 50 male, 50 female. Then we have 100 with full-blown SCA, 50 male, 50 female. All it takes is for these people to get it is to procreate in order for it to proliferate in their progeny. Heterozygous becomes homozygous in the offspring and that's when people start dying.

---

How do you get your 100 individuals with full-blown SCA ? From the figures which you agreed with only 25% of the offspring would have full-blown SCA. Are you assuming that each couple has an average of 4 children ? If so why don't you mention that you should also have 200 new carriers and 100 people without the SCA gene at all ?If you actually do a proper analysis you will see that if your initial population is entirely heterozygous for the SCA gene then the next generation will also have an average of 1 copy of the gene per individual (the distribution wills change so that many will have 2 copies or none). The only way for that to change is if the individuals with 2 copies are more successful at breeding ("fitter") then those with none. i.e. only if full-blown sickle-cell is better - or less bad - than the lack of malaria resistance in the "normal" population.(And, of course, out of malarial areas the lack of resistance is not a disadvantage at all - while full-blown SCA is unambiguously bad).l