How do you define evolution?
The blood clotting article was very interesting. Is blood clotting considered a mutation or do hemophiliacs just have a deleterious mutation?
From one of the links:
The mosquito link was interesting and it looks beneficial.
I appreciate the info on mutations. Prior to your posts I had only heard of sickle cell resistance as a mutation and then it was not considered beneficial. As I pointed out, the link states this mutation is still not considered beneficial.
While I have no problem seeing some of the mutations as beneficial, I have yet to understand how the mutation supports evolution. I have no problem with a mutation supporting microevolution. But for me it stops there. Do you consider the mutations to support anything other than microevolution?
The mutation is lactose tolerance. Originally we were all intolerant. Regards.
How do you define evolution?
Something like "the creation of existing species from ancient ones thru purely natural means related to variation & inheritance, filtered by natural selection, dumb luck ("genetic drift"), & maybe other factors."
The blood clotting article was very interesting. Is blood clotting considered a mutation or do hemophiliacs just have a deleterious mutation?
The duplications & retargetting of the original genes for pancreatic serine proteases are mutations, yes.
From one of the links:
- Antibiotic resistance in bacteria appears to be a beneficial mutation along with insects becoming resistant to pesticides.
- Bacteria that eat short molecules (nylon oligomers). Is this considered a benefical mutation or a change?
- Sickle cell resistance to malaria is not a beneficial mutation. According to the link "it provides a change", but "is an example where a mutation decreases the normal efficiency of the body".
- Lactose intolerance. I have this "mutation" and don't consider it beneficial! Help me out here. Why is this considered beneficial?
- Resistance to atherosclerosis. This looks like a beneficial mutation.
- Immunity to HIV. I hope I have it.
The mosquito link was interesting and it looks beneficial.
I appreciate the info on mutations. Prior to your posts I had only heard of sickle cell resistance as a mutation and then it was not considered beneficial. As I pointed out, the link states this mutation is still not considered beneficial.
Ah, but that illustrates what I said about traits being beneficial or harmful in context of the organism's environment. The mosquito's mutation is beneficial if they live in areas where pesticide is being sprayed. If they live in pesticide-free areas, then I guess the altered gene would be pumping out enzymes that the mosquito doesn't use. At the least that would be a waste of energy, & I'd expect it to eventually disappear by being selected out of the gene pool. (Like those fish who live in underwater caves, whose eyes don't work anymore.) Same thing as those nylon-eating bacteria. Sickle cell is a recessive trait, and if an African has just one copy of the gene, their red blood cells are just sickle-shaped enough that they have resistance to malaria. The really bad effects of sickle cell anemia kick in when the person has both copies of the sickle cell gene. Only then is it really debilitating. But in a malaria mosquito rich environment, it's an optimal tradeoff.
While I have no problem seeing some of the mutations as beneficial, I have yet to understand how the mutation supports evolution. I have no problem with a mutation supporting microevolution. But for me it stops there. Do you consider the mutations to support anything other than microevolution?
Yes. Enough mutations of the right types would eventually make the separated population incompatible with the original one. Creationists assert that there must be some as-yet-unseen barrier on a genetic level against speciation, but they've never shown that such a barrier actually exists. Meanwhile there are all those speciations that have either been seen in "real time" or are known to have occurred since historical times.