Human Evolution in Italy
Evolution has been controversial topic. Bringing out the best scientist vs. the most prestigious religious figures in the argument of Evolution and Intelligent Design. With all this controversy surrounding Evolution some forget to the amazing scientific studies in the field. Within the past 20 years a mutation was discovered in a small Italian community that decreases the risk of arteriosclerosis, heart attack and stroke. The mutation was discovered to be in a protein, called Apolipoprotein AI. This is a major component in HDL cholesterol which is sometimes referred to as the "good" cholesterol.
Cholesterol is a lipid molecule that is transported in bloodstream in the form of lipoproteins. There are two forms of lipoproteins found in the human body, LDL(Low Density Lipoprotein) and HDL(High Density Lipoprotein). HDL is referred to as the "good" cholesterol because it removes cholesterol from the bloodstream to the liver. LDL does a poor job of removing cholesterol and can leave deposits of cholesterol on artery walls. These deposits can lead to increased risks of arteriosclerosis, heart attack and stroke.
The mutated form of this protein has been named Apolipoprotein AI Milano(now referred to as Apo-AIM). Apo-AIM has been shown to improve biological function of HDL. As described in a Guido Franceschini article the HDL molecules were increased in size an lower cholesterol more effeciently than normal HDL. It has been shown in lab mice that the mutant allele will display benefits in heterozygous carriers but displayed better in homozygous carriers. The chances of a being a homozygous carrier is 1/3700 and humans carrying the mutation have been confirmed heterozygous for the allele. The individuals are known descendants of a 18th century couple who passed the mutation on to there kin. This mutation is a present day example of evolution in humans.
Being able to identify a single mutation that benefits all carriers in humans is a monumental discovery in the field of evolutionary sciences. Apo-AIM is a perfect example of evolutionary processes in humans as it is a mutation changing the inherited traits of the offspring in this population. This protein is just one mutation leading humans in a forward progression of the species. Mutations such as these could lead to species wide mutation after eons of reproduction since there are no downfalls and only benefits to this protein. Discoveries like these can also be studied in genetics for possible insertion in embryonic development but that is a whole other discussion in itself.
Posted by John Reilly
posted by PWH @ 3:04 PM
4 comments
4 Comments:
It was an interesting article. I was a little confused as to how it is significant in the study of evolution. It seems like just genetics when you say it is a mutation (which I always kind of thought of as "accidental"). Did you read anywhere how Apo-AIM improves the biological function of HDL? Does it just speed up HDL's removal of cholesterol or does it also help with some other aspect?
Posted by: Christine McConville
It's nice to see with all of our interfereings with evolution that it still finds ways to persevere. As a species we have definitely hindered our ability to evolve as a species by eliminating survival of the fittest. In most cultures we help those who cannot help themselves or we use medicine to save somebody dieing from a genetic defect. Are there any downsides from this mutation?
-Tom Farese
This post was very interesting. I have not heard much about recent evolutionary findings, so it's refreshing to hear something like this. I agree that it is neat that with all the tapering humans do with evolution in general that it does indeed continue to manifest. The aricle was well written and the content was very interesting.
Post By: Meaghan Elliott
When I was in high school I worked in a lab where we studied the effects of Apolipoprotiens in mice. We studied Apo-E 4 and it's correlation to memory and motor skills in aged mice since it is a protein which also occurs in humans and has been tied to Alzheimer's disease. I'm wondering if you're talking about the same protein or a different one. As I understand it Apo-E exists in all humans but has 4 variations within it (we also tested a knock-out mouse without the protein - he was not healthy). I'm curious as to how this is an evolutionary study. Please explain because this is the first I've heard anything about apolipoproteins since working in my lab.
Posted by Sarah Kaz
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