Decrease in hetrozygous allele frequency

[fran008]

Can someone explain why continual mating in a small population leads to a decrease in hetrozygous individuals and an increase in homozgous?

Also why is it the same when considering self fertalization?

Thanks for your help

[Johannes]

good question, as fare as i remember it is due to genetic drift which occurs due to inbreeding in a small population, its the same with plant self fertilization in plants.

The result may be the greater occurence of homozygouse recessive alleles, which have are ore likely to be delitirous, since there is less selection pressure on them.

hope that helps johannes

[fran008]

yes tnx loadz johannes!

[rambo]

Less genetic diversity therefore the end products will be similar. I understand that there still will be alot of different possibilities for gene coding, but if less amount of genes are in the equation then the more the genes will be used. The frequency of that gene will show up more. If alot of genes, like in a diverse area, are added then they have X times more possibilities for coding. Therefore the chance of one gene lasting all the way down the list is less, the list is alot longer than a small community.

[rambo]

Less genetic diversity therefore the end products will be similar. I understand that there still will be alot of different possibilities for gene coding, but if less amount of genes are in the equation then the more the genes will be used. The frequency of that gene will show up more. If alot of genes, like in a diverse area, are added then they have X times more possibilities for coding. Therefore the chance of one gene lasting all the way down the list is less, the list is alot longer than a small community.

remember when heterozygous genes are passed down they soon become recessive because they are bound to find a match