00:01
Hopefully all of us will grow up and live to a nice ripe old age.
00:06
However, with age can come other problems, achy back, achy knees.
00:11
I know my parents complain about that.
00:14
But other diseases associated with old age, for example, like alzheimer's, also occur.
00:23
Now alzheimer's is a disease that progressively gets worse and you lose your memory and other mental functions and it can be a very tragic and sad disease to watch someone go through.
00:32
Through or to live through.
00:35
And so sometimes you might ask yourself, well, why hasn't natural selection gotten rid of alzheimer's? doesn't it want all organisms to be as fit and as healthy as possible? so why can't, is it possible that natural selection might be making humans who are more resistant to alzheimer's and won't develop it when they're older? the unfortunate answer to that is no, at least not.
01:04
Directly and so we can illustrate that with the different disease called huntington's.
01:12
Now this is another very tragic disease that causes progressive nerve damage which affects movements which affects mental processes and it is an autosomal dominantly inherited condition and what that basically means is if you have one parent who doesn't have it one parent who does and they have you, you have a 50 % chance of getting it.
01:45
If both of your parents have it, you have a 100 % chance of getting it...