im not using the right word here and im not sure what you call it...im talking about 'sterility' in the sense that a cat and dog cannot produce offspring. I thought it was called sterility but obviously any individual can be sterile.
Even if you use more accurate terminology such as 'interfertility', the reproductive compatibility of two organisms to produce viable fertile offspring. It doesn't change the fact that interfertility is not a measure of relatedness, only of specific genetic compatibility. In some cases genetic incompatibility can be established by very few mutations, which is why it isn't a good measure of relatedness.
The essential reason why a cat and a dog can't successfully interbreed and why 2 genetically incompatible people cant interbreed is the same, genetic incompatibility, in the case of the cat and dog the incompatibility is considerably wider spread because they have had time to evolve in different directions since they last had common ancestors within one breeding population. Over this time their chromosomal organisation may have changed significantly, including the number of chromosomes, the arrangement of genes on the chromosomes and the specific genes themselves. All of these differences may contribute to the genetic incompatibility.
the breeding experiments im talking about are the ones where scientists have tried to keep changing various animals and plants to try and develop new forms of life.
Oh, you mean fictional ones made up by creationists, thanks for clearing that up. None of the things Bergman refers to were experiments with the intention of developing 'new forms of life'.
But man and ape are said to be related and yet they cannot produce offspring...not even hybrids.... so how are they related?
Just blindly repeating the same question doesn't help, They are genetically related, you just agreed genetics can tell us about relatedness, but now you are taking it back and saying it can't because ... well no reason really, except that you don't like evolution. I have explained twice now that producing offspring is not the measure of relatedness, do you get it yet? No matter how often you try to claim it is you will never be right.
If we cant do it deliberately, what makes you think nature can do it accidently?
Apart from creationist lies what make you think people have been trying to do it deliberately? Plus nature has had a lot longer and a lot more resources.
But if your version of evolution includes the idea that species can develop so much change that they become a new species, then i dont believe that there is any evidence for that.
Thats because you think becoming a new species means a cat will become a dog because you're understanding of evolution is based on creationist propaganda rather than, say, actual evolutionary theory.
this is in perfect harmony with what breeding projects have found with regard to species. Species reproduce according their parents.
That is what evolution says as well, it just also says that the offspring can differ slightly from their parents which is indeed what we see.