New News Biology #58

Selective Breeding

It is basically taking the best plants or animals and breeding them together and hoping to get better offspring.

The practice started quite a while ago, since we changed to agriculture which means that selective breeding has been used for thousands of years. We use it for breeding crops, flowers, pets, and even cows so that they can produce more milk.

How does it work?

We take the best plants from our population

Then we breed them together to (hopefully) get a better 2nd generation.

We don’t just stop here. We breed the best from the 2nd generation and produce a (hopefully) even better third generation.

Drawbacks of selective breeding:

Reduces the gene pool (collection of different alleles) of the population. This happens because when we are doing selective breeding, we are essentially selecting certain alleles that code for traits we want.

Risk of inbreeding - the offspring are prone to certain diseases or inherited defects, because the best individuals are closely related and have a smaller pool of alleles

Less variation within the population - because the gene pool is so small, one new pathogen could destroy the farmer’s entire crop at once.