5.11 Breeding Animals

- The animal in the video is a cow. The desired characteristic is milk yield.
- The earliest farmers notice that a few cows will produce a small amount of milk each time. around 50 ml each time that they are milked.
- Other cows, a few, will produce 150 ml of milk
- Most cows produce 100 ml of milk.
- The farmer will collect all the milk
- He chooses the cows that make 150 ml of milk to become his breeding cows.
- In the next generation of cows, we find out that a few cows produce 100 ml of milk, very few produce 200 ml of milk and the majority produce 150 ml of milk
- The farmer selects his breeding cows from the one that produce 200 ml to become the breeding population
- perhaps, in the next generation, a few cows will produce 150 ml of milk, most cows will produce 200 ml and few produce 250 ml
- as we progressively select, we change the desired characteristic. We are able to develop the desired characteristic by selective breeding
- for this to work, milk yield must be genetic - under the control of genes.