There is a population of snakes with different skin color -yellow snakes -green/brown snakes
Changes in Gene Pool
Less than half the snakes born will survive and the yellow snakes which are visible to predators will start to die out.
The green/brown skin snake has a higher survival rate and is most likely to reproduce offspring and pass on its trait to future generations.
The change in the gene pool is that the population of yellow skin snakes started to decrease and the population of green/brown skin snakes started to increase which meant they survived and reproduced more.