Question

Predators and prey are often considered to be locked in an evolutionary arms race in which the prey are always one step ahead of the predators. Explain why prey should typically evolve more quickly than predators. You should provide at least 3 reasons with a brief explanation (15)

Answer 1

Predators are fewer in number when compared to prey because they are higher up the food chain. In a food chain, an organism passes on only part of the energy it receives from food. So with the less energy, each level in a food chain supports fewer individuals than the one below it. For example, prey species often have shorter generation times than the predators, potentially allowing for faster evolutionary rates in prey relative to predators and also they grow more slowly, reproduce less, and so that the population declines. And if predators population increases, they result in a greater strain on the prey population and act as a top-down control, pushing them toward a state of decline. Thus both availability of resources and predators will affect the size of prey population. Another reason that is considered is we already know that the peaks and valleys can be easily observed at roughly 8-10 year intervals. So here the logical and mathematical theory suggest that when prey population are numerous their predators increase in numbers, reducing the prey population and which in turn causes the predator number to decline. The prey population eventually recovers, starting a new cycle. Then the prey population rapidly increase. This is followed by an increase in the predator population. We can simply say as the predators eat the prey, their population goes down because there is less to eat and the predator population also goes down. The most obvious result of the removal of the top predators in the ecosystem is a population explosion in the prey species. And when a prey is abundant in population the predator populations increase because more young are able to survive. More predators kill more prey, which, along with food scarcity, decreases the population.