Question

62. A population of a grasshopper species in the Kansas prairie has two color phenotypes, with 90% of the grasshoppers green and 10% brown. Typically in the last century, the prairie receives adequate rain to maintain healthy green grass, but for the last decade the prairie suffers a severe drought and is also invaded by a bird that eats grasshoppers.

Briefly explain in terms of the four parts of natural selection listed below how the population of the grasshopper species would be expected to change during the drought years.

overproduction -

variation -

competition & survival -

differential reproduction -

Answer 1

Overproduction:

Overproduction is a process by which an organism produces more and more offsprings than can possibly survive. Now if the resources for living are limited then there will be struggle for living in between those offsprings. Those who are able to survive or adapt the environmental change and in this case if those surviving grasshoppers learn the process of avoiding predatory birds they can pass their genes to next generation.

Variation:

An organism's genome through out life interacts to the environment and random mutation in the genome causes new traits to evolve, variation comes like this. And the one with better survival possiblity transfer it's evolved gene to the next generation. Changes in environment can create mutational changes in the grasshoppers to rely on other food resources and to avoid the predatory birds.

Competition and survival:

In this case the competition is within the species. If the two coloured phenotypes overproduce or those with better traits to survive the severe drought or those who wins the limited food resources during drought will reproduce and pass the trait to the offsprings.

Differential reproduction:

The process by which organism with better adaptation to the environment survive up to reproductive age and produce offsprings for next generation. In this case, those grasshoppers who can survive the drought or learn to avoid those predatory birds can survive up to reproductive age and reproduce.