Question

Some birds in a population have an allele for long beaks and others for short beaks. A drought has caused change in the ecosystem now seeds are harder to find. Birds with longer beaks can dig the seeds out more easily than birds with shorter beaks.

a) Describe and explain which type of bird is most fit for the ecosystem post-drought. (4 pts)

b) How will the drought change the allele frequency in the population? (4 pts)

c) This is an example of natural selection, explain why. (4 pts)

Answer 1

The birds with the longer beaks will be fittest in the environment post-drought because they will be able to gather resources (food) hence survive. This will enable these bords to reach reproductive again and pass down the genes. It is important to note that fitness in nature is determined by the capacity to reproduce.

Natural selection will change the allelic frequency such that the allele for long neck will be more in the population while that of short beaks will reduce. This is because short beaks trait will not be able to reach reproductive age (due to starvation) because of the incapacity to gather food resource hence their genes will keep reducing in the subsequent generations.

Natural selection is a natural selective force that acts on a population and results to variation (differential) in the survival of the individuals in the population due to variations in phenotypes in the population. The most successful traits (phenotype that is best suited for the environment) are able to reach reproductive age, find a mate and reproduce hence leave its genes in subsequent generations