African elephants once existed in large populations across the African continent. Elephants use their tusks to dig for water and food. Humans hunt and kill elephants for their tusks. Habitat loss and fragmentation have also reduced the total number of elephants and the size of elephant herds. Scientists estimate that the number of African elephants has decreased from several million to several hundred thousand. Population sizes range from over 100,000 individuals in Botswana to approximately 100 individuals in northern Cameroon. Scientists have also found that the frequency of elephants that never develop tusks is increasing. Select all the statements that describe probable effects of poaching and habitat fragmentation on clephant evolution
a. The elephant population in Botswana will experience high levels of genetic drift.
b. The poaching of elephants for their tusks is leading to the evolution of tuskless elephants.
c. Having tusks does not provide a selective advantage to African elephants.
d. Habitat fragmentation leads to decreases in population size and increases in genetic drift.
e. The elephant population in Cameroon will experience high levels of genetic drift.