The graphs here show the distribution of beak depths for the ground
finches on Daphne Major, an island in the Galapagos. The bird beaks were
measured over a multi-year study, including a time period before and after
a drought. The drought reduced the supply of seeds and left most of the
seeds as thick-walled nuts that survived the drought. Analyze the data and
select the claim about natural selection and genetic diversity that is
supported by the data.

Natural selection tends to reduce genetic variation, as there was a smaller distribution
of beak depths, but it tends to select for the most fit phenotypes, as there was an
increase in average beak depth after the drought.

Natural selection tends to increase genetic variation, as there were more ground
finches after the drought, and it tends to select for the most fit phenotypes, as there
was an increase in average beak depth after the drought.

Natural selection tends to reduce genetic variation, as there was a smaller distribution
of beak depths, but it tends to select against the most fit phenotypes, as there was an
increase in average beak depth after the drought.

Natural selection tends to increase genetic variation, as the average beak size
increased after the drought, but it tends to select against the most fit phenotypes, as
there was a decrease in population size for the finches after the drought