biology assessment: chapter 14: evolution
Charles Darwin's main focus was on the gradual process of adaptation within populations. This form of change _____
cannot account for increases in species diversity over time
Two animals are considered members of different biological species if they _____.
are male and female, but cannot interbreed
Often, the morphological species concept is used to define and describe species. Why?
This is the most convenient way of identifying species, and it is one of the few ways to identify fossil or asexual species.
The following options are all reproductive barriers. Which one is an example of a prezygotic barrier in which the two different species do mate?
Two dragonfly species regularly mate, but their gametes are incompatible.
Which of these is an example of temporal isolation?
One species is diurnal (day active) and mates at high noon; the other is nocturnal (night active) and mates at midnight.
What is the first step in allopatric speciation?
Sympatric speciation is _____.
the appearance of a new species in the same area as the parent population
_____ generated many key crop plant species in the past, and continues to be an important method for plant geneticists today.
Sympatric speciation by polyploidy
The evolution of numerous ecologically diverse species in a relatively short time period, such as Darwin's finches, from a single ancestor is called _____.
According to the _____ model, evolution occurs in spurts: Species evolve relatively rapidly and then remain unchanged for long periods.