52) The basic units that evolve species.
53) There can be : 1380848.
52) The basic units that evolve are species.
53) There can be more than two varieties of alleles for a particular gene in a population.
54) A small minority of mutations is adaptive, providing an improvement to the gene pool of the population.
55) Genetic drift has a much more significant effect on small populations than on large populations.
56) Without mutation, evolution would eventually cease, because mutations create the variation that evolution acts upon.
57) A population of salamanders migrates from a sand beach to a pebble beach and evolves over many generations from a solid color to speckled coloration. This process is called stabilizing selection.
58) If a species of bird with an intermediate beak size evolves into two varieties, one with large beaks and one with small beaks, this could result from disruptive selection.