Recombination in dihybrid crosses
You have screened for several new recessive mutations in a species of wasp.

Wasps homozygous for apricot (aa) have pale orange eyes. (Wild-type eyes are brown.)
Wasps homozygous for blunt (bb) have short wings. (Wild-type wings are long.)
You make a pure-breeding double-mutant (apricot, blunt) line and cross it with wild-type wasps. The F1 is wild-type in appearance.

You testcross the F1 dihybrids with the double-mutant line

Which of the following observation darwin shape his concept of descent with modification? a) species diversity declines farther from the equator. b) fewer species live on islands than on the nearest continents. c) birds live on islands located farther from the mainland than the bird's maximum nonstop flight distance. d) south american temperate plants are more similar to the tropical plants of south america than to the temperate plants of europe. e) earthquakes reshape life by causing mass extinctions.