If you looked at the mouthparts of a grasshopper, a butterfly,
and a mosquito, you would see that they are very different.
Grasshopper mouthparts are adapted for cutting and grinding up
tough plant food; butterflies have a single, long, curled sucking
tube for drinking nectar; and mosquitoes have both a sucking tube
and needlelike structures for piercing skin. In spite of their
differences, though, all three insects (indeed, all 900,000 species
of insects!) have mouthparts composed of the same anatomical
structures in the same positions. These facts tell you that
insect mouthparts are homologous and demonstrate that all
insects inherited the same basic anatomical structures from a
single common ancestor.
insect mouthparts are vestigial structures inherited from a
common ancestor in which they were useful.
insect mouthparts are developmental homologies that demonstrate
common ancestry for all insects.
DNA sequence homology among insects is very strong.
insects are unrelated; their mouthparts represent adaptations
to their different ecological requirements.
The collection of _____ in a population constitutes that
population's gene pool.
genes
genotypes
phenotypes
alleles
chromosomes