Why do chordates have stronger mus cles than members of other phyla?

How does natural selection change thephenotypes within a population over time?

Which of the following factors would not contribute to allopatric speciation? a) a population becomes geographically isolated from the parent population.b) the separated population is small, and genetic drift occurs.c) the isolated population is exposed to different selection pressures than the ancestral population.d) different mutations begin to distinguish the gene pools of the separated populations.e) gene flow between the two populations is extensive.

Look at the photo of the leaf, which term best describes this leaf ? a-simple.b-parallel.c-lobed.d-tooth.