Consider four species of conifers. species a and b are sister species. species c and d are also sister species. the clade containing species a and b is a sister to the clade containing species c and d. not counting the root as a node, how many nodes would be found in a phylogenetic tree of species a, b, c, and d?

According to the cladogram, which organisms have roundworms as a common ancestor?

In "the man in the water," what was the remarkable occurrence that rosenblatt reported?

What is a population? a. all the members of the same species living in the same ecosystem at the same time b. the number of a species living in the same ecosystem over a period of time c. the total number of organisms living in an ecosystem at a point in time d. all the members of a food web in the same ecosystem