fish frogs birds and monkeys all have an embryonic stage in which structures called pharyngeal slits appear on the sides of the throat. Based on this information, which of the following is the best conclusion about the evolutionary histories of fish, frogs, birds, and monkeys?a) The animals evolved from a common ancestorb) The animals did not develop lungs for breathingc) The animals are not adapted to eat the same kinds of foodd) The animals have evolved similar developmental rates from fertilization to birth

Repeated branching events, in which new species split off from a common ancestor, produce a multi-level "tree" that links all living organisms. Darwin referred to this process, in which groups of organisms change in their heritable traits over generations, as “descent with modification." Today, we call it evolution.

A

the principles and empirical processes of discovery and demonstration considered characteristic of or necessary for scientific investigation, generally involving the observation of phenomena, the formulation of a hypothesis concerning the phenomena, experimentation to test the hypothesis, and development of a conclusion that confirms, rejects, or modifies the hypothesis.