BIOL-1040 Chapter Notes - Chapter 13: Multicellular Organism, Zygosity, Habitat Destruction
Document Summary
Evolution: the idea that living species are descendants of ancestral species that were different from present-day ones. Fossils: imprints or remains of organisms that lived in the past. Homology: the similarity of organisms developed from common ancestors: homologous structures: help to determine the similarities that organisms have structurally, i. e. limbs, embryos, and ways of movement. For e(cid:454)a(cid:373)ple, the pel(cid:448)is or leg (cid:271)o(cid:374)es of (cid:449)hales a(cid:374)d their (cid:449)alki(cid:374)g ancestors. Evolutionary tree: help to look at the patterns of descent from common ancestors and homologous structures, which are made into a tree-like diagram: for example, the picture below shows an evolutionary tree. Each branch point represents the common ancestor of all species that descend from it. Most trees are supported by the strong combinations of fossil, anatomical, and molecular data: evolutionary trees are hypotheses reflecting our current understanding of patterns of evolutionary descent. Individuals do not evolve: natural selection can amplify or diminish only heritable traits.
