Chapter 22

Seite 1

Descent with modification

Evolution:

Pattern - observations of natural world changing over time

Process - mechanism that cause observed changes

1. Diversity of Life

2. Differences and similarities among organisms

3. Characteristics of organisms, both useful and non-useful

- CHANGE

- Process of descent with modification from common ancestors

Descent - cumulative transmission of genetic info

Modification - alteration in the composition of genetic info

Common ancestry - all of life shares a history of common ancestors

Anatomists: Aware that the diversity of life has common themes (HOMOLOGY)

Biogeography: Range and geographic distribution of life

Artificial Selection: Breeder chooses traits to perpetuate by choosing parents

Fitness: Survival and reproductive success of an individual relative to other members

Adaptations products of natural selection: Helps organism be more suited to environ

Evidence for Evolution:

Biogeographical Evidence - Range and distribution of plants and animals

Anatomical Evidence - Vertebrate forelimbs;homologous structures;Vestigal structures(lack function in descendants);Embryologic development(shared through common AN)

Biochemical Evidence - DNA,ATP,Genetic code

Fossil Record

Cause of resemblance:

Convergent evolution - evolution of analogous features in distantly related groups

Analogous (similar) traits arise when groups adapt to similar environments in similar ways.