Ch. 22: Natural Selection

Individuals from one species cannot breed with another species

Morphological similarities

Species change over time (George Buffon), growth of populations limited by famine and disease (Thomas Malthus)

Earth in the past changes in the same way and at the same rate as it does in present

Identified descent between fossil taxa and living species, change slow and gradual

1. Individuals change their phenotype through use and disuse
2. These modifications are encoded in the genotype and passed to offspring

False, population changes, not the individual

All life has a single origin (DNA, transcription, translation), Genetic differences accumulate between populations

Constant, random production of modified genes by changing DNA sequences. Can be beneficial, neutral, or deleterious

Crossing over, independent assortment of chromosomes

Half genetic sequence from each parent

Individuals in population vary, variation is heritable, frequency of characteristics will change in population over time

Adaptive process where populations change with the environment.

Environmental resources are limited

It is most important to survive long enough to reproduce, not just to survive.

An organism's ability to pass genetic material to offspring, close kin that reproduce also contribute

1. Extinction occurs (no fixed scale of nature)
2. similar species are found in same geographic area today
3. unrelated species use similar strategies to deal with environment (homology)

Selective breeding for a desired trait (ex. domesticated animals), big changes in a short period

Structures that have reduced or no function, but are similar to functioning traits in closely related organisms, provide evidence of a common ancestor

Transitional features found in fossil record

Adaptations do not occur because organisms want/need them

It can be impossible to maximize 2 qualities so most fit organisms have a compromise (ex. egg size in hens)