B.7FG Mechanisms of Evolution

B.7FG Mechanisms of Evolution

Picture Vocabulary

© 2012 Rice University - All Rights Reserved

genetic drift

Random changes in the frequency of alleles within a gene pool; greater effect on small

populations © 2012 Rice University - All Rights Reserved

gene pool

The total number of alleles for each gene that is available within a population


mutation

Any change in the sequence of DNA; they can be beneficial, neutral, or deleterious


allele

All of the possible forms of a gene that can occur in an individual


genetic variation

The variety of gene combinations that exist within a population


gene flow

The movement of genes into and out of a population due to interbreeding

between different populations © 2012 Rice University - All Rights Reserved

independent assortment

The random selection of chromosomes from homologous pairs during meiosis to form gametes;

each selection is independent of the other chromosome pairs


crossing over

The exchange of genetic material between homologous chromosomes during meiosis;

contributes to genetic variation © 2012 Rice University - All Rights Reserved

recombination

The process by which genetic material from different individuals becomes combined


theory

A probable explanation of an idea or concept that has been proven multiple times through scientific investigations


endosymbiotic theory

The theory that the eukaryotic cell is actually composed of prokaryotic cells; organelles were

once independent prokaryotes © 2012 Rice University - All Rights Reserved

Oparin-Haldane hypothesis

The hypothesis in which the condition of Earth’s early atmosphere containing ammonia and water led to the

formation of amino acids and eventually the development of life


bottleneck effect

A type of genetic drift in which the population size is greatly reduced due to natural disaster, predation, or habitat loss


emigration

To leave one’s country or region for another


founder effect

A new population is created by a few original founders; it has less genetic variation than the

parent population © 2012 Rice University - All Rights Reserved

immigration

To enter and settle in an area that is not one’s native country


Documents

B.7FG Mechanisms of Evolution