Science module 7

Natural Selection

States that those organisms that are most adapted to the environment will survive, reproduce, and pass on their genes.

Speciation

When a new species arises.

Reproductive Isolation

Happens when two populations become unable to reproduce or swap their genes.

Geographic Isolation

Reproductive isolation between two populations due to the fact that they have been physically separated.

Adaptation

Any inherited characteristic that increases an organism's chance of survival.

Relative Dating

A method of dating fossils that uses known ages of rock strata above and below the fossil to give the best estimate of when that organism once lived.

Radiometric Dating

A method of dating geological or archeological specimens by determining the relative proportions of particular radioactive elements present in a sample.

Half-life

The amount of time it takes for 1/2 of a certain radioactive isotope to decay.

Intermediate (Transitional) Fossils

Fossils that link one species to another.

Homologous Structure

When organisms possess similarities in structure but not necessarily function.

Vestigial Structure

Structures/organs of marginal, if any, importance to the organism.

Embryology

The science of studying the similarities and differences in embryos between organisms to determine the relatedness.

Gradualism

A type of evolution that happens SLOWLY but consistently over time.

Punctuated Equilibrium

A type of evolution where populations show no change for LONG periods of time and then experience rapid change.