Science Module 7 vocab

natural selection

the driving force behind evolution that promotes adaptation, states that those organisms that are most adapted to the environment wil 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; this is the first thing that must happen for evolution to occur

geographic isolation

reproductive isolation between two populations due to the fact that they have been physically separated by a canyon, river, large body of water or land, etc…in time, may lead to speciation

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 structures

when organisms possess similarities in structure but not necessarily function; infers a common ancestor fairly recent in time

vestigial structure

structures/organs of marginal, if any, importance to the organism; oftentimes, they cause problems; infer that at one time, the structure/organ played a bigger role in evolutionary past

embryology

the science of studying the similarities and differences in embryos between organisms to determine the relatedness or lack thereof between two organisms

Gradualism

a type of evolution that happens SLOWLY but consisently over time

Punctuated equilibrium

a type of evolution where populations show no change for LONG periods of time and then experience rapid change due to events such as reproductive isolation events or mass extinction