unit 4

an inherited characteristic that enhances and organisms ability to survive and reproduce in a particular environment

period of evolutionary change in which groups of organisms form many new species whose adaptations allow them to fill new or vacant ecological roles in their communities.

a protist that produces its food by photosynthesis

a two-part latinized name of a species; for example, homo sapeian

genetic drift resulting from a drastic reduction in population size; typically, the surviving population is no longer genetically representative of the original population

a group of species that includes and ancestral species and all its descendants

an approach to systematics in which common descent is the primary criterion used to classify organisms by placing them into groups called clades

a process by which the mitochondria and chloroplasts of eukaryotic cells probably evolved from symbiotic associations between small prokaryotic cells living inside larger cells

descent with modification; the idea that living species are descendants of ancestral species that were different from present-day ones; also the genetic changes in a population over generations

a branching diagram that reflects a hypothesis about evolutionary relationships among groups of organisms

it irrevocable loss of a species

genetic drift that occures when a few individuals become isolated from a larger population, whit the result that the composition of the new population's gene pool in not reflective of that of the original population

the transfer of alleles from one population to another, as a result of the movement of individuals or their gametes

all the alleles for all the genes in a population

a change in the gene pool of a population due to chance; effects of genetic drift are most pronounced in small populations

similarity in characteristics resulting from a shared ancestry

a geographic region in which members of different species meet and mate, producing at least some hybrid offspring

evolutionary change on a grand scale, encompassing the origin of new taxonomic groups, evolutionary trends, adaptive radiation, and mass extinction

a change in a populations gene pool over generations

in scientific studies, the search for the least complex explination for an observed phenomenon

an organism that has more than two complete sets of chromosomes as a result of and accident of cell division

a member of the Kingdom Protista. most protists are unicellular, though some are colonial or multicellular

a protist that lives primarily by ingesting food;a hererotrophic, "animal-like" protists

marked differences between the secondary sex characteristice of males and females. pecocks

a close association between organisms of two or more species

a named taxonomic unit at any given level of classification

the branch of biology that identifies, names, and classifies species