DAT Biology Evolution

evolution

the change in the genetic makeup of a population with time

Lamarckian Evolution

the discredited theory of evolution stating that the amount of change was based on the use or disuse of an organ

acquired characteristic

A characteristic that an organism developed in their lifetime based on their surroundings; not inherited

fitness

Ability of an organism to survive and reproduce in its environment

natural selection

A natural process resulting in the evolution of organisms best adapted to the environment.

overpopulation, variations, competition, natural selection, inheritance of variations, speciation

list Darwin's 6 basic agents leading to evolutionary change

speciation

the evolution of new species

species

groups of individuals that can interbreed freely with each other but not with members of other groups

genetic variation, changes in environment, migration, adaptation, natural selection, genetic drift, isolation

list 7 factors that can lead to speciation

demes

before speciation, small, local populations called _____ often form within a species

phylogeny

The study of evolutionary relationships among organisms

convergent evolution

evolution in which two species from different ancestors develop similar traits due to similar environments (i.e. sharks and dolphins)

parallel evolution

evolution in which two species from a similar, recent ancestor develop similar traits due to a similar environment

divergent evolution

evolution in which species with a shared ancestor develop differing traits due to dissimilarities between their environments

adaptive radiation

An evolutionary pattern in which many species evolve from a single ancestral species

niche

An organism's particular role in an ecosystem, or how it makes its living.

population

all members of a particular species inhabiting a given location

gene pool

the sum total of all the alleles for any given trait in the population

gene frequency

the decimal fraction representing the presence of an allele for all members of a population that have a particular gene

p

letter representing the dominant allele when discussing gene frequency

q

letter representing the recessive allele when discussing gene frequency

Hardy-Weinberg equation

equation used to determine gene frequencies in a large population in the absence of microevolutionary change

p²+2pq+q²=1

write out the Hardy-Weinberg equation

microevolution

Changes in a population's gene pool from generation to generation

natural selection

idea that genotypes with low adaptive values tend to disappear

natural selection, mutation, assortive mating, genetic drift, gene flow

list 5 factors causing deviations from the ideal conditions necessary for the Hardy-Weinberg equation

assortive mating

the mating of phenotypically similar organisms

genetic drift

A change in the gene pool of a population due to chance

sexual selection

when individuals choose mates based on phenotype and proximity

founder effect

Genetic drift that occurs after a small number of individuals colonize a new area

gene flow

the movement of genes into or out of a population due to interbreeding

petrification

Occurs when the organism's tissues are completely replaced by minerals.

imprints

impressions left by an organism (e.g. footprints)

molds

hollow spaces in rocks as the organisms within decay

casts

formed by minerals deposited in molds

homologous structures

structures that have the same basic anatomical features and evolutionary origins; origins and features are similar even if functions may not be

analogous structures

structures that have similar functions but may have different evolutionary origins and patterns of development

gastrula

a multilayered embryo; its structure suggests a common ancestry with other organisms

vestigial structure

remnants of an organ or structure that functioned in an earlier ancestor but currently has no known or important function

intraspecific competition

competition between members of the same species

reproductive isolation

isolation that is not geographical in nature and the members of two populations cannot interbreed and produce fertile offspring

heterotroph

An organism that cannot make its own food and gets food by consuming other living things and macromolecules

autotroph

An organism that makes its own food

coacervate droplets

clusters of colloidal molecules surrounded by a shell of water; tend to absorb and incorporate substances from the surrounding environment; possible predecessors of cells

biochemical pathways

A series of chemical reactions that occur in a specific order to carry out a life function

reducing, oxidizing

the addition of molecular oxygen to the atmosphere converted the atmosphere from a _____ one to an _____ one