AP Bio - Evolution Vocab

Plato

An ancient Greek philosopher (427-327 BC); evolution is counterproductive since world is made of ideal organisms perfectly adapted to their environment.

Aristotle

Ancient Greek philosopher (384-322 BC); species arranged in a “fixed scale of natural perfection” —each organism placed on a rung of ladder of complexity.

Linnaeus

Created classification system called taxonomy and binomial nomenclature; God creates, Linnaeus arranges hierarchy of animal kingdom by species evolved from common ancestors.

Cuvier

French Zoologist (1825): Theory of Catastrophism - natural history has been punctuated by periodic catastrophic events causing mass extinctions, which are repopulated by immigrating species and rock deposits. He developed paleontology but rejected evolution, labeled gaps in fossil succession as mass extinction events, used Darwin’s theory of natural selection + survival of the fittest.

Hutton

(1795): Principle of Gradualism - geological changes occur slowly over time, leading to significant changes in the Earth's features and supporting the idea of evolution.

Lyell

(1830): Theory of Uniformitarianism - geological processes that alter the Earth are uniform through time; slow, subtle processes working for long time cause major change → Earth is OLD!

Malthus

British Economist: (1798) Principle of Population - Observed that the human race would be likely to overproduce if the population size was not controlled (via disease, famine, war, calamity) overproduction leads to struggle for existence and ultimately influences natural selection and evolution.

Lamarck

(1809): Organisms evolve to greater complexity and perfection—petter adaptation to environment, “use and disuse”—parts used for survival grow bigger and stronger, parts not used deteriorate, "inheritance of acquired characteristics”—modifications are passed onto offspring.

Wallace

British Naturalist (1855): Theory of Evolution - Co-developed theory of natural selection with Darwin—helpful traits increase survival and reproduction rates so following generations will carry them.

Mendel

Australian monk (1822): “the father of genetics” is known for his ground breaking experiments with pea plants revealing the basic principles of heredity, including concepts of dominant and recessive traits, laws of segregation and independent assortment.

Descent with Modification

The idea that species change over time, give rise to new species and share a common ancestor - evolutionary tree

Natural Selection

The process that drives evolution. Differential success in reproduction results in adaptation of organisms to environment over long periods of time.

Artificial Selection

• breeding of domesticated plants and animals for desired traits

• shows huge changes in populations over short time

Biogeography

• geographical distribution of species

• different geographic regions, different mammalian “brands”

Convergent Evolution

Organisms that appear similar and related due to similar environments but have evolved independently from separate ancestors

Comparative Anatomy

The study of similarities and differences in the anatomy of different species—using homologous structures and vestigial organs as evidence of evolution

Homologous Structures

anatomical signs of descent with modification—the basic similarity of forelimbs is a consequence of descent of all mammals from a common ancestry

Vestigial Organs

rudimentary homologous structures with marginal or no functions—snakes with pelvis + leg bones, Humans with tail bones + excess body hair

Gene Pool

a population’s genetic makeup; all of the different alleles in all of the individuals in a population

Hardy-Weinberg Theorem

• describes the gene pool of non-evolving population

• allele frequencies will remain constant over generations unless acted upon by agents other than Mendelian segregation and recombination of alleles

• we can compare this non-evolving population with another to see if evolution is happening

• Equation for next generation = p² + 2pq + q² = 1

Microevolution

change in allele frequencies in a population over generations

Genetic Drift

unpredictable changes in allele frequencies due to chance events when populations are small

the smaller the sample, more chance of deviation from one generation to the next → can lead to a loss of genetic variation and loss of alleles due to death or lack of reproduction

Bottleneck Effect

number of individuals in a large population is drastically reduced by a sudden change in the environment

Founder Effect

new population started by few individuals that do not represent the gene pool of the larger source population

Gene Flow

• genetic exchange due to migration of fertile individuals or gametes between populations → increases frequency of particular alleles in next generation

• reduce differences between populations

Polymorphism

Heterozygote Protection

when a heterozygote is protected against a certain disease or condition, even though they carry a potentially harmful allele

Heterozygote Advantage

• Individuals heterozygous at a particular locus have greater survivorship and reproductive success than homozygotes

• multiple alleles maintained at locus by natural selection

• promotes balanced polymorphism

Directional Selection

• shifts frequency curve for a phenotypic character in one direction by favoring what used to be rare individuals

• common during periods of environmental change or when members of a population migrate to a new habitat with different environmental conditions

Disruptive Selection

environmental conditions favor individuals at both extremes of phenotypic range over intermediate phenotypes

Stabilizing Selection

• favors intermediate variants and acts agains extreme phenotypes

• reduces variation and maintains predominant phenotypes

Sexual Selection

individuals with certain inherited characteristics that are more likely to obtain mates

Biological Species Concept

Defines a species as groups of interbreeding populations that are reproductively isolated from other groups and produce fertile and viable offspring

Allopatric Speciation

new population forms geographically apart from parent population

Sympatric Speciation

new species forms within geographically overlapping populations

Adaptive Radiation

rapid diversification of a single ancestral species—each species is adapted to their respective ecological niches

Polyploidy

when an organism has an extra set of chromosomes

Autopolyploidy

>2n from a single species

Allopolyploidy

>2n from two different species, two different species produce sterile hybrids, self propagate, and become a fertile polyploid generations later

Gradualism

big changes occur by accumulation of many small ones—species diverge slowly and gradually

Punctuated Equilibrium

species diverge in spurts of relatively rapid change

Macroevolution

origin of new taxonomic groups

Protobionts

AKA protocells are hypothetical precursors to cells—collections of lipids or other organic molecules that could have existed before true cells

Sedimentation

Layers of minerals deposited in intervals in which organisms settle and are preserved

Relative Dating

compare ages of fossils based on younger sediments superimposed on older ones

Absolute Dating

age given in years

Radiometric Dating

measuring radioactive isotopes in fossils

Half Live

number of years it takes for half of the original sample to decay

Heterochrony

change in the timing or rate of developmental timing in an organism compared to its ancestors—alterations in size and shape

Paedomorphosis

when adult organisms retain juvenile or larval traits of their ancestors

Homeotic (Hox) Genes

regulator genes that control the pattern or body formation during embryonic development

Systematics

the study of diversity and evolutionary relationships of organisms over time and the identification and classification of organisms—involves both phylogeny and taxonomy

Phylogenetics

the study of evolutionary development of a group of organisms → relationships are depicted in a tree diagram showing the closeness in taxon relation between species

Taxonomy

the identification, naming, description, and classification of organisms

Taxon

biologically classified group of related organisms - KPCOFGS

Endosymbiosis

describes a relationship where one species lives inside of the other

Cladogram

diagram that depicts the relationship between different groups of taxa called “clades” based on shared or derived characteristics

Analogous Structures

features of a different species that are similar in function but not necessarily in structure which are not derived from a common ancestor