AP Biology Evolution Vocab

Miller-Urey Experiment

Used a simple apparatus containing inorganic molecules and an electrode, and formed amino acids

The RNA World Hypothesis

proposes that RNA was the earliest genetic material

Evolution

The change in genetic makeup of a population over time

Paradigm Shifts

A fundamental change in approach or underlying assumptions

Charles Darwin

Theory of evolution by natural selection

Natural Selection, Postulate #1

There is variation inthe population

Adaptations

Heritable characteristics that enhance an organism's ability to survive and reproduce in specific environments

Natural Selection, Postulate #2

More young are produced than can survive

Natural Selection, Postulate #3:

Different survival and reproduction

Fitness

Fitness is measured by reproductive success, not lifespan

Natural Selection, Postulate #4

Populations change over time

Phenotype

The physical expression of a gene

Genotype

The genetic combination of alleles for a trait

Selective Pressures

Any Biotic or Abiotic factors in the environment that make some variation more favorable than others.

Environmental Stability

As the environment changes, so do selection pressures

Directional Selection

Favors one extreme or the other, so frequency shifts towards one extreme or another

Disruptive Selection

Favors both extremes in the population, resulting in higher frequencies of fewer of the intermediates.

Stabilizing selection

Favors the intermediate and decreases the frequencies of individuals with extreme phenotypes

Comparative Morphology

Study of form/structure for similarities resulting from common ancestry

Homologous Structure

Atomical structures that have been adapted to different environments/functions but have the same underlying structure

Vestigial Structures

Remnants of structures that served a purpose in an ancestor but have limited/no function now

Relative Dating

Uses the age of the rocks

Radiometric Dating

Uses the decay of radioactive isotopes

Biogeography

Geographical location of extant species and fossils

Artificial Selection

The process by which humans select for traits, driving organisms to evolve

Variation

The different combinations of alleles and phenotypes found in a population

Alleles

Alternate forms of a gene

Heterozygote Advantage

A heterozygote genotype has a higher relative fitness than either a Homozygous dominant or a homozygous recessive

Gene Pool

All alleles present in a breeding population

Genetic Drift

A change in allele frequencies

Bottleneck Effect

A type of genetic drift that occurs when a population size is reduced to a small number of individuals

Founder Effect

A type of genetic drift that occurs when a population is separated from other members of the population

Gene Flow

Addition or removal of genes from a population

Hardy-Weinberg Conditions

No natural selection, no mutations, no gene flow, population must be large, random mating

Hardy Weinberg Equations

Taxonomy

Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species

Taxonomy memory aid

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Taxonomy

Division of eukaryotes into categories based on similarities and differences

Speciation

The process by which new species arise

Divergent Evolution

Groups from the same common ancestor accumulate differences, resulting in the formation of a new species

Reproductive Isolation

Biological barriers prevent members of two different species from producing viable, fertile offspring

Prezygotic Mechanisms

Prevent the zygote from being formed

Postzygotic Mechanisms

Prevent the zygote from becoming a viable, fertile adult

Geographic Isolation:

Populations are not physically in the same location

Behavioral Isolation

Do not have the same mating rituals/songs/food source

Temporal isolation

Different mating seasons

Mechanical isolation

Anatomy is not compatible for mating

Gametic Isolation

Sperm and egg cannot fuse

Reduced Hybrid Viability

Offspring born but not healthy enough to survive adulthood

Reduced Hybrid Fertility

Offspring born, healthy enough to survive to adulthood, but sterile

Allopatric Speciation

Occurs when populations are geographically isolated

Sympatric Speciation

Occurs in populations with geographical overlap

Adaptive Radiation

Many species arise from one common ancestor, each filling its own niche

Gradualism

Species descend from a common ancestor and gradually diverge at a steady rate over long periods of time

Punctuated Equilibrium:

Long periods of stasis punctuated by bursts of rapid change

Analogous Structures:

Structures that have the same function but are different in underlying structure

Phylogenetic Trees

Show hypothetical evolutionary relationships