Biology Evolution

Evolution

Change over time that makes descendant populations different from ancestors

Microevolution

Small-scale evolutionary change affecting one population

Macroevolution

Large-scale evolutionary change affecting multiple populations

Natural selection

Process where individuals with beneficial traits survive and reproduce more

Overproduction of offspring

More offspring are produced than can survive

Variation

Differences among individuals in a population

Adaptation

Inherited trait that improves survival or reproduction

Descent with modification

Over time advantageous traits become more common in a population

Genetic drift

Random change in allele frequencies due to chance

Gene flow

Movement of genes between populations

Sexual selection

Selection based on success in attracting mates

Mutation

Random change in DNA creating new variation

Directional selection

Selection favoring one extreme phenotype

Stabilizing selection

Selection favoring the average phenotype

Disruptive selection

Selection favoring both extreme phenotypes

Gradualism

Evolution occurring slowly and continuously over long periods

Punctuated equilibrium

Long periods of little change interrupted by rapid evolution

Convergent evolution

Unrelated species evolve similar traits due to similar environments

Divergent evolution

Related species become increasingly different over time

Speciation

Formation of new species

Extinction

Permanent disappearance of a species

Coevolution

Two species evolve in response to each other

Hardy-Weinberg equilibrium

Condition where allele frequencies remain constant in a population

Allele frequency

How common an allele is in a population

Genotype frequency

How common a genotype is in a population

p

Frequency of the dominant allele in Hardy-Weinberg equations

q

Frequency of the recessive allele in Hardy-Weinberg equations

p²

Frequency of homozygous dominant genotype

2pq

Frequency of heterozygous genotype

q²

Frequency of homozygous recessive genotype

Homologous structures

Structures with similar anatomy due to common ancestry

Analogous structures

Structures with similar function but different evolutionary origins

Vestigial structures

Reduced structures with little or no current function inherited from ancestors

Morphology

Study of organism structure and anatomy

Biogeography

Study of geographic distribution of species

Biochemistry

Study of chemical similarities such as DNA and proteins among organisms

Embryology

Study of embryos and development patterns

Paleontology

Study of fossils and ancient life

Fossil record

Collection of fossils showing evidence of past life and evolution

Common ancestor

An ancestral species shared by multiple descendants

Artificial selection

Humans selectively breed organisms for desired traits

Species

Group of organisms that can interbreed and produce fertile offspring

Hybrid

Offspring produced from two different species

Reproductive isolation

Barriers preventing species from interbreeding

Behavioral isolation

Species separated by differences in courtship or mating behaviors

Analogous evolution

Independent evolution of similar features in species of different ancestry

Phylogenetic tree

Diagram showing evolutionary relationships among species

Cladogram

Branching diagram showing evolutionary relationships based on shared traits

Node

Point on a cladogram representing a common ancestor

Outgroup

Species least closely related used for comparison in a cladogram

Maximum parsimony

Principle that the simplest evolutionary pathway is most likely

Derived trait

Newly evolved trait shared by descendants

Ancestral trait

Older trait inherited from distant ancestors

Mutation resistance

Beneficial mutation allowing survival against threats like antibiotics or pesticides

Antibiotic resistance

Ability of bacteria to survive antibiotic treatment

Selective pressure

Environmental factor influencing survival and reproduction

Fitness

Ability of an organism to survive and reproduce in its environment

Camouflage

Adaptation allowing organisms to blend into surroundings

Industrial melanism

Increase of dark-colored organisms due to environmental changes like pollution

Adaptive radiation

Rapid evolution of many species from a common ancestor

Continental drift

Movement of Earth’s continents over time affecting species distribution

DNA evidence

Genetic similarities used as evidence for evolution

Prokaryote

Simple single-celled organism lacking a nucleus

Marsupial

Mammal carrying young in a pouch

Prehensile tail

Tail adapted for grasping objects

Quills

Sharp protective spines found on some animals

Bipedal

Walking on two legs

Primates

Group of mammals including humans

Fertile offspring

Offspring capable of reproducing

Gene pool

All alleles present in a population

Environmental stimuli

Changes in surroundings affecting survival and evolution

Biological goals

Needs related to survival and reproduction

Analogous wings

Wings with similar function but different structures

Common ancestry

Shared evolutionary origin among organisms

Vestigial pelvis

Remnant pelvic bones in whales showing terrestrial ancestry

Mutation variation

Genetic differences created through mutations

Selection pressure

Force causing certain traits to be favored

Population evolution

Change in genetic makeup of a population over time

Survival of the fittest

Individuals best adapted to the environment reproduce more successfully

Divergence

Process of populations becoming increasingly different

Evolutionary theory

Scientific explanation for how populations change over time

List the 4 principles of natural selection.

Overproduction of offspring, variation, adaptation, and descent with modification

3 sources of genetic variation

Migration (gene flow), Mutations, Genetic Recombination in Meiosis

List the five conditions that must be true for evolution to NOT occur, making a population in genetic equilibrium.

Large population

No mutation

No migration

No natural selection

Random mating