(Natural selection, increases frequency of, heritable traits that improve survival or reproduction)
(Natural selection, acts on, phenotypic variation in populations)
(Phenotypic variation, arises from, genetic variation and environmental effects)
(Genetic variation, is produced by, mutation, recombination, and gene flow)
(Mutation, introduces, new alleles)
(Recombination, reshuffles, existing alleles into new combinations)
(Gene flow, transfers, alleles between populations)
(Genetic drift, changes frequency of, alleles by random sampling)
(Genetic drift, has strongest effect in, small populations)
(Effective population size, determines, strength of genetic drift)
(Founder effect, is a form of, bottleneck that alters allele frequencies in a new population)
(Bottleneck, reduces, genetic diversity)
(Selection coefficient, measures, fitness difference between genotypes)
(Fitness, is the expected reproductive contribution of, an individual or genotype to future generations)
(Relative fitness, determines, direction and strength of selection)
(Directional selection, favors, one extreme phenotype)
(Stabilizing selection, favors, intermediate phenotypes)
( disruptive selection, favors, both extreme phenotypes)
(Sexual selection, favors, traits that increase mating success)
(Sexual selection, can lead to, sexual dimorphism)
(Sexual dimorphism, is difference in, morphology or behavior between sexes)
(Kin selection, favors, traits that increase inclusive fitness)
(Inclusive fitness, sums, an individual's direct fitness and the fitness effects on relatives weighted by relatedness)
(Altruism, can evolve through, kin selection or reciprocal interactions)
(Reciprocal altruism, evolves when, individuals exchange benefits over time)
(Group selection, is selection acting at, the level of groups rather than individuals; it is usually weaker than individual-level selection)
(Multilevel selection, considers, selection operating at genes, individuals, and groups)
(Mutation types, include, point mutations, insertions, deletions, duplications, inversions, and translocations)
(Gene duplication, provides, raw material for evolution of new functions)
(Neofunctionalization, occurs when, a duplicated gene acquires a new function)
(Subfunctionalization, occurs when, duplicated genes divide ancestral functions)
(Pseudogene, is a, nonfunctional copy of a gene)
(Horizontal (lateral) gene transfer, moves, genetic material between unrelated organisms)
(Horizontal gene transfer, is common in, bacteria and archaea)
(Endosymbiosis, gave rise to, mitochondria and chloroplasts in eukaryotes)
(Common descent, states that, all life shares ancestry)
(Tree of life, represents, evolutionary relationships among organisms)
(Phylogeny, reconstructs, relationships using morphological and molecular data)
(Homology, indicates, similarity due to shared ancestry)
(Analogy (homoplasy), indicates, similarity due to, convergent or parallel evolution rather than common ancestry)
(Convergent evolution, produces, similar traits in unrelated lineages due to similar selection pressures)
(Parallel evolution, produces, similar traits in related lineages with similar developmental pathways)
(Speciation, is the process by which, one lineage splits into two or more reproductively isolated lineages)
(Reproductive isolation, can be caused by, prezygotic or postzygotic barriers)
(Prezygotic barriers, include, temporal, behavioral, ecological, mechanical, and gametic isolation)
(Postzygotic barriers, include, hybrid inviability and hybrid sterility)
(Allopatric speciation, occurs when, geographic isolation separates populations)
(Sympatric speciation, can occur via, ecological specialization, polyploidy, or sexual selection within the same area)
(Peripatric speciation, is a form of, allopatric speciation with a small founder population)
(Parapatric speciation, occurs with, neighboring populations experiencing different selection and limited gene flow)
(Polyploidy, instantly creates, reproductive isolation in many plants)
(Adaptive radiation, is rapid diversification when, many ecological niches become available)
(Macroevolution, studies, large-scale evolutionary patterns above the species level)
(Microevolution, studies, allele frequency change within populations)
(Mod ern synthesis, integrated, Darwinian selection with Mendelian genetics and population genetics in the 20th century)
(Darwin and Wallace, proposed, natural selection as a mechanism of adaptation)
(Fisher, Haldane, and Wright, developed, population genetics foundations)
(Fisher, introduced, fundamental theorem of natural selection and quantitative genetics concepts)
(Sewall Wright, introduced, adaptive landscape and importance of drift and population structure)
(Haldane, contributed, mathematical models of selection and mutation)
(Neutral theory (Kimura), proposes that, most molecular variation is due to genetic drift of neutral mutations)
(Neutral mutations, have, no effect on fitness)
(Molecular clock, assumes, roughly constant mutation rate for neutral substitutions over time)
(Molecular evolution, is studied using, DNA, RNA, and protein sequence comparisons)
(Comparative genomics, reveals, conserved genes and regulatory elements across taxa)
(Orthologs, are genes in different species that, descended from a single gene in the last common ancestor)
(Paralogs, are genes related by, duplication within a genome)
(Phylogenetic inference, uses, parsimony, maximum likelihood, and Bayesian methods)
(Selection scans, identify, genomic regions under recent positive selection)
(Selective sweep, reduces, genetic variation near a beneficial allele)
(Genetic hitchhiking, increases frequency of, linked neutral alleles when selection acts on a nearby allele)
(Background selection, reduces, neutral genetic diversity linked to deleterious alleles)
(Muller's ratchet, causes, accumulation of deleterious mutations in small asexual populations)
(Compensatory evolution, fixes, deleterious effects by subsequent mutations)
(Pleiotropy, occurs when, a single gene affects multiple traits)
(Epistasis, occurs when, effects of alleles at one gene depend on alleles at other genes)
(Developmental constraints, limit, the range of phenotypic variation available to selection)
(Evo-devo (evolutionary developmental biology), studies, how changes in development drive morphological evolution)
(Regulatory evolution, often alters, gene expression patterns rather than protein sequences)
(Hox genes, control, body plan patterning in animals)
(Changes in cis-regulatory elements, can produce, morphological differences with fewer pleiotropic effects)
(Phenotypic plasticity, allows, a genotype to produce different phenotypes in different environments)
(Reaction norm, describes, range of phenotypes produced by a genotype across environments)
(Plasticity-first hypothesis, proposes that, plastic responses can precede and facilitate genetic evolution)
(Sexual reproduction, generates, new genotypic combinations via recombination and independent assortment)
(Clonal reproduction, produces, genetically identical offspring)
(Asexual reproduction, limits, genetic variation except by mutation)
(Artificial selection, demonstrates, selection can produce, major phenotypic changes over short timescales)
(Domestication, is an example of, human-driven evolution)
(Antibiotic resistance, evolves by, selection on genetic variants conferring resistance)
(Viral evolution, can occur rapidly because of, high mutation rates and large population sizes)
(Lenski long-term E. coli experiment, documents, real-time adaptation, fitness changes, and rare innovations over tens of thousands of generations)
(Peppered moth example, illustrated, industrial melanism and selection on camouflage; its history involved complexity and controversy)
(Darwin's finches, illustrate, adaptive changes in beak morphology due to, ecological selection pressures)
(Transitional fossils, provide, evidence of intermediate forms in major evolutionary transitions)
(Fossil record, documents, patterns of, descent with modification, including radiations and extinctions)
(Extinction, is, a common fate for species and driver of macroevolutionary change)
(Mass extinctions, can create, ecological opportunities for adaptive radiations)
(Biogeography, studies, geographical distribution of species shaped by dispersal, vicariance, and continental drift)
(Plate tectonics, explains, historical distribution patterns and vicariant speciation)
(Comparative anatomy, identifies, homologous structures across species)
(Vestigial structures, are, reduced or nonfunctional anatomical features inherited from ancestors)
(Embryology, reveals, conserved early developmental patterns across related taxa)
(Morphological convergence, can mislead, phylogenetic inference if not accounted for)
(Molecular phylogenies, often clarify, relationships obscured by morphological convergence)
(Hybridization, can result in, gene exchange between species and formation of hybrid species)
(Introgression, is transfer of, alleles from one species into another via hybridization)
(Genomic islands of divergence, are regions, resistant to gene flow during speciation with gene flow)
(Adaptive introgression, spreads, beneficial alleles across species boundaries)
(Selection-mutation balance, maintains, deleterious allele frequencies at equilibrium determined by mutation rate and selection strength)
(Mutation rate, varies among, organisms, genomic regions, and types of sequences)
(Repair mechanisms, reduce, mutation rates via DNA repair pathways)
(Transposable elements, can, move within genomes and create genetic variation)
(Genome size, does not correlate simply with, organismal complexity (C-value paradox))
(Coevolution, occurs when, interacting species reciprocally influence each other's evolution)
(Predator-prey coevolution, can drive, arms races in defense and offense traits)
(Mutualistic coevolution, can lead to, tight adaptations between partners)
(Virulence evolution, involves, trade-offs between, transmission and host harm)
(Trade-offs, constrain evolution because, improvements in one trait can reduce performance in another)
(Adaptive landscape, visualizes, fitness of genotypes or phenotypes across trait space)
(Evolutionary stable strategy (ESS), is a strategy that, cannot be invaded by rare alternative strategies)
(Game theory, models, frequency-dependent selection and social interactions)
(Frequency-dependent selection, changes, fitness of phenotypes depending on their frequency)
(Positive frequency-dependent selection, favors, common phenotypes)
(Negative frequency-dependent selection, favors, rare phenotypes)
(Clines, are gradients, in trait or allele frequencies across geographic space)
(Quantitative genetics, studies, inheritance of continuous traits using additive genetic variance)
(Breeder's equation, predicts, response to selection = heritability × selection differential)
(Heritability (narrow-sense), is proportion of, phenotypic variance due to additive genetic variance)
(GxE interaction, occurs when, genotype effects depend on environment)
(Polygenic traits, are influenced by, many genes each of small effect)
(Genome-wide association studies (GWAS), associate, genetic variants with phenotypic traits)
(Selection on standing genetic variation, can produce, rapid evolutionary responses)
(De novo mutation, can provide, new beneficial alleles for adaptation)
(Standing variation, can allow, soft selective sweeps where multiple alleles rise in frequency)
(Hard sweep, originates from, a single new beneficial mutation that goes to fixation)
(Phylogeography, combines, phylogenetics and geographic distribution to infer history of lineages)
(Molecular signatures of selection, include, high dN/dS, reduced diversity, extended haplotype homozygosity)
(dN/dS ratio, compares, nonsynonymous to synonymous substitution rates to infer selection)
(Positive selection, increases, fixation of advantageous nonsynonymous substitutions)
(Purifying selection, removes, deleterious mutations and maintains conserved sequences)
(Conserved elements, indicate, functional constraints over evolutionary time)
(Comparative transcriptomics, reveals, differences in, gene expression evolution across species)
(Epigenetic inheritance, can transmit, environmentally induced states across generations in some cases)
(Cultural evolution, transmits, behaviors and knowledge via social learning and can interact with genetic evolution)
(Gene-culture coevolution, describes, feedbacks between, cultural practices and genetic evolution (e.g., lactase persistence))
(Microbiome evolution, influences, host phenotype and can evolve in association with hosts)
(Major transitions in evolution, include, origin of life, eukaryotes, multicellularity, and social groups)
(Multicellularity, evolved multiple times, independently in different lineages)
(Sexual reproduction, may evolve and be maintained due to, benefits of recombination in changing environments)
(Adaptive peak shifts, may require, genetic drift or high mutation input to cross valleys)
(Punctuated equilibrium, proposes that, species remain stable for long periods punctuated by rapid change)
(Gradualism, proposes that, evolutionary change is slow and continuous)
(Evolutionary theory, accommodates, both punctuated patterns and gradual change depending on context)
(Selection experiments, provide, controlled tests of evolutionary hypotheses)
(Experimental evolution, allows, direct observation of adaptation, parallelism, and constraint)
(Parallel evolution in experiments, indicates, repeatability of selection under similar conditions)
(Repeatability, of evolution depends on, genetic variation, constraints, and contingency)
(Contingency, implies, historical events can alter evolutionary outcomes)
(Historical contingency, documented in, replay-of-life thought experiments and some empirical studies)
(Macroevolutionary patterns, include, trends, stasis, radiations, and convergences)
(Key innovations, can trigger, increased diversification rates)
(Rate of evolution, varies, among lineages, traits, and time)
(Phylogenetic comparative methods, account for, shared ancestry when comparing species)
(Ancestral state reconstruction, infers, traits of common ancestors using phylogenies)
(Neutral networks, allow, genotypes with similar phenotypes to, drift and explore sequence space)
(Robustness, is, resistance of phenotype to genetic or environmental perturbation)
(Evolvability, is, capacity of a system to generate adaptive variation)
(Selection on evolvability, can be indirect, acting on mechanisms that produce variation)
(Adaptive landscape ruggedness, influences, predictability and paths of evolution)
(Genome architecture, affects, recombination rates, linkage, and evolution of complex traits)
(Linkage disequilibrium, measures, nonrandom association of alleles at different loci)
(Recombination rate variation, shapes, patterns of linked selection and genetic diversity)
(Meta-population dynamics, influence, local adaptation, extinction–colonization balance, and gene flow)
(Source-sink dynamics, describe, populations supported by immigrants from productive habitats)
(Cladogenesis, is lineage splitting producing, phylogenetic branching)
(Anagenesis, is evolutionary change within, a single lineage without branching)
(Molecular adaptation, can involve, structural protein changes or regulatory changes)
(Protein evolution, is constrained by, stability, folding, and functional interactions)
(Trade-offs between robustness and adaptability, can shape, evolutionary trajectories)
(Phylogenomic data, can resolve, deep evolutionary relationships when carefully modeled)
(Long-branch attraction, is a phylogenetic artifact caused by, unequal rates and poor models)
(Model choice in phylogenetics, affects, accuracy of inferred trees)
(Hierarchical organization of life, means, selection can act at gene, cell, organism, and group levels)
(Selfish genetic elements, propagate, even if neutral or harmful to organismal fitness)
(Meiotic drive, biases, transmission of certain alleles and can influence evolution)
(Cancer, is evolution within, somatic cell populations under selection)
(Clonal interference, occurs in, large asexual populations when multiple beneficial mutations
