Evolutionary Concepts

• Adaptation is an inherited trait that enhances survival and reproduction in a specific environment.
• Alleles are different versions of a gene.
• Analogous structures are features in different species that are similar in function and appearance but do not share a common ancestral origin.
• The Andes Mountains are a significant geographical feature.
• Artificial selection is the process by which humans breed animals and plants for particular traits.
• The Beagle was the ship on which Charles Darwin made his voyage.
• Biogeography is the study of the geographic distribution of species.
• The bottleneck effect is a sharp reduction in the size of a population due to environmental events or human activities.
• Class is a taxonomic rank in the classification of organisms.
• Common ancestry is the concept that all life shares a single ancestor.
• Convergent evolution is the independent evolution of similar features in different lineages.
• Directional selection is a mode of natural selection in which a single phenotype is favored, causing the allele frequency to continuously shift in one direction.
• Disruptive selection is a mode of natural selection in which extreme values for a trait are favored over intermediate values.
• Divergent evolution is the accumulation of differences between groups which can lead to the formation of new species.
• Diversification is the process by which new species arise and increase the taxonomic diversity.
• Diversifying selection favors multiple extreme phenotypes, leading to increased variation.
• Fitness is the ability of an organism to survive and reproduce in its environment.
• The founder effect occurs when a small group establishes a new population.
• Gene flow is the transfer of genetic variation from one population to another.
• A gene pool is the set of all genes, or genetic information, in any population, usually of a particular species.
• Genetic drift is the change in the frequency of an existing gene variant in the population due to random chance.
• Hardy-Weinberg equilibrium describes the conditions under which allele and genotype frequencies in a population will remain constant from generation to generation.
• Heritable traits can be passed down from one generation to the next.
• Homologous structures are similar in related organisms because they were inherited from a common ancestor.
• Homology is similarity due to shared ancestry
• Intermediate type references fossils or extant species that exhibit a mix of traits from different groups.
• Lamarck proposed that life evolves, with species changing over time.
• Charles Lyell influenced Darwin with his geological findings, suggesting that Earth is very old and constantly changing.
• Macroevolution refers to evolutionary changes that occur at or above the level of species
• Microevolution is the change in allele frequencies that occur over time within a population.
• Migration is the movement of organisms from one place to another.
• Modern synthesis is the modern theory of evolution that combines Mendelian genetics with Darwinian evolution.
• A molecular clock uses mutation rates in DNA to estimate the time of divergence between species.
• Morphology is the study of the form and structure of organisms and their specific structural features.
• Mutation is the ultimate source of genetic variation.
• Natural selection is the differential survival and reproduction of individuals due to differences in phenotype.
• Order is a taxonomic rank used in the classification of organisms.
• Paleontology is the study of prehistoric life.
• The Paleozoic era is the earliest of three geologic eras of the Phanerozoic Eon.
• Pangaea was a supercontinent that existed during the late Paleozoic and early Mesozoic eras.
• Phylum is a taxonomic rank in the classification of organisms.
• A population is a group of individuals of the same species living in the same area.
• Punctuated evolution suggests that species evolve during short periods of rapid change.
• Random fertilization is the random nature of fertilization.
• Sexual dimorphism is the condition where the two sexes of the same species exhibit different characteristics beyond the differences in their sexual organs.
• Sexual selection is the process in which individuals with certain inherited traits are more likely than other individuals to obtain mates.
• A species is a group of living organisms consisting of similar individuals capable of exchanging genes or interbreeding.
• Stabilizing selection favors intermediate variants and reduces variation.
• Vestigial structures are anatomical features that no longer seem to have a purpose in the current form of an organism of the given species.

Natural Selection

• Natural selection requires variation, inheritance, differential survival, and reproduction.

Charles Darwin

• Darwin's voyage on the Beagle and observations in the Galapagos shaped his theory of evolution.

Jean-Baptiste Lamarck

• Lamark proposed inheritance of acquired characteristics which influenced Darwin's evolutionary thought.

Charles Lyell

• Lyell's work on geology influenced Darwin by suggesting Earth is old and constantly changing.

Alfred Russel Wallace

• Wallace independently developed a theory of evolution by natural selection.

Darwin's Voyage on the Beagle

• On his voyage, Darwin observed diverse species and collected evidence that influenced his later theories.

Modern Synthesis

• Modern synthesis integrates genetics with natural selection, which gives a comprehensive view of evolution.

Adaptation vs. Change/Trait

• Adaptation enhances survival and reproduction, while change/trait may or may not have a specific function.

Artificial Selection vs. Natural Selection

• Artificial selection is driven by human choice, while natural selection is driven by environmental factors.

Hardy-Weinberg Equilibrium

• Hardy-Weinberg equilibrium calculates allele and genotype frequencies under specific conditions.
• Variables in the Hardy-Weinberg equation include p, q, p^2, q^2, and 2pq.

Natural Selection Forces

• Forces of natural selection include variation, inheritance, differential survival, and reproduction.

Genetic Drift

• Genetic drift is influenced by population size and can be prevented by gene flow.

Gene Flow

• Gene flow happens through migration and interbreeding between populations.

Mutations

• Mutations provide the raw material for evolutionary change.

Common Descent

• The theory of common descent states that all living organisms share a single common ancestor.

Fossil Formation

• Fossils form under specific conditions like rapid burial and hard part preservation.

Smallest Unit of Evolution

• The smallest unit of evolution is a population.

Change vs. Adaptation

• A change/trait may be random, while an adaptation provides a survival advantage.

Genetic Variation

• Genetic variation comes from mutation, gene flow, and sexual reproduction.

Microevolution vs. Macroevolution

• Microevolution involves changes within a species, while macroevolution involves changes above the species level.

Fossils in Darwin's Theory

• Fossils provided evidence of extinct species and transitional forms for Darwin.

Darwin and Malthus

• Darwin used Malthus' ideas on population growth to explain competition and survival.

Survival of the Fittest

• Survival of the fittest means the most reproductively successful survive.

Types of Selection

• Directional selection shifts the average trait value.
• Disruptive selection favors extreme trait values.

Founder Effect

• The founder effect results in a loss of genetic variation within a new population.

Bottleneck Effect

• The bottleneck effect can drastically alter traits by chance.

Fossil Formation Requirements

• Fossil formation requires specific conditions for preservation.

Fossil Age Estimation

• Fossil ages can be estimated using radiometric dating.

Homologous vs. Analogous Structures

• Homologous structures indicate common ancestry, while analogous structures indicate convergent evolution.

Molecular Clock

• The molecular clock estimates divergence times.

DNA Similarities

• DNA similarities reflect evolutionary relationships.

Convergent vs. Divergent Evolution

• Convergent evolution leads to similar traits, while divergent evolution leads to different traits.

Key Dates

• Key dates include the age of the oldest known fossils and the age of Earth.

Embryology

• Embryology reveals common ancestry through conserved developmental patterns.

Amino Acid Sequences

• Amino acid sequences in different organisms reflect how related they are.