Introduction to Darwinian Evolution - Vocabulary Flashcards

A set of vocabulary flashcards covering key terms from the Darwinian evolution lecture notes.

Evolution

Accumulation of inherited changes within populations over time.

Population

Group of individuals of one species that live in the same geographic area at the same time.

Species

Group of organisms with similar structure, function, and behavior capable of interbreeding.

Telos (Aristotle)

Aristotle's idea of natural affinities or purpose guiding organisms.

Lamarck

Early theory proposing that organisms change through natural phenomena; later discredited after Mendel’s genetics.

Beagle voyage

Darwin's 1831 voyage on HMS Beagle that provided observations leading to the theory of evolution.

Galápagos Islands

Islands where Darwin observed variations among species that influenced his thinking.

Lyell

Geologist whose Principles of Geology promoted uniformitarianism and influenced Darwin.

Artificial selection

Breeders selecting traits to develop domesticated varieties (e.g., kale from wild cabbage).

Malthus

Thomas Malthus; argued populations grow geometrically while resources grow arithmetically, causing competition.

Natural selection

Evolution by differential survival and reproduction due to inherited variation; favorable traits persist.

Adaptation

Inherited traits that improve survival or reproduction in a given environment.

Overproduction

Each species tends to produce more individuals than can survive to maturity.

Variation

Individuals in a population differ in characteristics.

Selection

Some individuals survive longer and reproduce more than others.

Biological fitness

Ability of an organism to survive and reproduce, passing on its genes.

Four observations of natural selection

1) Genetic variation exists; 2) populations tend to increase; 3) competition for resources; 4) offspring with favorable traits survive.

Synthetic theory of evolution

1930s–1940s synthesis of Mendelian inheritance with natural selection; mutation provides variability.

Fossils

Remains or traces of past organisms preserved in rocks; evidence of evolution.

Fossil record

Direct evidence of evolution from fossils showing the progression of life through time.

Homologous structures

Structures in related species derived from a common ancestor.

Vestigial structures

Remnants of features that served a function in ancestors, indicating past adaptation.

Homoplasy (convergent evolution)

Similar traits in distantly related organisms due to similar selective pressures.

Convergent evolution

Independent evolution of similar traits in unrelated lineages due to similar environments.

Comparative anatomy

Study of structural similarities and differences among organisms.

Phylogeny

Evolutionary history of a group of related species.

Phylogenetic tree

Diagram showing lines of descent among related species based on molecular data.

Biogeography

Study of past and present geographic distribution of organisms; continental drift has shaped evolution.

Continental drift

Movement of Earth's continents; a major factor in evolutionary patterns.

Pangaea

Ancient supercontinent whose breakup illustrates continental drift.

Recombination (crossing over)

Crossing over during meiosis increases genetic variation among offspring.

Mutation

Change in DNA sequence introducing new genetic variation; can affect protein structure and phenotype.

Gene duplication

Creation of gene families within a genome; produces orthologs and paralogs.

Orthologous genes

Found in different species; derived from a common ancestral gene after speciation.

Paralogous genes

Found within a species; duplicated genes that may diverge in function.

Gene flow

Movement of individuals and alleles into or out of populations; reduces differences between populations.

Genetic drift

Random fluctuations in allele frequencies in small populations; includes founder and bottleneck effects.

Founder effect

Small group becomes isolated from a larger population, altering allele frequencies.

Bottleneck effect

Sharp reduction in population size that decreases genetic diversity and alters allele frequencies.

Punctuated equilibrium

Long periods of little evolutionary change interrupted by brief bursts of rapid change.

Gradualism

Slow, continuous accumulation of changes over time leading to new species.

Common ancestor

An ancestral species from which two or more lineages descend.

Molecular evidence

DNA and protein data that reveal evolutionary relationships and history.

Radiometric dating

Dating fossils by measuring decay of radioisotopes to determine age.

Mechanisms of evolutionary change

Natural selection, genetic drift, gene flow, mutation, and recombination.