The Nature of Science, Evidence of Evolution, and Natural Selection

Practice vocabulary flashcards covering the nature of science, scientific variables, lines of evolutionary evidence, speciation, and the mechanisms of natural selection.

Homologous Structures

Body structures across different species that share the same skeletal arrangement and ancestral origin but serve different functions, such as vertebrate forelimbs.

Vestigial Structures

Organs or body parts that have lost their original function through evolutionary change, such as pelvic bones in whales and the human third eyelid.

Embryological Development

Evidence for evolution demonstrating that the early developmental stages of different vertebrate embryos proceed in nearly identical ways.

Speciation

The evolutionary process by which a population splits and develops into distinct, reproductively isolated species that can produce fertile offspring.

Allopatric Speciation

Speciation that occurs when populations become separated by physical geographic barriers, such as islands, rivers, or canyons, preventing interbreeding.

Sympatric Speciation

Speciation occurring when populations live in the same geographic area but become reproductively isolated through behavioral or ecological shifts, such as apple maggot flies choosing different fruit hosts.

Phylogenetic Tree

A branching diagram illustrating how different biological species and clades are related through evolutionary history.

Monophyletic Group

A lineage grouping that includes a common ancestor and all of its descendants, such as tetrapod vertebrates.

Cladogram

A diagram used to depict evolutionary relationships among groups by identifying shared common characters and evolutionary milestones.

Convergent Evolution

The evolutionary pattern where distantly related organisms develop similar traits and adaptations independently due to shared environmental selection pressures.

Evolution

The change in the frequency of inherited traits within a biological population over time, functioning as the unifying theory of biology.

Frequency

The proportion or count of organisms in a population that possess a particular trait.

Natural Selection

Charles Darwin's evolutionary mechanism where individuals with traits best suited to their environment survive and produce more offspring ('survival of the fittest').

Adaptive Radiation

The diversification of an ancestral species into a variety of forms specialized for different ecological niches, illustrated by Galápagos finch beak variations.

Common Descent

The evolutionary concept that each modern living species has descended with modifications from pre-existing common ancestors over time.

Differential Survival

The principle of natural selection stating that individuals carrying advantageous traits survive longer and leave more progeny than individuals with less advantageous traits.

Artificial Selection

The process by which humans deliberately select and breed organisms with desirable phenotypic traits, such as breeding domesticated dogs.

Science

A systematic body of knowledge that investigates and explains the natural world based on testable evidence, excluding supernatural explanations.

Hypothesis

A testable and falsifiable explanation formulated to account for observed natural phenomena.

Experiment

A structured scientific investigation performed under controlled conditions to evaluate a specific hypothesis.

Manipulated (Independent) Variable

The experimental variable deliberately changed or manipulated by the researcher, represented on the X-axis.

Responding (Dependent) Variable

The variable measured or observed during an experiment to detect changes caused by the manipulated variable, represented on the Y-axis.

DRY MIX

A mnemonic device for graphing: Dependent variable = Responding variable = Y-axis; Manipulated variable = Independent variable = X-axis.

Quantitative Data

Scientific data recorded as measurable numbers, amounts, or numerical values.

Qualitative Data

Scientific data collected as descriptive attributes or qualities rather than numerical figures.

Phrenology

A debunked historical pseudoscience that claimed character and personality traits could be inferred from the shape and contours of the human skull.

Scientific Theory

A thoroughly tested, confirmed explanation that unifies extensive observations and data to explain why phenomena happen in the natural world.

Scientific Law

A statement that describes or predicts what is expected to happen under specific conditions, without necessarily explaining the underlying cause.

C-E-R Model

A scientific argumentation framework consisting of a Claim (conclusion statement), Evidence (experimental data and observations), and Reasoning (scientific principles connecting data to the claim).