Evolution, Natural Selection, and Evidence for Evolution

Vocabulary flashcards covering core concepts in evolutionary theory, patterns of evolution, natural selection mechanisms, speciation, anatomical and genetic evidence, and Science as a Human Endeavour (SHE).

Evolution

The change in the inherited characteristics and genetic makeup of biological populations over successive generations, occurring at the population level rather than within individual organisms.

Scientific Theory

A comprehensive, well-substantiated explanation of aspects of the natural world that is supported by a large body of evidence and repeated testing, distinct from a preliminary hypothesis or a descriptive law.

Hypothesis

A tentative, testable proposed explanation or prediction for an observed phenomenon that can be supported or refuted through experimentation and observation.

Scientific Law

A statement or mathematical description of an observed pattern or regular phenomenon in nature that consistently occurs under specific conditions, without necessarily explaining why it happens.

Charles Darwin

A naturalist who made foundational contributions to evolutionary theory by proposing the mechanism of natural selection to explain how species adapt and evolve over time.

Divergent Evolution

A pattern of evolution where two or more closely related species originate from a common ancestor and accumulate distinct structural or functional differences over time.

Convergent Evolution

A pattern of evolution in which unrelated or distantly related species independently develop similar traits or adaptations as a result of experiencing similar environmental selection pressures.

Adaptive Radiation

A rapid form of divergent evolution where a single ancestral species diversifies into multiple distinct species, each adapted to occupy different ecological niches.

Co-evolution

A reciprocal evolutionary pattern where two or more interacting species exert mutual selection pressures on each other, causing each to evolve in response to adaptations in the other.

Natural Selection

The evolutionary mechanism by which individuals with advantageous inherited traits survive and reproduce at higher rates, causing those traits to become more frequent in the population across generations.

Variation

The presence of genetic and phenotypic differences in characteristics and traits among individuals of the same population.

Selection Pressure

Any external biotic or abiotic environmental factor that alters the survival or reproductive success of individuals possessing particular phenotypes within a population.

Adaptation

An inherited phenotypic feature or trait that improves an individual organism's fitness, survival, and reproductive success in a given environment.

Species

A group of morphologically and genetically similar organisms capable of interbreeding in nature to produce viable, fertile offspring.

Speciation

The evolutionary process through which ancestral populations diverge and become reproductively isolated, resulting in the formation of one or more new species.

Reproductive Isolation

The presence of biological, structural, behavioral, or temporal barriers that prevent individuals of different populations or species from successfully interbreeding and producing viable, fertile offspring.

Geographical Isolation

A mechanism of isolation resulting from physical spatial barriers, such as mountains, bodies of water, or habitat fragmentation, that physically prevent populations from interacting and mating.

Behavioural Isolation

A form of reproductive isolation occurring when species or populations fail to interbreed due to differences in courtship rituals, mating calls, or display behaviors.

Temporal Isolation

A form of reproductive isolation that prevents gene flow because two populations reproduce at different times, such as different hours of the day, different seasons, or different years.

Pre-zygotic Isolation Mechanisms

Reproductive barriers that prevent mating or fertilization from occurring between species, preventing the formation of a zygote.

Post-zygotic Isolation Mechanisms

Reproductive barriers that occur after fertilization has taken place, leading to inviable offspring, hybrid developmental failure, or hybrid sterility.

Fossils

The preserved remains, impressions, or traces of ancient organisms found in rock layers, providing physical evidence of past life and phenotypic changes over geological time.

Comparative Anatomy

The study and comparison of body structures and anatomical features across different species to identify evolutionary relationships and patterns of common descent.

Homologous Structures

Anatomical structures found in different species that share a common ancestral origin and structural plan, though they may serve different functions.

Analogous Structures

Anatomical features in different species that perform similar biological functions and appear similar, but evolved independently without deriving from a common ancestor.

Vestigial Structures

Rudimentary anatomical structures or organs that have lost most or all of their ancestral function over the course of evolutionary history.

Biogeography

The scientific study of the spatial and geographic distribution of biological organisms across the planet, illustrating how historical movements and continental shifts relate to evolutionary history.

Science as a Human Endeavour (SHE)

A scientific inquiry framework focused on the application of scientific knowledge, the social and environmental context of scientific developments, and the recognition of limitations and evidence-based reasoning.