Principles of Evolution, Natural Selection, and Comparative Anatomy

Vocabulary practice flashcards covering the key principles of evolution, mechanisms and requirements of natural selection, evolutionary theorists (Lamarck and Darwin), and comparative anatomy evidence (homologous, analogous, and vestigial structures).

Evolution

Genetic changes in the characteristics of a species across generations, which forms new species over time.

Biodiversity

The genetic range of life within a population, ecosystem, or entire planet, which is driven and caused by evolution.

Species

A group of organisms that can interbreed in nature to produce viable and fertile offspring.

Speciation

The evolutionary process of forming new species over many generations, originating from one existing species that can split into multiple species.

Jean-Baptiste Lamarck

The first theorist to propose formal evolutionary theories, specifically the ideas of use and disuse and the inheritance of acquired traits.

Use and Disuse

A now-discredited evolutionary theory proposed by Jean-Baptiste Lamarck stating that unused characteristics are eventually lost while useful characteristics are developed and maintained within an organism's lifetime.

Inheritance of Acquired Traits

Lamarck's theory suggesting that modifications or traits developed by an organism during its lifetime can be directly passed down to its offspring.

Charles Darwin

The naturalist who developed the theory of natural selection after traveling around the world and observing organism variations, most notably at the Galapagos islands.

Natural Selection

The mechanism of evolution whereby organisms better adapted to their specific environment tend to survive and reproduce, increasing the frequency of advantageous traits in the population over time.

Variation (Natural Selection)

The differences in phenotypes that exist among individuals within a population, which arise through random mutations.

Selective Pressure

Environmental conditions or factors—such as predators, weather conditions, disease, or food and water availability—that favour the survival and reproduction of particular variants over others.

Selective Advantage

A phenotypic trait or characteristic that increases an individual's probability of surviving and successfully reproducing in a given environment.

Comparative Anatomy

The scientific study and comparison of anatomical structures across different species to discover structural and functional similarities that provide evidence for evolution.

Divergent Evolution

The pattern of evolution where two or more distinct species evolve from a single common ancestor due to different environmental selective pressures.

Adaptive Radiation

A form of rapid divergent evolution wherein an ancestral species rapidly diversifies into a large variety of new forms due to environmental change, as observed in Darwin's Galapagos finches.

Homologous Structures

Anatomical structures in different species that share a similar internal pattern or arrangement due to shared ancestry, but have evolved to perform different functions.

Pentadactyl Limb

A specialized homologous limb structure with five digits that originated from a common ancestral vertebrate and is adapted for various modes of locomotion across humans, cats, whales, and bats.

Convergent Evolution

The evolutionary pattern in which unrelated species without a recent common ancestor independently develop similar phenotypic traits as a result of facing similar selective pressures.

Analogous Structures

Anatomical features across different species that have different structural patterns and developmental origins but serve the same function, such as the wings of birds, bats, and pterodactyls.

Parallel Evolution

An evolutionary process where two related species sharing a common ancestor independently evolve similar characteristics in response to similar selective pressures.

Vestigial Structures

Functionless anatomical remnants in an organism that served a functional purpose at an earlier stage in its evolutionary history, such as the human appendix, coccyx, cassowary wings, or whale rear leg bones.