Bio 30 - Evolution Student Notes Review

Vocabulary practice flashcards based on the Bio 30 Evolution Student Notes, covering the history of evolutionary thought, natural selection, micro- and macroevolution, mammalian and human evolution, and anatomical adaptations.

Aristotle's View of Species

The philosophical perspective that species are fixed and unchanging, arranged on a ladder or scale of increasing complexity (Scala Naturae) where each perfect and permanent life-form occupies an allotted rung.

Uniformitarianism

A geological principle formulated by James Hutton and Charles Lyell stating that all features of the Earth's surface are produced by physical, chemical, and biological processes occurring over long periods of geological time.

Thomas Malthus

An economist who published 'Essay on the Principle of Population' in 1798, arguing that human famine and disease are inevitable consequences of population increase; his concept of struggle for existence inspired Darwin's theory of natural selection.

Use and Disuse Proposal

Jean-Baptiste de Lamarck's hypothesis that body parts used extensively become larger and stronger over an individual's lifetime, while unused structures shrink and deteriorate.

Inheritance of Acquired Characteristics

The disproven hypothesis proposed by Lamarck asserting that modifications gained by an organism during its lifetime can be directly passed down to its offspring.

Alfred Russel Wallace

A naturalist who collected specimens in the Malay Archipelago from 1854 to 1862 and independently arrived at the theory of natural selection, prompting a joint publication with Charles Darwin at the Linnean Society of London in 1858.

Four Key Principles of Natural Selection

The central tenets of Darwinian evolution: 1) production of a large number of offspring, 2) natural variation within a population, 3) limited resources and the struggle for survival, and 4) environmental selection for traits enabling survival and reproduction.

Microevolution

Processes of evolutionary change that take place within populations, resulting in shifts at the DNA level and leading to observable variations within a species.

Medium Ground Finch (Daphne Major Study)

A seed-eating Galápagos finch studied by Peter and Rosemary Grant for $39$ years ($1973$-$2012$) that showed observable evolutionary shifts in beak size within one generation due to environmental droughts and rains.

Industrial Melanism in Peppered Moths

The rapid shift in the frequency of light/mottled and dark peppered moth morphs during the Industrial Revolution, where soot-covered bark favoured dark moths ($98\%$ in cities) due to camouflage from bird predators.

Mammalian Middle Ear

A key anatomical defining characteristic of Class Mammalia consisting of three small skull bones: the malleus, incus, and stapes.

Amniotes

A clade of tetrapods possessing a terrestrially adapted egg enclosed by specialized tissue layers (chorion, amnion, yolk sac, and allantois) that prevent desiccation and nourish the developing embryo.

Synapsid

A member of an amniote clade leading to mammals, distinguished by a single opening (temporal fenestra) on each side of the skull behind the eye socket where jaw muscles anchor.

Adaptive Radiation of Mammals

A rapid period of diversification spanning approximately $20$ million years following the late Cretaceous ($\text{K-Pg}$) extinction of large dinosaurs, marine reptiles, and pterosaurs, giving rise to modern mammalian orders.

Sahelanthropus tchadensis

The oldest known extinct hominin fossil species, living approximately $6.5$ million years ago.

Homo erectus

The first hominin species to migrate out of Africa, with its oldest known fossils dating back approximately $1.8$ million years.

Serial Founder Effect / Global Genetic Gradient

The pattern wherein human genetic diversity steadily decreases with geographical distance from Africa, leaving Africa with the highest diversity and regions colonized last (the Americas and Oceania) with the lowest.

Macroevolution

Evolutionary changes that take place above the species level over long periods of geological time, such as the emergence of terrestrial tetrapods from marine ancestors.

Homologous Structures

Body structures across different species that share an underlying anatomical plan derived from a common ancestor, even though their functions may diverge (e.g., human arm, bat wing, whale flipper).

Analogous Structures

Anatomical features in different species that serve similar functions but do not share a common ancestral structure, having evolved independently (e.g., bat wings versus insect wings).

Three Criteria for Recognizing Homologies

The anatomical benchmarks used by biologists to identify homologous traits: 1) same basic structure, 2) same relational connections to other skeletal features, and 3) same developmental origin from embryonic buds.

Vestigial Structures

Anatomical features that have lost their original ancestral function through natural selection over time, such as the human coccyx (tailbone).

Tetrapod Limb Archetype

A shared skeletal plan inherited from a $350$-million-year-old common ancestor, consisting of one proximal long bone (humerus) attached to two distal long bones (radius and ulna).

Basilosaurus and Dorudon

Extinct, fully aquatic whale ancestors discovered in Wadi Hitan (Egypt's 'Valley of the Whales') from the Eocene epoch ($56$-$33$ million years ago) possessing vestigial hind limbs complete with pelvis, kneecap, and toes.

Marine Mammal Swimming Motion

The characteristic up-and-down undulation of the spine in marine mammals, contrasting with the lateral side-to-side motion of fish, reflecting their evolutionary origin from four-legged terrestrial mammals.

Antimicrobial Resistance (AMR)

An evolutionary process driven by natural selection where bacteria, viruses, fungi, or parasites survive drug treatment due to resistance genes, proliferating and rendering standard medicines ineffective.

Giraffe Elastic Neck Ligament

An anatomical adaptation that acts like an elastic band to support the giraffe's straight neck posture and conserve energy during movement without requiring continuous muscular effort.

Recurrent Laryngeal Nerve

An anatomical historical legacy in vertebrates where the nerve travels from the brain, loops around the aorta, and ascends back to the larynx, reflecting an ancestral fish circulatory layout rather than an optimal direct path.