BIOL 2325 - Zoology Lecture 1: Scientific Method & Evolution

Comprehensive vocabulary flashcards covering the introductory concepts of zoology, the hypothetic-deductive method, Darwinian evolutionary theory, speciation mechanisms, and macroevolutionary patterns.

Zoology

The scientific study of animal life, derived from the Greek terms "zoon" (animal) and "logo" (discourse on or study of).

Hypothetic-deductive Method

The scientific process of formulating an educated guess and conducting empirical tests designed to potentially lead to its rejection.

Natural History

The scientific practice of gathering observations of the natural world and constructing broad patterns to explain natural phenomena.

Hypothesis

An educated guess formulated in response to questions about natural phenomena; it is derived from prior observations or theories and can attain the status of a theory if powerful in explaining diverse related phenomena.

Prediction (Scientific Method)

A quantitative or qualitative statement required to statistically test a hypothesis, typically capable of graphical representation.

Proximate Causes

Biological explanations addressing the "how" questions of life processes (such as physiology, metabolism, and behaviour), typically investigated via experimental approaches.

Ultimate Causes

Biological explanations addressing the "why" questions of organismal characteristics (such as the evolutionary origin and diversification of traits), typically evaluated via comparative approaches.

Phylogeny

A branching diagram whose lines represent evolutionary lineages depicting common descent; ancestral species reside at the base, current species at the tips, and branch splits designate speciation events.

Lamarckism

An early evolutionary concept proposed in 1809 by Jean Baptiste de Lamarck asserting that transformational evolution occurs via the inheritance of acquired characteristics shaped by the use and disuse of body parts.

Principle of Uniformitarianism

A geological principle advanced by Sir Charles Lyell stating that chemical and physical laws remain constant across time, meaning past geological occurrences were driven by natural processes identical to those observed in the present.

Perpetual Change

The core premise of evolutionary theory stating that the living world and its organismal characteristics undergo ongoing modifications across generations over time, as documented by the fossil record.

Common Descent

The evolutionary principle holding that all forms of life descend from a single common ancestor through a continuous branching of lineages.

Homology

Structural or physiological characteristics inherited with modification from a corresponding feature present in a shared common ancestor, as seen in vertebrate limb bones.

Ontogeny

The complete developmental history of an individual organism from an egg or bud through adulthood to death.

Multiplication of Species

The evolutionary process whereby new species are generated through the splitting and transformation of older ancestral lineages over time.

Allopatric Speciation

Speciation resulting from the geographic isolation of populations, such as the evolutionary divergence of sea urchins (Eucidaris tribuloides and Eucidaris thouarsi) following the closure of the Isthmus of Panama $2.8\text{ million}$ years ago.

Sympatric Speciation

A speciation process in which individuals diverge into distinct species while coexisting within different ecological niches or components of the same geographic environment.

Parapatric Speciation

An intermediate mode of speciation where diverging populations maintain geographically contiguous ranges that meet at an ecological boundary, but individuals do not cross.

Adaptive Radiation

The rapid evolutionary diversification of many ecologically disparate species from a single ancestral lineage into diverse vacant niches, exemplified by Darwin's finches.

Gradualism

The postulate that substantial phenotypic differences characterizing distinct species arise through the continuous accumulation of small, incremental modifications over long geological periods.

Phyletic Gradualism

An evolutionary model illustrated by continuous, smooth branching over time, portraying steady divergence through intermediate anatomical forms.

Punctuated Equilibrium

A 1972 evolutionary theory stating that phenotypic divergence is concentrated in brief, rapid episodes of speciation followed by prolonged periods of morphological stasis.

Adaptation

An anatomical structure, physiological mechanism, or behavioural trait that enhances an organism's survival and reproductive output in its environment.

Natural Selection

The process by which individuals possessing favourable adaptations survive and reproduce at higher rates, thereby increasing the frequency of advantageous traits in a population over successive generations.

Neo-Darwinism

A modification of Darwin's evolutionary framework established after August Weismann disproved the inheritance of acquired traits, integrating Mendelian genetics and chromosomal inheritance into evolutionary theory.

The Synthetic Theory (Modern Darwinism)

An evolutionary model formulated by population geneticists in the 1930s that integrates mathematics and genetics to define evolution as changes in gene and allele frequencies over time.

Microevolution

Evolutionary change on a small scale, specifically involving shifts in the frequencies of different allelic forms within a population's gene pool.

Macroevolution

Large-scale evolutionary patterns and events unfolding over geological timescales, including speciation rates, mass extinctions, and species selection.

Species Selection

The differential survival and proliferation of entire species lineages governed by traits such as mating systems, social structures, dispersal capabilities, and geographic ranges.

Permian Extinction

A catastrophic mass extinction event occurring approximately $225\text{ million}$ years ago that resulted in the disappearance of half of all shallow-water invertebrate families and $90\%$ of all marine invertebrate species.

Cretaceous Extinction

A major mass extinction event occurring approximately $65\text{ million}$ years ago associated with an asteroid impact at the Chicxulub Crater in Mexico, terminating non-avian dinosaurs and numerous other taxa.

Marine Mass Extinction Pulses

Periodic reductions in marine family diversity across geological time, documenting the Ordovician, Devonian, Permian, Triassic, and Cretaceous mass extinctions.