Evolutionary Ecology and Anthropocene Vocabulary

Flashcards covering the glossary and key concepts from the lecture notes, including terms related to the Anthropocene, quantitative genetics, speciation, and physiological adaptation to climate change.

Anthropocene

A proposed geological epoch where human activity is the dominant influence on Earth's geology and ecosystems.

Megafauna

Large-bodied animals, typically those over $1000\,kg$ (e.g., mammoths, giant armadillos), many of which went extinct due to human arrival.

Fundamental Niche

The range of environmental conditions a species can theoretically occupy based solely on abiotic tolerances.

Realised Niche

The actual environment a species occupies after accounting for both abiotic stressors and biotic interactions like predation and competition.

Trait-Environment Mismatch

A condition where the evolved traits of an organism are no longer suited to its rapidly changing environment, leading to reduced fitness and performance.

Maladaptive Trap

A situation where an organism follows a historical cue (such as polarised light) to make a choice that is now harmful to its fitness due to environmental changes.

Metabolic Mismatch

A specific human mismatch where evolved energy-saving traits lead to disease in an environment with an overabundance of calories.

Chronic Physiological Stress

A modern condition where the body's rapid stress response is triggered by persistent, non-physical pressures rather than the short-term physical threats it evolved to handle.

Evolutionary Rescue

A process where a population that is declining because of environmental change is \"rescued\" by an adaptive evolutionary response that restores positive population growth.

Genetic Drift

The random fluctuation of allele frequencies in a population due to chance events, typically leading to a reduction in genetic variation.

Fixation

The process by which one allele becomes the only variant for a gene in a population, resulting in the loss of other alleles.

Standing Genetic Variation

The existing variety of different alleles and traits within a population at a given time.

Stabilising Selection

A form of selection that erodes variation and pushes a population toward the highest possible fitness optima, often by eliminating deleterious mutations.

Directional Selection

A form of selection that favours one extreme phenotype, pushing the population in a specific direction.

Disruptive Selection

A form of selection that favours both extremes and selects against the intermediate form.

Genetic correlation

A situation where one gene influences multiple traits, meaning selection for one trait is tied to the expression of others.

Y-Model (Acquisition-Allocation)

A conceptual model explaining that because available energy is finite, organisms must allocate resources between three primary competing needs: growth, reproduction, and maintenance.

Pleiotropy

A genetic condition where one single gene underpins two or more phenotypic traits, creating a link that natural selection cannot easily pull apart.

Local Adaptation

The evolutionary process where a population develops specific traits that increase its fitness in its immediate environment compared to how it would perform in other environments.

Phenotypic Plasticity

The ability of a single genotype to produce multiple different phenotypes depending on the environmental conditions within a generation.

Reaction Norm

A visual or mathematical representation of the range of phenotypes that a single genotype can produce across different environments.

Genotype x Environment (G x E) Interaction

Occurs when different genotypes respond differently to environmental changes, evidenced by differing slopes in their reaction norms.

Polyphenism

A type of plasticity where distinct, discrete phenotypes (morphs) are produced by the same genotype in response to environmental cues, such as seasonal colour morphs.

Transgenerational Plasticity

A non-genetic mechanism where the parental environment influences the traits of the offspring via epigenetic, cytoplasmic, or nutritional factors.

Common Garden Experiment

An experimental design where individuals from different populations are reared under identical environmental conditions to attribute differences to genetic changes.

Reciprocal Transplant Experiment

A test for local adaptation involving transplanting populations into both home and foreign environments to see if the \"home\" population outperforms the \"away\" population.

Climatic Variability Hypothesis (Janzen’s Hypothesis)

The idea that tropical organisms have narrower thermal breadths due to low annual climatic variation, while high-latitude organisms have broader tolerances due to variable climates.

Heritability ($h^2$)

The proportion of phenotypic variation in a population that is attributable to genetic variation; it determines how much of a parent's trait is passed to its offspring.

Breeder's Equation

The mathematical relationship ($R = h^2 \times S$) used to predict how much a population will change based on selection pressure and genetic inheritance.

Extinction Vortex

A downward spiral where small population size and genetic factors (drift and inbreeding) reinforce each other to drive a population toward extinction.

Antagonistic Pleiotropy

A specific type of pleiotropy where a genetic variant has a beneficial effect on one trait but a detrimental effect on another.

Thermal Performance Curve (TPC)

A framework describing the relationship between environmental temperature and an organism’s fitness or performance.

Critical Thermal Maximum ($CT_{max}$)

The upper physiological ceiling or temperature limit beyond which an organism can no longer function or survive.

Thermal Safety Margin

The gap or difference between the maximum temperature an organism can tolerate and the actual temperature of its environment.

Carcisation

A real evolutionary pattern within crustaceans where a crab-like body form evolves multiple times in independent lineages.

Path Dependence

The idea that the history of a lineage and its past evolutionary changes limit and shape the options available for future adaptation.

Entrenchment

A state where a biological system becomes so integrated into development and gene regulation that it is difficult for evolution to alter it.

Phylogenetic Niche Conservatism

A phenomenon where ecological niches remain stable over time because the traits defining them are inherited and conserved.

Biological Species Concept

A group of actually or potentially interbreeding natural populations that are reproductively isolated from other such groups.

Dobzhansky-Muller Theory

A genetic model explaining how reproductive isolation can evolve through incompatible interactions between multiple genes that evolved separately in different populations.

Ecological Speciation

The process by which reproductive isolation evolves between populations as a result of ecologically-based divergent selection.

Reinforcement

The evolution of increased reproductive isolation between two populations due to selection against the production of low-fitness hybrids.

Introgression

The movement of a gene from one species into the gene pool of another by the repeated backcrossing of an interspecific hybrid with one of its parent species.

Evolutionary Trap

A scenario where an organism relies on a previously reliable cue to make a decision that actively reduces its fitness, often preferring the harmful option.

Spatial Sorting

The non-random accumulation of individuals with high dispersal traits at the front of an expanding population.

Red Queen Hypothesis

An evolutionary concept where species must constantly adapt just to maintain relative fitness in the face of ever-evolving predators, competitors, or parasites.

Bogert Effect

The phenomenon where behavioral thermoregulation prevents a species from being exposed to selection for higher physiological heat tolerance.

Eco-evolutionary Feedbacks

A reciprocal process where ecological changes drive evolution, and those evolved traits subsequently alter ecological dynamics.