Intro to Ecology, Evolution, Physiological Ecology, and Nutrient Cycling Vocabulary

Vocabulary flashcards covering core concepts in ecology, evolution, physiological ecology, thermal regulation, water balance, and biogeochemical cycles.

Ecology

The study of how organisms interact with one another and with their physical environment.

Biotic Factors

Living components of an environment, such as organisms, that influence species distribution and abundance.

Abiotic Factors

Non-living physical and chemical components of an environment, such as temperature, water, nutrients, and sunlight.

Ecological Levels

The hierarchy of biological organization in ecology, structured from smallest to largest as individual, population, community, ecosystem, biome, and biosphere.

Mutation

A change in the genetic code of an organism that acts as the primary source of new genetic variation.

Ecological Trade-off

The balance of costs and benefits associated with a trait, constrained by environmental and biological factors, that determines how the trait evolves.

Charles Darwin

The naturalist on the HMS Beagle whose observations laid the foundation for evolutionary biology and ecology, proposing descent with modification and evolution by natural selection in On the Origin of Species (1859).

Gregor Mendel

The scientist known as the father of genetics who experimented with pea plants to discover and describe the basic laws of inheritance.

Population Genetics

A branch of biology formed by combining Mendelian genetics with Darwinian natural selection to study genetic differences and allele frequency changes within and between populations.

Allele

One of two or more alternative forms of a gene found at a specific chromosome locus.

Heterozygous

Having two different alleles for a specific gene on homologous chromosomes ($\text{Aa}$).

Homozygous

Having two identical alleles for a specific gene on homologous chromosomes ($\text{AA}$ or $\text{aa}$).

Genotype

The genetic constitution of an individual organism represented by its combination of alleles.

Phenotype

The observable physical, physiological, or behavioral characteristics of an organism produced by its genotype interacting with the environment.

Evolution

Changes in the frequencies of alleles in a population across generations.

Quantitative Trait

A trait that displays continuous variation rather than discrete categories, usually controlled by multiple genes and influenced by environmental factors.

Adaptation

A genetically influenced trait that evolved through natural selection and increases the reproductive fitness of individuals carrying it.

Local Adaptation

A condition where a population has evolved traits specific to its local environment, resulting in higher fitness for native individuals compared to non-local transplants.

Reciprocal Transplant Experiment

An experimental method used to test for local adaptation by interchanging individuals between two or more different environments and comparing their fitness.

Genetic Drift

Random fluctuations in allele frequencies from generation to generation due to chance events, exerting a stronger effect in small populations.

Founder Effect

A form of genetic drift occurring when a new population is established by a small number of colonizing individuals carrying a non-representative subset of genetic variation from the source population.

Bottleneck Effect

A form of genetic drift that occurs when a population undergoes a drastic reduction in size due to a critical environmental event, altering remaining allele frequencies.

Migration (Gene Flow)

The transfer of genetic material between distinct populations that alters allele frequencies.

Integrated Pest Management (IPM)

A pest management strategy combining multiple control tactics, such as high-dose applications and untreated refuge areas, to control pest damage while delaying the evolution of resistance.

Whittaker Biome Diagram

A plot that categorizes global terrestrial biomes according to their average annual temperature and average annual precipitation.

Physiological Tolerances

The upper and lower limits of abiotic environmental conditions, such as temperature and water availability, within which an organism can survive and function.

Niche

The complete range of physical, chemical, and biological conditions required for a species to survive, persist, and reproduce.

Law of the Minimum

The ecological principle stating that species distribution and growth are controlled by the essential resource that is available in the shortest supply relative to demand.

Phenotypic Plasticity

The capacity of a single genotype to express different phenotypic traits when exposed to different environmental conditions.

Acclimation

Reversible physiological or behavioral adjustments made by an individual organism during its lifetime to cope with changing environmental conditions.

Homeostasis

The physiological process by which an organism maintains stable internal conditions within its range of physiological tolerance.

Surface Area to Volume Ratio

The ratio of an organism's external surface area to its internal volume, which decreases as body size increases and governs rates of heat and water exchange with the environment.

Basal Metabolic Rate

The baseline energy expenditure per unit time required by a resting endothermic organism to maintain vital cellular functions and stay alive.

Conduction

The transfer of thermal energy between two objects in direct physical contact from higher temperature to lower temperature.

Convection

The transfer of heat between an object and a moving fluid medium, such as air or water.

Heat Balance Equation

The mathematical model for net heat gain ($\text{H}_{\text{NET}}$) expressed as $\text{H}_{\text{NET}} = \text{H}_{\text{AR}} + \text{H}_{\text{MET}} - \text{H}_{\text{RR}} \pm \text{H}_{\text{COND}} \pm \text{H}_{\text{CONV}} - \text{H}_{\text{E}}$.

Poikilotherm

An organism whose body temperature fluctuates along with changes in external ambient temperature.

Homeotherm

An organism that maintains a relatively constant internal body temperature despite fluctuations in external ambient temperature.

Heterotherm

An organism that can switch between self-regulating its body temperature (endothermy) and allowing its body temperature to track the environment (ectothermy), such as during hibernation.

Transpirational Cooling

The cooling of plant leaves driven by the latent heat lost when liquid water evaporates into water vapor and exits through open stomata.

Photorespiration

A metabolic pathway that occurs when Rubisco binds to $\text{O}_2$ instead of $\text{CO}_2$, consuming energy without producing sugar molecules.

Transpiration

The movement of water through a plant and its evaporation into the atmosphere primarily through leaf stomata.

Water Potential

A measure of the potential energy of water that determines the direction of water movement, flowing passively from regions of higher (less negative) water potential to lower (more negative) water potential.

Cavitation

The formation of air bubbles (embolisms) in plant xylem vessels resulting from high water tension generated during extreme transpiration.

Nutrient Pool

The quantity of a specific nutrient located within a designated compartment or reservoir of an ecosystem.

Nutrient Flux

The rate at which a nutrient transfers or transforms between different ecosystem pools over time.

Residence Time

The average length of time a nutrient element remains inside a given ecosystem pool, calculated as $\text{Residence Time} = \frac{\text{Pool Size}}{\text{Total Flux Out}}$.

Nitrification

The biological conversion of ammonium ($\text{NH}_4^+$) into nitrite ($\text{NO}_2^-$) and subsequently into nitrate ($\text{NO}_3^-$).

Denitrification

The microbial process in which nitrate ($\text{NO}_3^-$) is converted back into gaseous dinitrogen ($\text{N}_2$) and released into the atmosphere.

Nitrogen Fixation

The conversion of atmospheric nitrogen gas ($\text{N}_2$) into biologically accessible inorganic nitrogen forms such as ammonium ($\text{NH}_4^+$).

Nutrient Spiraling

The process in lotic aquatic systems where nutrients cycle between organic and inorganic forms while simultaneously moving downstream in water flow.

Thermal Stratification

The seasonal separation of a lake into thermal water layers, consisting of a warm upper layer (epilimnion), a transition layer (thermocline), and a cold bottom layer (hypolimnion).

Lake Turnover

The seasonal mixing of surface and bottom waters in a lake occurring in spring and fall that redistributes dissolved oxygen and nutrients throughout the water column.

Nutrient Retention Efficiency

The proportion of total nutrient inputs retained by an ecosystem, calculated as $\text{Retention Efficiency} = \left[\frac{\text{Retention Rate}}{\text{Inputs}}\right] \times 100\%$.