BIOL1XX7: Ecological Systems, Biodiversity, and Biotechnology

Comprehensive vocabulary flashcards covering microbial ecology, biotechnology, conservation biology, environmental pollutants, community ecology, food webs, population dynamics, and behavioural ecology from the lecture series.

One Health

A global healthcare and ecological framework recognized by the World Health Organization (WHO) and pharmacy sectors which dictates that human health, animal health, and ecosystem health are fundamentally inseparable.

Biogeochemistry

The multidisciplinary field where biology, chemistry, and geology meet, describing biological processes that drive the transformation and cycling of chemical matter across the planet at global scales.

Autotroph

A self-nourishing organism that utilizes inorganic carbon dioxide ($CO_2$) as its carbon source, serving as the primary entry point of carbon into all food webs ($CO_2$ in, organic carbon out).

Photoautotroph

An autotroph that captures light energy to convert carbon dioxide ($CO_2$) and water into sugars and oxygen ($O_2$), functioning as a vital atmospheric $CO_2$ sink.

Chemoautotroph

An autotrophic organism that synthesizes organic carbon from carbon dioxide using chemical energy derived from inorganic reactions without the use of sunlight.

Methanogens

Ancient, strictly anaerobic Archaea that evolved $>3.5$ billion years ago which use carbon dioxide as a carbon source and hydrogen as an energy source through the reaction $CO_2 + 4H_2 \rightarrow CH_4 + 2H_2O$, releasing potent methane gas.

Heterotroph

An organism that requires organic molecules for both its carbon and energy requirements, acting as a carbon dioxide ($CO_2$) source by releasing fixed carbon back into the atmosphere.

Methanotrophs

Specialized heterotrophic bacteria that consume methane ($CH_4$) as both their carbon and energy source, oxidizing it via the enzyme methane monooxygenase (MMO) into carbon dioxide ($CO_2$) and water ($H_2O$).

Bioremediation

The application of microbial metabolic diversity to break down, remove, or neutralize toxic environmental pollutants from contaminated soil, water, or industrial sites.

Zooxanthellae

Symbiotic photosynthetic dinoflagellates living within the gastrodermal tissues of cnidarian corals, supplying up to $90\%$ of the coral animal's energy requirements.

Coral Bleaching

The stress response wherein coral animals expel their symbiotic zooxanthellae when sea surface temperatures rise $1\text{–}2\,^\circ\text{C}$ above baseline, turning the host coral white and leading to starvation.

Lichen Symbiosis

A mutualistic composite organism consisting of a heterotrophic fungal partner providing physical structure, water retention, and rock-weathering acids, combined with a photoautotrophic alga or cyanobacterium that provides photosynthetic sugars.

Molecular Biotechnology

Modern biotechnology that utilizes extensive molecular knowledge of the cell to manipulate cellular machinery, DNA sequences, and recombinant systems to manufacture medicinal and industrial products.

Molecular Cloning

The recombinant DNA technique of isolating a gene of interest, cleaving and ligating it into a suitable vector, and transforming host cells to replicate the DNA and express foreign proteins.

Plasmid

A small, circular, extrachromosomal DNA molecule occurring naturally in bacteria that replicates independently of chromosomal DNA and can transfer auxiliary traits such as antibiotic resistance.

Selectable Marker

A gene encoded on a cloning vector—such as an antibiotic resistance gene or metabolic enzyme—that enables researchers to select and identify host cells that have successfully acquired the recombinant plasmid.

Restriction Enzyme

A sequence-specific DNA-cleaving endonuclease used in molecular cloning to digest vector and foreign DNA strands to produce compatible ends for ligation.

Transformation

The step in molecular cloning where competent host cells take up naked foreign recombinant plasmid DNA from their extracellular environment.

Recombinant Vaccine

A vaccine manufactured by engineering host cells (such as yeast) with a cloned viral gene to express and purify non-pathogenic surface antigen proteins, such as the Hepatitis B surface antigen (HBsAg).

Critical Weight Range (CWR)

The body mass category between $35\,\text{g}$ and $5.5\,\text{kg}$ encompassing non-flying Australian terrestrial mammals that have suffered the greatest rates of extinction and population decline.

Bramble Cay Melomys

A Torres Strait rodent native to Bramble Cay that became the first documented mammalian extinction directly caused by anthropogenic climate change.

Michael Soulé

The founding pioneer of conservation biology who established it as a multidisciplinary synthetic science integrating biological and social fields to prevent species extinctions.

Evil Quartet

Jared Diamond's classification of the four primary forces driving species extinctions: alien species, overhunting, habitat loss, and co-extinction.

HIPPO

Edward O. Wilson's acronym identifying the five major anthropogenic extinction forces: Habitat destruction, Invasive species, Pollution, human over-Population, and Over-harvesting.

Tens Rule

Williamson and Fitter's empirical statistical rule stating that approximately $1$ in $10$ introduced exotic species escape to the wild, $1$ in $10$ of those naturalize, and $1$ in $10$ of those naturalized species become invasive pests.

Extinction Debt

The predicted, time-delayed future loss of species resulting inevitably from current habitat destruction and fragmentation, occurring generations after the initial impact.

Co-extinction

The loss of an affiliated species following the extinction of another organism upon which it obligately depends, such as host-specific parasites or mutualistic pollinators.

Population Viability Analysis (PVA)

A quantitative demographic modelling method used to integrate population size, vital rates, and environmental variation to forecast the extinction probability of a population over time.

Minimum Viable Population (MVP)

The smallest population threshold required for a species to have a high statistical probability of persisting over an extended temporal window, such as $100$ or $1,000\,\text{years}$.

Ecological Restoration

The active process of repairing human-induced damage to the biological diversity, ecological structure, and dynamics of indigenous native ecosystems.

Contaminant

Any physical substance or chemical found in an environmental medium where it should not naturally occur, or present at concentrations exceeding baseline natural levels.

Pollutant

An environmental contaminant present at sufficient concentrations to induce adverse biological effects or fitness impairment in exposed resident communities.

Bioaccumulation

The net uptake and retention of a toxic chemical by an individual organism occurring when absorption rates exceed the biological rate of metabolic elimination or excretion.

Biomagnification

The trophic phenomenon whereby the tissue concentration of a bioaccumulative pollutant progressively increases at successively higher consumer levels within a food web.

Global Distillation

The geochemical process wherein volatile persistent organic pollutants evaporate from warm lower latitudes, travel long distances through the atmosphere, and condense into polar environments.

Biomass Collapse

The abrupt loss of above-ground living plant biomass observed near newly created forest fragment edges, driven by altered edge microclimates, desiccation, and accelerated tree mortality.

Ecological Meltdown

A severe ecological collapse occurring in isolated, predator-free habitat fragments where the lack of top-down predation unleashes hyperabundant herbivores and seed predators that eliminate plant regeneration.

Community

A naturally occurring collection of populations of two or more distinct species that co-occur in the same spatial and temporal boundaries and interact with one another as an ecological unit.

Assemblage

A group of species co-occurring within a defined spatial area without any explicit assumptions regarding whether or how they ecologically interact with one another.

Primary Succession

The sequence of ecological community development and plant colonization that begins on newly exposed geological surfaces that completely lack pre-existing soil and biological organisms.

Secondary Succession

The process of ecological community re-assembly and replacement occurring in areas where a preceding community has been disturbed, but where established soil and viable seed banks remain intact.

Pioneer Species

Early-successional plant or microbial species characterized by rapid growth rates, small dispersible propagules, short generation times, and high tolerance to intense sunlight and nitrogen-poor substrates.

Intermediate Disturbance Hypothesis

The ecological concept proposing that maximum local species richness is maintained at moderate frequencies and intensities of disturbance, which prevent competitive exclusion while allowing colonisation.

Ecological Resilience

The capacity of an ecosystem or ecological community to absorb environmental disturbances and return to its pre-disturbance equilibrium state without shifting into an alternate state.

Net Primary Productivity (NPP)

The total energetic rate at which an ecosystem's primary producers accumulate usable biomass, representing gross primary productivity minus the autotrophic respiratory energy expenditure.

Trophic Level

The discrete position an organism occupies in an ecosystem's energetic hierarchy, spanning primary producers, primary consumers, and secondary or tertiary predators.

Trophic Cascade

A top-down ecological process whereby changes in the abundance or predation pressure of apex predators produce reciprocal population changes in mesopredators, herbivores, and primary producers.

Energy Hypothesis

Elton's (1927) hypothesis stating that food chains are constrained to short lengths because roughly $90\%$ of energy is dissipated as heat between consecutive trophic levels, leaving inadequate energy at the top.

Dynamic Stability Hypothesis

The ecological hypothesis suggesting that food chain lengths are limited because long chains are dynamically fragile; environmental fluctuations at low trophic levels magnify upwards and cause apex predator extinction.

Mutualism

A symbiotic or free-living interspecific ecological interaction in which both participating organisms obtain positive fitness benefits ($+$ / $+$).

Amensalism

An ecological interaction where one participating organism experiences negative fitness or survival impacts while the other interacting organism remains entirely unaffected ($0$ / $-$).

Herbivory

The antagonistic ecological feeding interaction ($+$ / $-$) in which an animal consumer ingests plant tissues, acting as the largest mass biotic interaction on Earth.

Biological Species Concept

Ernst Mayr's species definition stating that species are groups of actually or potentially interbreeding natural populations that are reproductively isolated from other such groups.

Species Richness

The fundamental tally or total count of different species represented within a specified ecological community, sample, or geographical territory, denoted by $S$.

Species Diversity

A composite ecological index that simultaneously incorporates species richness and the relative abundance (evenness) of individuals across each species in a community.

Berger-Parker Index

A measure of diversity expressed as $D = 1 - \frac{N_{\max}}{N}$, which quantifies diversity inversely related to the relative dominance of the single most abundant species ($N_{\max}$) in sample size $N$.

Simpson's Diversity Index

A diversity metric calculated as $D = \frac{1}{\sum p_i^2}$, which measures the probability that two individuals randomly selected from a community will belong to distinct species.

Alpha ((\alpha)) Diversity

The local diversity representing the total count of species occurring within a single homogeneous area, habitat, or local community.

Beta ((\beta)) Diversity

The turnover or degree of differentiation in species identity and composition observed between different habitats or along environmental gradients.

Gamma ((\gamma)) Diversity

The total regional species richness measured across all ecosystems, landscapes, and constituent habitats combined within a broad geographical expanse.

Carrying Capacity

The theoretical maximum population size of a species that can be indefinitely sustained by a given environment's limiting resources, represented as $K$.

Logistic Growth

Density-dependent population growth described by the differential equation $\frac{dN}{dt} = rN\left(1 - \frac{N}{K}\right)$, where per capita growth declines as numbers approach the environmental carrying capacity $K$.

Closed Population

A population whose size changes exclusively via the demographic balance of births and deaths due to the complete absence of immigration and emigration ($N_{t+1} = N_t + \text{Births} - \text{Deaths}$).

Open Population

A population whose numerical abundance is governed by immigration and emigration events alongside local births and deaths ($N_{t+1} = N_t + \text{Births} - \text{Deaths} + \text{Immigrants} - \text{Emigrants}$).

Mark-Release-Recapture (MRR)

A census method estimating mobile animal population size using the proportion of marked animals recaptured in subsequent sampling, calculated as $N = \frac{Mn}{R}$.

Dendrochronology

The biological dating and chronological analysis of environmental events through the anatomical measurement of annual growth rings in the secondary xylem of trees.

Herbchronology

The scientific method of determining the chronological age of perennial herbaceous plants by identifying annual growth increments in the secondary root xylem.

Otoliths

Calcium carbonate ear-stones (sagittae, asterisci, and lapilli) located in the inner ear of bony fishes used to determine age and growth rates via annual deposition rings.

Metapopulation

A regional network of spatially separated local populations of the same species linked by dispersal corridors, characterized by localized extinctions and subsequent recolonizations.

Behavioural Ecology

The study of how an organism's behavioural decisions and actions are shaped by interactions with ecological selective pressures and their evolutionary significance.

Darwinian Fitness

An individual organism's relative contribution to the gene pool of the next generation through successful survival and reproduction.

Optimal Foraging Theory

An ecological behavioural model predicting that natural selection shapes animals to forage in a manner that maximizes their net energetic gain per unit time spent feeding.

Marginal Value Theorem

Charnov's foraging model predicting that a consumer should leave an increasingly depleted food patch when its instantaneous harvest rate drops to the average harvest rate across the broader habitat.

Giving-Up Density (GUD)

The measurable density of remaining food left unharvested by a forager within an experimental patch, reflecting the point where metabolic harvest rewards equal the perceived foraging and predation costs.

Batesian Mimicry

An antipredator evolutionary strategy wherein an otherwise palatable, harmless species gains protection from predation by evolving a morphological resemblance to an unpalatable or toxic model organism.

Intrasexual Selection

A form of sexual selection involving direct competition between individuals of the same sex (typically male-male contests) to secure reproductive access to mates, resulting in sexual size dimorphism or weapons.

Intersexual Selection

A form of sexual selection driven by mate choice, wherein individuals of one sex (typically females) display active preferences for specific display traits, ornaments, or courtship behaviours exhibited by the opposite sex.