Conservation Biology Exam 3

Overexploitation

The excessive use of natural resources, leading to depletion or population decline of species.

Super Predator

A term describing humans as an unsustainable predator that alters ecological and evolutionary processes.

Exponential Growth

Population increase where the growth rate is proportional to the current population size, requiring unlimited resources.

Logistic Growth

Population growth that slows as it reaches carrying capacity due to resource limitations.

Allee Effect

A phenomenon where a population's per capita fitness decreases when its size becomes too small.

Trophic Downgrading

The loss of top predators from an ecosystem, leading to cascading effects on lower trophic levels.

Seamount

An underwater volcanic mountain.

Guyot

An underwater volcanic mountain with a flat summit.

Constant Quota Exploitation

A harvesting strategy where a fixed number of individuals is removed from a population annually, which can lead to overexploitation if population sizes fluctuate.

Proportional (Constant Effort) Exploitation

A harvesting strategy where a constant fraction of the population is removed, making it more sustainable since harvest adjusts with population size.

Pleistocene Overkill Hypothesis

• 1: Extinction of Megafauna – Large-bodied mammals and birds, such as mammoths and giant ground sloths, were hunted to extinction by early humans.

• 2: Downsizing of Faunal Populations – The largest individuals or species in a given ecosystem became increasingly rare, leading to an overall decrease in body size across animal populations.

• 3: Ecosystem Consequences – The loss of large herbivores and predators caused cascading effects, such as reduced seed dispersal, increased fire intensity, and co-extinctions of scavengers dependent on megafauna carcasses.

Conservation Genetics

The study of genetic variation in populations to understand and mitigate biodiversity loss.

Modern Evolutionary Synthesis

The integration of Darwinian natural selection with Mendelian genetics (circa 1936-1947).

Central Dogma of Molecular Biology

The principle that genetic information flows from DNA to RNA to Protein but not in reverse.

Watson-Crick Model

The double-helix structure of DNA discovered by James Watson and Francis Crick in 1953.

Base Pair (bp)

A pair of nucleotides in DNA or RNA that forms the fundamental unit of genetic sequences.

Genotype

The genetic makeup of an organism, including all its alleles.

Phenotype

The observable traits of an organism, resulting from genotype and environmental influences.

Development

The process of gene expression leading to the formation of tissues, organs, and overall organismal structure.

Microevolution

Evolutionary changes within a population, affecting allele frequencies over time.

Heterozygosity

The presence of two different alleles at a specific locus on homologous chromosomes.

Fixation Index (FST)

A measure of genetic differentiation between subpopulations.

Hardy-Weinberg Equilibrium

A theoretical model where allele frequencies remain constant in a population unless acted upon by evolutionary forces.

Haplotype

A group of genes within an organism inherited together from a single parent.

Phylogenetic Tree

A diagram showing evolutionary relationships based on genetic similarities and differences.

Genetically Effective Population Size (Ne)

The number of individuals in a population that contribute to genetic diversity.

Extinction Vortex

A process where small populations experience reduced genetic diversity, leading to further decline.

Pedigree Analysis

The study of family lineage to understand genetic relationships.

Genetic Rescue

The introduction of new genetic material into an inbred population to increase diversity.

Eurasian Wolf

A severely bottlenecked wolf population that recovered genetic diversity after a single immigrant wolf arrived in 1991.

North American Wolf

A wolf population that experienced a genomic sweep due to an immigrant male in 1997.

Florida Panther

A population of endangered panthers that benefited from the introduction of eight females from Texas.

European Rabbits

An invasive spread triggered by a single release of wild-type rabbits in 1859.

Macroevolution

Large-scale evolutionary changes that lead to the emergence of new species.

Adaptive Radiation

The rapid evolution of multiple species from a common ancestor.

Last Universal Common Ancestor (LUCA)

The most recent common ancestor of all life on Earth.

Reticulate Evolution

Evolution involving hybridization and genetic exchange between distinct species.

Phylogenetic Diversity (PD)

A measure of how much evolutionary history is represented within a community.

Abiogenesis Hypothesis

The theory that life originated from non-living chemical compounds over 3.5 billion years ago.

Panspermia Hypothesis

The hypothesis that life did not originate on Earth but was brought here from elsewhere.

R.A. Fisher Fundamental Theorem

The rate of increase in fitness of any organism at any time is equal to its genetic variance in fitness at that time.

Erica Bree Rosenblum

Global Change Biology.

Joan Roughgarden

Variation originates through random mutation then natural selection acts to produce organic diversity.

Lamarck

Individuals acquire characteristics during their lifetimes and pass them on.

Adapt

A process in which a population evolves traits that increase fitness in response to environmental change.

Adjust

Short-term, individual-level changes in trait expression due to environmental variation.

Move

The movement of a population to a different geographic region in response to environmental changes.

Response-to-Mutation Narrative

Evolution occurs as new mutations create genetic variation, and natural selection acts on those mutations over time.

Response-to-Environment Narrative

Environmental changes first produce phenotypic variation, and selection later reinforces these changes through genetic shifts.

Heritability

The proportion of phenotypic variation in a population that is due to genetic variation.

Pleiotropy

A single gene influencing multiple traits, which can affect adaptation.

High-Altitude Human Adaptations

Different populations evolved distinct physiological adaptations to low oxygen (e.g., increased RBC production in Andeans vs. higher ventilation rates in Tibetans).

Tawny Owl Microevolution

Climate change has led to an increase in brown morph owls due to reduced snow cover.

Purple Urchin Adaptation to Ocean Acidification

Genetic variation allows some larvae to tolerate higher CO₂ levels, suggesting potential evolutionary responses.

Directional Selection

Selection that favors individuals at one extreme of a trait distribution (e.g., increase in beak size in Darwin’s finches).

Stabilizing Selection

Selection that favors intermediate trait values while selecting against extremes (e.g., birth weight in humans).

Disruptive Selection

Selection that favors individuals at both extremes of a trait distribution while selecting against intermediates (e.g., African seedcracker finches with different beak sizes).

Intersexual Selection

Selection driven by mate choice, favoring traits that increase attractiveness (e.g., peacock tail feathers).

Intrasexual Selection

Competition between individuals of the same sex for mates, favoring traits that enhance success in combat (e.g., large antlers in deer).

Invasive Species

A non-native species that establishes, spread within its new range, and has an appreciable negative impact on native organisms & ecosystems. (60% of extinctions, $423 billion annually)

Reintroduction

Anthropogenic placement of a species into a given place that was previously occupied by that species.

Native Species

An organism that came to be found in a given place by natural causes.

Non-native Species

An organism that came to be found in a given place by anthropogenic causes; also referred to as exotic, introduced, or non-indigenous.

Naturalized

A species that established itself in a non-native range, but causes no harm.

Biotic Resistance Hypothesis

The hypothesis suggesting that species-rich communities are more resistant to invasion.

Ecosystem Engineer

Species that directly or indirectly modulate the availability of resources to other species by causing physical state changes in biotic or abiotic materials.

Allogenic Ecosystem Engineer

Change the environment by transforming materials from the physical state to another.

Autogenic Ecosystem Engineer

Change the environment by transforming their own physical structures.

Keystone Species

A species whose effect on its community is disproportionately large relative to its abundance.

Keystone Predator

Maintain community stability.

Keystone Resource

Sustain plant through periods of food scarcity.

Foundation Species

Species that have a disproportionately important influence on the structure of the community.

Anthropocene (Paul Crutzen)

The current geological age viewed as the period during which human activity has been the dominant influence on climate and the environment.

Successful Invasion

Occurs when potential invaders establish thriving populations within a new environment due to:

• Traits of organisms

• Characteristics of focal site

Competitive Exclusion Principle

The ecological rule that two species competing for the same resource cannot coexist at constant population values.

Intentional Introduction

Agriculture, hunting, fishing, etc.

Unintentional Introduction

Transport and Escaped Pets

Environmental Filters

1. Regional species pool

2. Biogeographical filter (introduced species skip this)

3. Abiotic filter

4. Biotic filter

5. Local assemblage

Invasive Control Methods

• Chemical

• Biological

• Prevention

Tri-Trophic Interactions

• Competition

• Apparent Competition

• Indirect Mutualism

Emerging Pests

A species found where it is unwanted, over-abundant, or causing harm.

Population Expansion

Owing to trophic cascade and herbivore release from predation pressure.

Impact of Invasive Species

• Direct or Indirect

• Evolutionary

• Global

• Local

Daniel Simberloff

Non-indigenous species facilitate another’s invasion.

Species of Unusual Effect (SUEs)

• Keystone species

• Ecosystem engineer

• Foundation species

Parasite Escape Hypothesis

The idea that invasive species are often successful because they escape their natural enemies in new environments.

Spillover

A pathogen moves from one population to another.

Disease Reservoirs

Host population where a disease could survive.

SIR Model

Susceptible Host → Infected Host → Recovered/Immune Hosts

Reduce S_t

Achieve herd immunity by culling or vaccinating to reduce susceptible population.

Increase m

Improve early detection and clinical treatment to remove infected.

Reduce B

Quarantine infected

Range Expansion

Natural process where an organism immigrates to a given place on its own.