BIO Final Flashcards
Genetic Drift
Evolutionary changes in allele frequencies due to random events, more significant in small populations.
Allele
Alternative forms of a gene that arise by mutation and are found at the same place on a chromosome.
Alpha Diversity
The number of species in a specific, smaller area or ecosystem.
Beta Diversity
The rate of change in species composition between different habitats or regions.
Gamma Diversity
The total number of species in a larger region or landscape.
Sympatric Speciation
Speciation occurring within the same geographic area, often due to genetic mutations or niche differentiation.
Allopatric Speciation
Speciation occurring due to geographic separation of populations
Keystone Species
A species with a disproportionately large impact on its ecosystem relative to its abundance.
Competitive Exclusion Principle
The principle that two species competing for the same limiting resource cannot coexist at constant population values.
Resource Partitioning
The process by which similar species exploit the limited resources in an ecological area without one species driving the others into extinction.
Latitudinal Diversity Gradient (LDG)
Definition: The increase in biodiversity as one moves from the poles toward the equator.
Museum Hypothesis
Definition: The concept that tropical regions preserve high biodiversity by maintaining species over long periods with low extinction rates.
Biological Species Concept
Definition: Defines species as groups of actually or potentially interbreeding natural populations that are reproductively isolated from other such groups.
Morphological Species Concept
Definition: Defines species based on physical characteristics and structural features.
Ecological Species Concept
Definition: Defines species based on their ecological niche and role in the ecosystem.
Genetic Species Concept
Definition: Defines species based on genetic similarity and distinctiveness.
Polyploidy
Definition: Having more than two complete sets of chromosomes.
Autopolyploidy
Definition: A type of polyploidy involving multiple chromosome sets from one species.
Allopolyploidy
Definition: A type of polyploidy that combines chromosome sets from different species.
Punctuated Equilibrium
Definition: The theory that species remain relatively unchanged for long periods, with rapid bursts of evolutionary change during short periods.
Gradual Speciation
Definition: The theory that species evolve through slow, continuous changes over long periods.
Genetic Drift
Definition: Random changes in allele frequencies in a population, more significant in small populations.
Founder Effect
Definition: A form of genetic drift where a new population is established by a small number of individuals, leading to reduced genetic diversity.
Bottleneck Effect
Definition: A form of genetic drift resulting from a drastic reduction in population size, leading to loss of genetic variation.
Gene Flow
Definition: The process by which traits that enhance survival and reproduction become more common in successive generations.
Stabilizing Selection
Definition: A type of natural selection that favors intermediate traits and selects against extreme variations.
Directional Selection
Definition: A type of natural selection that favors one extreme trait over others.
Disruptive (Diversifying) Selection
Definition: A type of natural selection that favors both extreme traits over intermediate ones.
Sexual Selection
Definition: A form of natural selection where traits that enhance mating success are favored.
Edge Effects
Definition: Changes in population or community structures that occur at the boundary of two habitats, often altering light, temperature, and predation.
Habitat Fragmentation
Definition: The breaking up of continuous habitat into smaller, isolated patches, leading to reduced species diversity and increased vulnerability to extinction.
Reproductive Isolation
Definition: Mechanisms that prevent different species from interbreeding, ensuring species integrity.
Hybrid Sterility
Definition: A postzygotic reproductive barrier where hybrids are sterile and cannot reproduce.
Hybrid Zone
Definition: A geographic area where interbreeding occurs between two species, producing hybrids.
Reinforcement
Definition: The process by which natural selection increases reproductive isolation between populations.
Adaptive Radiation
Definition: The rapid diversification of a single ancestral species into multiple new species adapted to different niches.
Vestigial Structures
Definition: Anatomical features that have lost their original function through evolution, reflecting ancestry.
Endemic Species
Definition: Species that are native to and found only within a specific geographic location.
Commensalism
Definition: A symbiotic relationship where one species benefits while the other is neither helped nor harmed.
Predation
Definition: An interaction where one species (predator) hunts and feeds on another (prey).
Rescue Effect
Definition: The immigration of individuals from a larger population to replenish declining populations on islands, enhancing their chances of recovery and persistence.
