BIO120 course flashcards

Evolutionary Biology

The study of the processes and patterns of evolutionary change in biological organisms.

Natural Selection

The process by which organisms better adapted to their environment tend to survive and produce more offspring.

Adaptation

Any trait that enhances an organism's ability to survive and reproduce in a given environment.

Microevolution

Evolutionary changes within a species over time.

Macroevolution

Evolutionary changes observed at or above the level of species.

Biodiversity

The variety of life in a particular habitat or ecosystem.

Phylogenetic Tree

A diagram that shows the evolutionary relationships among various biological species based on similarities and differences in genetic or physical traits.

Vestigial Structures

Anatomical features that are remnants of an organism's evolutionary past and have lost their original function.

Homology

The similarity of traits in different species that arises from shared ancestry.

Mutation

A stable change in the DNA sequence that can lead to variations in traits within a population.

Genotype

The genetic constitution of an individual organism.

Phenotype

The observable physical or biochemical characteristics of an organism, determined by both genetic makeup and environmental influences.

Gene Flow

The transfer of genetic material between populations, affecting genetic diversity.

Inbreeding Depression

The reduced biological fitness in a given population due to inbreeding.

Directional Selection

A form of natural selection that favors one extreme of a trait's variation.

Stabilizing Selection

A form of natural selection that favors average traits and reduces variability.

Disruptive Selection

A form of natural selection that favors extremes over intermediate phenotypes.

Phenotypic Plasticity

The ability of an organism to change its phenotype in response to environmental changes.

Artificial Selection

The process by which humans breed specific traits in organisms.

Founder Effect

A decrease in genetic variation that occurs when a new population is established by a small number of individuals from a larger population.

Transitional Fossils

Fossils that show the intermediate states between an ancestral form and that of its descendants, supporting evolutionary theory.

Galapagos Islands

An archipelago known for its unique species that contributed to Charles Darwin's formulation of the theory of natural selection.

Differential Fitness

The varying ability of individuals with different phenotypes to survive and reproduce in a given environment.

Neoteny

The retention of juvenile traits in the adult form of an organism.

Selective Sweep

A process where a beneficial mutation spreads through a population, reducing genetic variation at nearby loci.

Genetic Drift

Random changes in allele frequencies in a population due to chance events.

Endemism

Species that are native to and restricted to a particular geographic region.

Adaptive Radiation

The rapid evolution of diversely adapted species from a common ancestor.

Common Ancestor

An ancestral species from which multiple descendant species evolve.

Speciation

The process through which new species arise.

Behavioral Adaptation

Changes in behavior that enhance survival and reproductive success.

Ecological Niche

The role and position a species has in its environment, including all interactions with the biotic and abiotic factors.

Alleles

Different versions of a gene that can exist at a specific locus.

Quantitative Genetics

The study of the genetic basis of complex traits that are influenced by multiple genes.

Biological evolution

change in inherited attributes of populations across generations —> explains the orgin of biological diversity at all scales of organization.

Uniformitarianism

everything came about through things we can observe at any time (ex. erosion, earthquakes)

Variation

individual variation in a population

Heredity 

progeny resemble their parents morethan unrelated individuals

Fitness

genetic contribution of individuals to next generation, relative to other individuals as a result of differences in viability and fertility

Independent assortment 

the alleles of 2 genes will segregate into daughter cells independent  - allows different combinations of parental chromosomes of one another

Fixation

occurs when a polymorphic locus becomes monomorphic due to the loss of all

but one allele —> occurs through natural selection or genetic drift

Polymorphism

proportion of gene loci that have 2 or more alleles in the population

Outbreeding

mates are LESS closely related than random

Inbreeding

mates are MORE closely related than random

Outcrossing

mating with someone else (fusion of gametes from 2 parents)

Selfing

mating with yourself (but not asexual reproduction)

Population

a group of individuals of a single species occupying a given area at a given time

Migration

the movement of individuals from one population to another

Stochastic

unpredictable/random

Deterministic

predictable/non-random