Bio. II Lecture Exam 1 Flashcards
Evolution
Gradual genetic change in species over generations, driving biodiversity and adaptation.
Population
A group of interbreeding organisms of the same species in one area.
Gene pool
Collective set of genes in a population, influencing genetic diversity.
Genotypic frequencies
Quantifies how common a specific genotype is in a sample population.
Allele frequencies
Relative occurrence of specific alleles in a population’s gene pool.
Hardy-Weinberg Principle
allele frequencies in a population will not change from generation to generation. THIS CANNOT HAPPEN, BECAUSE EVERYTHING EVOLVES
Natural selection
Process where favorable traits enhance an organism’s survival and reproduction.
Adaptation
Evolutionary process where traits improve an organism’s fitness in an environment.
Artificial selection
Controlled breeding to promote specific traits in domesticated organisms.
Natural selection
Mechanism of evolution where advantageous traits increase in a population.
Mutation
Permanent alteration in DNA sequence, source of genetic diversity.
Gene flow
Exchange of genetic material between interbreeding populations, influencing diversity.
Dispersal agents
Organisms or forces aiding in seed or spore distribution.
Genetic drift
the change in frequency of an existing gene variant in the population due to random chance.
Population bottlenecks
Drastic reduction in population size, reducing genetic diversity.
Founder effect
Genetic variation in new population from a small founding group.
Nonrandom mating
Mating preferences that affect genotype frequencies within a population.
Bottleneck effect
Sharp reduction in a population’s size, often due to catastrophe.
Fossil Record
Compilation of all known fossils, showing life’s history.
habitats
Specific environments where organisms live and interact with their surroundings.
Radiometric
Dating method using decay of radioactive isotopes to determine age.
Plate tectonics
Theory explaining Earth’s crust movement through plates interactions.
mantle
Earth’s layer beneath the crust, composed of solid, hot rock.
Continental drift
Hypothesis proposing continents moved over geologic time due to plate tectonics.
Pangaea
Supercontinent that existed about 335 million years ago, later broke apart.
Geological change
Alterations in Earth’s structure or features over geological time.
Biogeography
Study of organisms’ distribution patterns in relation to geographical areas.
Convergent evolution
Unrelated species evolve similar traits due to similar environments.
analogous structures
Different structures in organisms with similar functions, evolved independently.
analogous structures
Different structures in organisms with similar functions, evolved independently.
Homology
Similarity in structure or function due to shared evolutionary ancestry.
analogy
Similarity in function or structure due to convergent evolution, not ancestry.
Vestigial Structures
Organs or features with reduced or no function in present-day organisms.
Embryonic development
Process from fertilization to birth, forming an organism’s body.
Fetal development
Growth and maturation of a developing organism during gestation.
Molecular clock
Estimate of evolutionary time using genetic sequence differences.
Reproductive isolation
Mechanisms preventing interbreeding between different species, maintaining species boundaries.
Prezygotic
Reproductive barriers preventing formation of hybrid zygotes pre-fertilization.
Postzygotic
Isolation occurs after the zygote is formed
Allopatric speciation
Formation of new species due to geographic isolation of populations.
Sympatric speciation
Formation of new species in the same geographic area.
Extinction
Complete disappearance of a species from the Earth’s surface.
K-T
Geological boundary marking the mass extinction of dinosaurs and more. 65 Million years ago
Adaptive radiation
Diversification of species into various ecological niches from a common ancestor.
Cladistics
Biological classification based on shared ancestry, emphasizing evolutionary relationships.
Taxonomic hierarchy
Systematic classification of organisms into ranks or categories.
Geographical barrier
Physical obstacles or features (e.g., mountains, rivers) that impede gene flow between populations, leading to speciation.
Laurasia
Ancient supercontinent in the Northern Hemisphere, part of Pangaea’s breakup.
Gondwana
Ancient supercontinent in the Southern Hemisphere, part of Pangaea’s breakup.
Soft-bodied organisms
Organisms lacking hard external structures like shells or skeletons. They don’t turn into fossils.
Hardy-Weinberg Principle (Full)
Hardy-Weinberg Principle states genetic equilibrium is only possible if all of the following conditions are met:
No mutations are occurring
The population is closed to migration from other populations
The population is infinitely large
All genotypes survive and reproduce equally well
Individuals in the population mate randomly
