UNIT 2: Evolution Flashcards
Evolution
The cumulative change in heritable characteristics of a population over generations.
Fossils
Preserved remains or traces of organisms from the past
geological evidence
Layers of rock showing changes over time, supporting evolutionary timelines.
Lamarck’s theory
Suggested that traits acquired during an organism’s life are passed on to offspring (disproven).
Darwin’s theory
Natural selection drives evolution; favorable traits increase survival and reproduction.
Homologous Structures
Similar structures in different species due to common ancestry.
Analogous Structures
Structures with similar functions but different evolutionary origins.
Embryology
Similarities in early developmental stages among species suggest common ancestry.
molecular homologies
Genetic similarities (e.g., DNA sequences) showing evolutionary relationships
Biogeography
Geographic distribution of species, showing how species adapted to environments.
Natural selection
Process by which individuals better adapted to their environment survive and reproduce.
Mutations
Random changes in DNA that introduce genetic variation.
Sexual Reproduction
Combines genes, increasing variation.
Adaptations
Traits that increase an organism’s chances of survival and reproduction
Artificial Selection
Human-driven selection for desired traits
stabilizing selection
Favors intermediate phenotypes.
Directional Selection
Favors one extreme phenotype.
Disruptive Selection
Favors both extremes of phenotypes.
Fossil Record
Shows gradual changes over time in species
Comparative Anatomy
Structural similarities between organisms.
Molecular Biology
DNA and protein comparisons reveal relationships.
Biogeography
Patterns of distribution align with evolutionary history.
Coevolution
Mutual influence of two species on each other’s evolution.
Sexual Selection
Traits preferred by mates enhance reproductive success.
