BIO Vocab Study 4-1-4-4

4-1 VOCAB

• Evolution – The process by which species change over time through genetic variation and natural selection.

• Common Descent – The principle that all living organisms share a common ancestor.

• Speciation – The formation of new and distinct species due to evolutionary processes.

• Species – A group of organisms that can interbreed and produce fertile offspring.

• Adaptation – A trait that improves an organism’s ability to survive and reproduce.

• Reproductive Isolation – When different populations can no longer interbreed, leading to speciation.

• Behavioral Isolation – When species develop different mating behaviors that prevent interbreeding.

• Temporal Isolation – When species reproduce at different times, preventing interbreeding.

• Geographic Isolation – When physical barriers prevent species from interbreeding.

• Phylogeny – The evolutionary history and relationships among species.

4-2 VOCAB

• Natural Selection – The process where organisms with advantageous traits survive and reproduce more.

• Artificial Selection – The selective breeding of organisms to produce desired traits.

• Niche – The role and environment a species occupies in an ecosystem.

• Fitness – An organism’s ability to survive and reproduce in its environment.

• Struggle for Existence – The competition for limited resources among organisms.

• Single Gene Trait – A trait controlled by only one gene.

• Polygenic Trait – A trait influenced by multiple genes, leading to a range of variations.

• Directional Selection – When individuals with one extreme of a trait are favored.

• Stabilizing Selection – When individuals with an average form of a trait have higher fitness.

• Disruptive Selection – When individuals with extreme traits are favored over the average.

4-3 VOCAB

• Fossil – The preserved remains or traces of ancient organisms.

• Fossil Record – The collection of fossils that provides evidence for evolution.

• Relative Dating – A method of determining a fossil’s age by comparing its position in rock layers.

• Index Fossil – A fossil used to help determine the relative age of rock layers.

• Radioactive Dating – A technique that uses radioactive decay to determine a fossil’s exact age.

• Half-Life – The time it takes for half of a radioactive substance to decay.

• Paleontologist – A scientist who studies fossils to learn about ancient life.

• Homologous Structure – Body parts in different species that have a similar structure but may serve different functions, indicating common ancestry.

• Vestigial Organ – A body part that has lost its original function due to evolution.

• Mass Extinction – A rapid and widespread decrease in the number of species on Earth.

4-4 VOCAB

• Geologic Time Scale – A timeline of Earth’s history based on major geological and biological events.

• Macroevolution – Large-scale evolutionary changes that occur over long periods.

• Adaptive Radiation – The rapid evolution of many species from a common ancestor to fill different ecological niches.

• Convergent Evolution – When unrelated species evolve similar traits due to similar environments.

• Coevolution – The process where two species evolve in response to each other.

• Gene Pool – The total genetic material within a population.

• Genetic Drift – Random changes in allele frequencies that affect small populations.

• Founder Effect – When a new population is established by a small group, leading to reduced genetic variation.

• Relative Frequency – The proportion of a specific allele in a gene pool.

• Genetic Equilibrium – A state where allele frequencies in a population remain constant over time, meaning no evolution is occurring.