AP Biology Unit 7

Microevolution

Ongoing genetic changes in a population that suggest evolution can happen quickly.

Natural Selection

Process where individuals with favorable traits survive and reproduce at higher rates, increasing the frequency of those traits in a population.

Darwin's Theory of Evolution

Proposes 'descent with modification', meaning current species are descendants of ancestral species.

Fitness

The ability of an organism to survive and produce fertile offspring.

Hardy-Weinberg Principle

A principle stating that genetic variation in a population remains constant in the absence of disturbing factors.

Gene Flow

Movement of alleles among populations through the transfer of fertile individuals or gametes.

Genetic Drift

A process where allele frequencies change suddenly from one generation to the next, especially in small populations.

Bottleneck Effect

A sharp reduction in the size of a population due to environmental events, leading to loss of genetic variation.

Speciation

The process by which one species splits into two or more species.

Abiotic Synthesis

The formation of organic molecules from inorganic components in the early Earth atmosphere.

Miller-Urey Experiment

An experiment that demonstrated the abiotic synthesis of organic molecules in a reducing atmosphere.

Phylogeny

The evolutionary history of a species or groups of related species.

Ingroup vs Outgroup

Ingroup refers to the species being studied; outgroup is a closely related species not part of the ingroup.

Adaptive Radiation

The process by which natural selection leads to a wide variety of forms from a common ancestor.

Reproductive Isolation

The inability of different species to interbreed and produce viable, fertile offspring.

Homology

The similarity of structures resulting from common ancestry.

Vestigial Structures

Remnants of features that served important functions in an organism’s ancestors but no longer serve a purpose.

Analogous Traits

Traits that arise when species independently adapt to similar environments, leading to convergent evolution.

Species Concept Limitations

Limitations include its applicability to fossils and asexual organisms, and the occasional gene flow between distinct species.

Extinction

The end of an organism's existence, often due to rapid environmental changes.

RNA world

The hypothetical early stage of life where RNA molecules played a crucial role in self-replication and catalysis.