AP Bio: Evolution (unit 7)

Haploid

A cell that contains a single set of chromosomes.

Diploid

A cell containing two sets of chromosomes.

Protobionts/Protocells

The first formed cells, aggregates of abiotically produced organic molecules surrounded by a membrane, precursors of cells.

Endosymbiosis Model

A model explaining how organelles in eukaryotic cells evolved from symbiotic relationships between different organisms.

Miller-Urey Experiment

An experiment that simulated early Earth conditions and resulted in the formation of organic molecules, providing evidence for the origin of life.

Half-life

The time needed for a parent isotope to decay by 50%.

Radiometric Dating

A technique for determining the age of materials by measuring the amounts of radioactive isotopes and their decay products.

Continuous Drift

The phenomenon where landmasses drift apart over geological time.

Fossil Record

The history of life as documented by fossils, which is incomplete due to various factors.

Gene Flow

The transfer of alleles between populations through immigration and emigration.

Genetic Drift

Chance events that result in alterations of allele frequencies within a population.

Founder Effect

A form of genetic drift that occurs when a small group of individuals establishes a new population.

Bottleneck Effect

A sharp reduction in the size of a population due to environmental events or human activities, leading to a loss of genetic diversity.

Natural Selection

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

Comparative Embryonic Development

The study of similarities in the embryonic development of different species, used to determine evolutionary relationships.

Homologous Structures

Anatomical features in different organisms that share a common ancestry.

Analogous Structures

Traits that are similar due to convergent evolution, not because of common ancestry.

Eukarya

The domain of life composed of all organisms with cells containing true nuclei.

Archaea

A domain of prokaryotic organisms that are distinct from bacteria and inhabit extreme environments.

Eubacteria

The domain of prokaryotic organisms that are commonly known as bacteria.

Chi-Squared Test

A statistical method used to determine whether there is a significant difference between observed and expected frequencies.

Hardy-Weinberg Equilibrium

The condition under which allele frequencies in a population remain constant over generations, indicating no evolution.

Allopatric Speciation

Speciation that occurs when a biological population becomes geographically isolated.

Sympatric Speciation

Speciation that occurs without geographic isolation, often through reproductive isolation mechanisms.

Gradualism

The theory that evolution occurs slowly and steadily through small, incremental changes.

Punctuated Equilibrium

The theory that evolution occurs in rapid bursts followed by long periods of stability.

Vestigial Structures

Body parts that have lost their original function through evolution.

Artificial Selection

The intentional breeding of organisms to produce desired traits.

Mutations

Changes in the DNA sequence of an organism, which can lead to new traits.

Sexual Selection

A form of natural selection where individuals with certain traits are more likely to be chosen as mates.