Key Definitions Flashcards
What is the fossil record?
The history of life documented by fossils, providing insight into evolutionary processes and extinct species
What is evolution?
The change in the heritable traits of populations over successive generations
What is natural selection?
A process where organisms better adapted to their environment tend to survive and reproduce
What is an extinction event?
A widespread and rapid decrease in biodiversity, often affecting global ecosystems
What is adaptive radiation?
The rapid diversification of a lineage into multiple species adapted to different environments
What is Darwinism?
The theory of biological evolution developed by Charles Darwin, stating that all species arise and develop through natural selection of small, inherited variations that increase the individual’s ability to survive and reproduce
What are the 2 requirements for natural selection?
- Genetic diversity within the population
- Selective pressure for heritable traits that affect fitness
What is speciation?
The evolutionary process by which populations evolve to become distinct species
What are the four types of speciation?
- Allopatric
- Sympatric
- Peripatric
- Parapatric
What is allopatric speciation?
Happens due to geographic isolation
What is sympatric speciation?
Happens due to a lack of physical barriers, often via ecological or behavioral divergence
What is peripatric speciation?
Happens due to a small peripheral population being isolated
What is parapatric speciation?
Happens due to neighboring populations evolving differences where ranges meet
What is genetic drift?
A random change in allele frequencies in a population, especially significant in small populations
What are the main types of generic drift?
- Bottleneck Effect
- Founder Effect
What is the bottleneck effect?
A sharp reduction in population size due to events like climate change, pollution, or bleaching
What is the founder effect?
When a new population is started by a small number of individuals, leading to reduced genetic variation
What is fitness?
An organism’s ability to survive and reproduce
