Darwin and Natural Selection

Natural Selection

The process by which individuals with inherited traits better suited to their environment tend to survive and reproduce more effectively than others.

Fitness

Reproductive success in a given environment, not equivalent to physical strength or agility.

Inherited traits

Characteristics or features that are passed from parents to offspring.

Population variation

Differences among individuals within a population that may affect their survival and reproduction.

Environmental adaptation

The process by which a species becomes better suited to its environment over time.

Acquired traits

Traits that individuals develop during their lifetime, which are not heritable.

Example of Constraint in Evolution

The concept that certain traits, like the number of cervical vertebrae in mammals, are highly conserved and resistant to change.

Peppered Moths Case Study

Illustrates natural selection where light-colored moths were favored pre-industrial era, then dark moths became favored during industrialization due to pollution.

Nylon-Eating Bacteria

Paenarthrobacter ureafaciens KI72, a mutant strain capable of digesting nylon, demonstrating adaptation via mutation.

Speciation

The evolution of new species that occurs due to geographic isolation or other factors.

Artificial Selection

The process by which humans breed plants and animals for desired traits.

Darwin’s blending inheritance theory

An early, incorrect theory that offspring are a mixture of their parents' traits, supplanted by Mendelian genetics.

Legal rulings on 'creation science'

Legal decisions that reject 'creation science' as non-scientific due to lack of testability.

Nonoverlapping Magisteria

Stephen Jay Gould’s concept that science and religion address different realms and can coexist without conflict.

Survival of the Fittest

A phrase often used to describe the process of natural selection where only the organisms best adapted to their environment survive.

Gene Pool

The total genetic diversity found within a population or species.

Adaptive Radiation

The process by which organisms rapidly evolve into a variety of forms to adapt to different environments.

Bottleneck Effect

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

Founder Effect

A phenomenon where new populations are established by a small number of individuals from a larger population, leading to reduced genetic variation.

Fitness Landscape

A representation of how fitness varies with different genetic or phenotypic combinations.

Mutation

A change in the DNA sequence that can lead to new traits and variations in a population.

Natural Selection Pressure

Environmental factors that favor certain phenotypes over others, influencing survival and reproduction.

Homologous Structures

Anatomical features in different species that share a common ancestry, illustrating evolutionary relationships.

Analogous Structures

Body parts in different species that serve similar functions but do not share a common evolutionary origin.