Evolution and Natural Selection - Blooket

Adaptation

A trait that helps an organism survive and reproduce

Species

A group of similar organisms that can breed and produce fertile offspring.

disruptive selection

form of natural selection in which a single curve splits into two; occurs when individuals at the upper and lower ends of a distribution curve have higher fitness than individuals near the middle. Can lead to speciation.

behavioural isolation

form of reproductive isolation in which 2 populations have differences in courtship rituals or other types of behaviour that prevent them from interbreeding.

bottleneck genetic drift

->an entire species goes through a "bottle neck" which is when most of the individuals in the species dies. ->a bottle neck could be a volcanic eruption in which 90% of the mountain goats die.

Evidence of evolution

->the fossil record ->vestigial structures ->homologous structures of living organisms ->similarities in early development (embryology) ->comparative biochemistry (DNA) -> real time observation

4 steps of natural selection

1. genetic variation within the species 2. more offspring produced than can survive 3. struggle for existence (competition for resources) 4. differential reproduction and survival (fitness)

genetic drift

A change in the allele frequency of a population as a result of chance events rather than natural selection.

Sexual selection

A form of natural selection in which individuals with certain inherited characteristics are more likely than other individuals to obtain mates.

Acquired characteristics

A modification or change in an organ or tissue during the lifetime of an organism due to use, disuse, or environmental effects, and not inherited. Larmarck created this concept.

Absolute Dating

A technique used to determine the actual age of a fossil with the knowledge of half-lives

Natural selection

A process in which individuals that have certain inherited traits tend to survive and reproduce at higher rates than other individuals because of those traits. Darwin's mechanism of evolution.

Vestigial structures

A structure that is present in an organism but no longer serves its original purpose.

Fitness

Ability of an organism to survive and reproduce in its environment

Adaptive radiation

An evolutionary pattern in which many species evolve from a single ancestral species.

Mutation

Change in a DNA sequence that affects genetic information

Evolution

Change over time; process by which modern organisms have descended from ancient organisms.

gene pool

Combined genetic information of all the members of a particular population

Punctuated equilibrium

Describes this pattern of long, stable periods interrupted by brief periods of more rapid change

Charles Darwin

English natural scientist who formulated a theory of evolution by natural selection (1809-1882)

Molecular evidence

Evidence in DNA that shows evolution has occurred. Like the similarity in DNA between Chimpanzees and humans.

Miller-Urey Experiment

Experiment that found that organic molecules can form in a strongly reducing atmosphere.

Directional selection

Form of natural selection in which the entire curve moves; occurs when individuals at one end of a distribution curve have higher fitness than individuals in the middle or at the other end of the curve

geographic isolation

Form of reproductive isolation in which two populations are separated physically by geographic barriers such as rivers, mountains, or stretches of water

Speciation

Formation of new species

Relative Dating

Method of determining the age of a fossil by comparing its placement with that of fossils in other layers of rock

Gene flow

Movement of alleles from one population to another

Stabilizing selection

Natural selection that favors intermediate variants by acting against extreme phenotypes.

Co-Evolution

Process by which two species evolve in response to changes in each other

convergent evolution

Process by which unrelated organisms independently evolve similarities when adapting to similar environments

Artificial selection

Selection by humans for breeding of useful traits from the natural variation among different organisms

Homologous structures

Structures in different species that are similar because of common ancestry.

Allopatric

The formation of new species in populations that are geographically isolated from one another.

Sympatric

The formation of new species in populations that live in the same geographic area but are no longer utilizing the same behaviors

Law of Superposition

The geologic principle that states that in horizontal layers of sedimentary rock, each layer is older than the layer above it and younger than the layer below it.

Gradualism

The theory that evolution occurs slowly but steadily.

Jean-Baptiste Lamarck

This man developed the first cohesive theory of evolution after his studies of biology. He proposed that by selective use or disuse of organs, organisms could acquire or lose certain traits which are then passed on to their children and future generations, eventually changing the species

Theory

Well-tested explanation that unifies a broad range of observations

diveregent evolution

When closely related species evolve in different directions, they become increasingly different

bottleneck effect

a reduction in the genetic diversity of a population caused by a reduction in its size

Fossil record

by comparing fossils from older rock layers with fossils from younger layers, scientists could document the fact that life on Earth has changed over time

founder effect

change in allele frequencies as a result of the migration of a small subgroup of a population ex. Amish

struggle for existence

competition among members of a species for food, living space, and the other necessities of life

descent with modification

principle that each living species has descended, with changes, from its ancestors over time

survival of the fittest

process by which individuals that are better suited to their environment survive and reproduce most successfully; the process called natural selection

reproductive isolation

separation of species or populations so that they cannot interbreed and produce fertile offspring - may lead to speciation

Similarities in early development (embryology)

the groups of embryonic cells develop in the same order and in similar patterns to produce the tissues and organs of all vertebrates. These common cells and tissues growing in similar ways, produce the homologous structures