Evolution Vocab

Vocab for evolution unit - BC Life Sciences 11

Adaptive Evolution

many related species evolve from one ancestral species.

Allele

An alternate form of a gene.

Allele frequency

The percentage of a specific allele of a gene in the gene pool.

Artificial selection

the selection of desirable traits in plants and animals through selective breeding by humans

Biological species concept

Classifying organisms solely by whether or not they naturally breed with one another and produce fertile offspring.

Chromatin

material that chromosomes are composed of and are made from DNA and proteins

Coevolution

The joint evolution of interacting species.

Complementary base pairing, and DNA and RNA pairs

The manger in which nitrogenous bases couple with one another in specific pairs. DNA - Adenine - Thymine, Cytosene - Guanine. RNA - Adenine - Uracil, Cytosene - Guanine.

Convergent evolution

The process by which unrelated species become more similar as they adapt in the same kind of environment. Cactus and Aloe plants similar cuticles

Divergent evolution

The process of two or more related species becoming more and more dissimilar. Galapagos finches.

DNA

Deoxyribonucleic acid. A double helix shaped nucleic acid that carries genetic code.

Double helix

Spiral shaped characteristic of the DNA molecule.

Evolution

Genetic change in a population or species over generations; all the changes that transform life on Earth; the heritable changes that have produced Earth’s diversity of organisms.

Gene

A segment of DNA that codes for a particular protein.

Gene flow

The movement of genes in or out of a population.

Gene pool

The collection of genes for all the traits in a population.

Genetic drift

A shift in allele frequencies in a population due to random events or change.

Genotype

The genetic composition of an individual (The set of alleles that an organism has)

Genetic equilibrium

A state of the gene pool in which the allele frequencies do not change from generation to generation.

Gradual change model

A model that describes evolution as a gradual change of species by small changes over a long period of time.

Macroevolution

Large scale evolutionary changes such as: new organs and organ systems, new body forms, new phyla.

Microevolution

Small scale evolutionary changes such as: shifts in allele frequency, bacteria forming antibiotic resistance, new varieties, subspecies and species.

Migration

The movement of individual organisms into or out of a population, community, or biome

Morphological species concept

The idea that organisms can be classified by differences in their appearance

Mutation

A change in the DNA

Natural selection

The process by which organisms with favorable variations survive and reproduce at higher rates than those without such variations.

Directional selection

A type of selection in which individuals with one of the extreme forms of a trait have an advantage in terms of survival and reproduction. Part of the types of natural selection, entire graph shifts toward one extreme. Shape stays the same, just shifts up or down the x-axis.

Disruptive selection

A type of selection in which individuals with either of the extreme forms of a trait have an advantage in terms of survival and reproduction. The average form of the traits confers a selective disadvantage to the individual. Part of natural selection, graph looks like two camel humps. There’s a rise in both extremes and a dip in the middle.

Sexual selection

The preferential choice for a mate based on the presence of a specific trait

Stabilizing selection

A type of selection in which the average form of a trait has an advantage in terms of survival and reproduction. Part of the types of natural selection, graph looks like the bump in the middle gets taller and the graph gets slimmer overall.

Nitrogenous base

The purines and pyrimidines that make up DNA

Non-random mating

Mating where the probability of two individuals mating is not equal to the probability of other individual pairs.

Phenotype

The way that the genotype is expressed in an organism. This could include how the organism looks (morphology) or the way it behaves.

Population

All the members of a species that live in the same area and make up a breeding group

Punctuated equilibrium model

A theory that speciation may occure during brief periods of rapid genetic change

Species

A group of individuals that look similar and whose members are capable of producing fertile offspring in the natural environment.

Speciation

The formation of a new species

Allopatric speciation

Formation of a new species when populations are geographically isolated

Sympatric speciation

Formation of a species when the populations are not geographically isolated

Spontaneous generation

The development of living organism from non-living material

Sugar-phosphate backbone

The structure that forms the sides of the double helix of DNA