Convergent evolutionConvergent evolution is the independent evolution of similar features in species of different lineages. Convergent evolution creates analogous structures that have similar form or function but were not present in the last common ancestor of those groups. The cladistic term for the same phenomenon is homoplasy. The recurrent evolution of flight is a classic example, as flying insects, birds, pterosaurs, and bats have independently evolved the useful capacity of flight.
MutationIn biology, a mutation is an alteration in the nucleic acid sequence of the genome of an organism, virus, or extrachromosomal DNA. Mutations result from errors during replication, mitosis, meiosis, or damage to DNA, which then may trigger error-prone repair or cause an error during replication (translesion synthesis). Mutations may also result from substitution, insertion or deletion of segments of DNA due to mobile genetic elements.
Parallel evolutionParallel evolution is the similar development of a trait in distinct species that are not closely related, but share a similar original trait in response to similar evolutionary pressure. Parallel vs. convergent evolutionConvergent evolution is the independent evolution of similar features in species of different lineages.
EvolutionChange in the heritable characteristics of populationsEvolution is the change in the heritable characteristics of biological populations over successive generations. It happens when individuals in a population vary in their genetic characteristics and in the numbers of their surviving offspring.
Lineage (evolution)An evolutionary lineage is a temporal series of populations, organisms, cells, or genes connected by a continuous line of descent from ancestor to descendant. Lineages are subsets of the evolutionary tree of life. Lineages are often determined by the techniques of molecular systematics. Phylogenetic representation of lineagesLineages are typically visualized as subsets of a phylogenetic tree.
Evolutionary biologyEvolutionary biology is a subfield of biology that analyzes the four mechanisms of evolution: natural selection, mutation, genetic drift, and gene flow. Natural selection was independently discovered as the engine of evolution by Charles Darwin and Alfred Russel Wallace, based on patterns in the geographic distribution of species. Gregor Mendel discovered the laws of . R. A. Fisher unified Darwin and Mendel in the modern synthesis.
Transition (genetics)Transition, in genetics and molecular biology, refers to a point mutation that changes a purinenucleotide to another purine (A ↔ G) or a pyrimidine nucleotide to another pyrimidine (C ↔ T). Transitions are common in genomes; approximately two out of three single nucleotide polymorphisms (SNPs) are transitions. Molecular basisTransitions can be caused by several mechanisms, including spontaneous deamination and tautomerization.Genetic driftGenetic drift is the change in the frequency of an existing allele in a population due to chance. Genetic drift may cause alleles to disappear completely and thereby reduce genetic variation. It can also cause initially rare alleles to become much more frequent possibly leading to fixation where the initially rare allele displaces all others.
AlleleAn allele (UK: ) is a variant of the sequence of nucleotides at a particular location, or locus, on a DNA molecule. Alleles can differ at a single position through single-nucleotide polymorphisms, but they can also have insertions and deletions of up to several thousand base pairs.
Natural selectionNatural selection is the differential survival and reproduction of individuals due to differences in the relative fitness endowed on them by their own particular complement of observable characteristics. It is a key law or mechanism of evolution which changes the heritable traits characteristic of a population or species over generations.
TransversionTransversion, in molecular biology, refers to a point mutation in DNA in which a single (two ring) purine (A or G) is changed for a (one ring) pyrimidine (T or C), or vice versa. A transversion can be spontaneous, or it can be caused by ionizing radiation or alkylating agents. It can only be reversed by a spontaneous reversion.*As an Amazon Associate I earn from qualifying purchases.