The relationships of groups of organisms as reflected by their genetic makeup.

The process of cumulative change at the level of DNA; RNA; and PROTEINS, over successive generations.

The naturally occurring transmission of genetic information between organisms, related or unrelated, circumventing parent-to-offspring transmission. Horizontal gene transfer may occur via a variety of naturally occurring processes such as GENETIC CONJUGATION; GENETIC TRANSDUCTION; and TRANSFECTION. It may result in a change of the recipient organism's genetic composition (TRANSFORMATION, GENETIC).

The restriction of a characteristic behavior, anatomical structure or physical system, such as immune response; metabolic response, or gene or gene variant to the members of one species. It refers to that property which differentiates one species from another but it is also used for phylogenetic levels higher or lower than the species.

Processes occurring in various organisms by which new genes are copied. Gene duplication may result in a MULTIGENE FAMILY; supergenes or PSEUDOGENES.

Theoretical representations that simulate the behavior or activity of genetic processes or phenomena. They include the use of mathematical equations, computers, and other electronic equipment.

The systematic study of the complete DNA sequences (GENOME) of organisms.

A multistage process that includes cloning, physical mapping, subcloning, determination of the DNA SEQUENCE, and information analysis.

A field of biology concerned with the development of techniques for the collection and manipulation of biological data, and the use of such data to make biological discoveries or predictions. This field encompasses all computational methods and theories for solving biological problems including manipulation of models and datasets.

A procedure consisting of a sequence of algebraic formulas and/or logical steps to calculate or determine a given task.

The process of cumulative change over successive generations through which organisms acquire their distinguishing morphological and physiological characteristics.

Functions constructed from a statistical model and a set of observed data which give the probability of that data for various values of the unknown model parameters. Those parameter values that maximize the probability are the maximum likelihood estimates of the parameters.

Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.

Double-stranded DNA of MITOCHONDRIA. In eukaryotes, the mitochondrial GENOME is circular and codes for ribosomal RNAs, transfer RNAs, and about 10 proteins.

The arrangement of two or more amino acid or base sequences from an organism or organisms in such a way as to align areas of the sequences sharing common properties. The degree of relatedness or homology between the sequences is predicted computationally or statistically based on weights assigned to the elements aligned between the sequences. This in turn can serve as a potential indicator of the genetic relatedness between the organisms.

A theorem in probability theory named for Thomas Bayes (1702-1761). In epidemiology, it is used to obtain the probability of disease in a group of people with some characteristic on the basis of the overall rate of that disease and of the likelihood of that characteristic in healthy and diseased individuals. The most familiar application is in clinical decision analysis where it is used for estimating the probability of a particular diagnosis given the appearance of some symptoms or test result.

Remains, impressions, or traces of animals or plants of past geological times which have been preserved in the earth's crust.

The intergenic DNA segments that are between the ribosomal RNA genes (internal transcribed spacers) and between the tandemly repeated units of rDNA (external transcribed spacers and nontranscribed spacers).

DNA sequences encoding RIBOSOMAL RNA and the segments of DNA separating the individual ribosomal RNA genes, referred to as RIBOSOMAL SPACER DNA.

The splitting of an ancestral species into daughter species that coexist in time (King, Dictionary of Genetics, 6th ed). Causal factors may include geographic isolation, HABITAT geometry, migration, REPRODUCTIVE ISOLATION, random GENETIC DRIFT and MUTATION.

Constituent of the 40S subunit of eukaryotic ribosomes. 18S rRNA is involved in the initiation of polypeptide synthesis in eukaryotes.

Genotypic differences observed among individuals in a population.

Deoxyribonucleic acid that makes up the genetic material of CHLOROPLASTS.

Constituent of 30S subunit prokaryotic ribosomes containing 1600 nucleotides and 21 proteins. 16S rRNA is involved in initiation of polypeptide synthesis.

A field of study concerned with the principles and processes governing the geographic distributions of genealogical lineages, especially those within and among closely related species. (Avise, J.C., Phylogeography: The History and Formation of Species. Harvard University Press, 2000)

Constituent of the 60S subunit of eukaryotic ribosomes. 28S rRNA is involved in the initiation of polypeptide synthesis in eukaryotes.

The genetic complement of MITOCHONDRIA as represented in their DNA.

The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.

The systematic arrangement of entities in any field into categories classes based on common characteristics such as properties, morphology, subject matter, etc.

Warm-blooded vertebrate animals belonging to the class Mammalia, including all that possess hair and suckle their young.

Members of the group of vascular plants which bear flowers. They are differentiated from GYMNOSPERMS by their production of seeds within a closed chamber (OVARY, PLANT). The Angiosperms division is composed of two classes, the monocotyledons (Liliopsida) and dicotyledons (Magnoliopsida). Angiosperms represent approximately 80% of all known living plants.

Genes that are located on the MITOCHONDRIAL DNA. Mitochondrial inheritance is often referred to as maternal inheritance but should be differentiated from maternal inheritance that is transmitted chromosomally.

The science dealing with the earth and its life, especially the description of land, sea, and air and the distribution of plant and animal life, including humanity and human industries with reference to the mutual relations of these elements. (From Webster, 3d ed)

Gymnosperms are a group of vascular plants whose seeds are not enclosed by a ripened ovary (fruit), in contrast to ANGIOSPERMS whose seeds are surrounded by an ovary wall. The seeds of many gymnosperms (literally, "naked seed") are borne in cones and are not visible. Taxonomists now recognize four distinct divisions of extant gymnospermous plants (CONIFEROPHYTA; CYCADOPHYTA; GINKGOPHYTA; and GNETOPHYTA).

Animals that have no spinal column.

Deoxyribonucleic acid that makes up the genetic material of plants.

Self-replicating cytoplasmic organelles of plant and algal cells that contain pigments and may synthesize and accumulate various substances. PLASTID GENOMES are used in phylogenetic studies.

Members of the phylum Arthropoda, composed of organisms having a hard, jointed exoskeleton and paired jointed legs. It includes the class INSECTS and the subclass ARACHNIDA, many species of which are important medically as parasites or as vectors of organisms capable of causing disease in man.

The most abundant form of RNA. Together with proteins, it forms the ribosomes, playing a structural role and also a role in ribosomal binding of mRNA and tRNAs. Individual chains are conventionally designated by their sedimentation coefficients. In eukaryotes, four large chains exist, synthesized in the nucleolus and constituting about 50% of the ribosome. (Dorland, 28th ed)

'Primates' is a taxonomic order comprising various species of mammals, including humans, apes, monkeys, and others, distinguished by distinct anatomical and behavioral characteristics such as forward-facing eyes, grasping hands, and complex social structures.

A set of genes descended by duplication and variation from some ancestral gene. Such genes may be clustered together on the same chromosome or dispersed on different chromosomes. Examples of multigene families include those that encode the hemoglobins, immunoglobulins, histocompatibility antigens, actins, tubulins, keratins, collagens, heat shock proteins, salivary glue proteins, chorion proteins, cuticle proteins, yolk proteins, and phaseolins, as well as histones, ribosomal RNA, and transfer RNA genes. The latter three are examples of reiterated genes, where hundreds of identical genes are present in a tandem array. (King & Stanfield, A Dictionary of Genetics, 4th ed)

The variety of all native living organisms and their various forms and interrelationships.

One of the three domains of life (the others being BACTERIA and ARCHAEA), also called Eukarya. These are organisms whose cells are enclosed in membranes and possess a nucleus. They comprise almost all multicellular and many unicellular organisms, and are traditionally divided into groups (sometimes called kingdoms) including ANIMALS; PLANTS; FUNGI; and various algae and other taxa that were previously part of the old kingdom Protista.

The genetic complement of an organism, including all of its GENES, as represented in its DNA, or in some cases, its RNA.

The genetic complement of a BACTERIA as represented in its DNA.

Warm-blooded VERTEBRATES possessing FEATHERS and belonging to the class Aves.

Animals having a vertebral column, members of the phylum Chordata, subphylum Craniata comprising mammals, birds, reptiles, amphibians, and fishes.

Genes, found in both prokaryotes and eukaryotes, which are transcribed to produce the RNA which is incorporated into RIBOSOMES. Prokaryotic rRNA genes are usually found in OPERONS dispersed throughout the GENOME, whereas eukaryotic rRNA genes are clustered, multicistronic transcriptional units.

The ceasing of existence of a species or taxonomic groups of organisms.

The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.

The sequential correspondence of nucleotides in one nucleic acid molecule with those of another nucleic acid molecule. Sequence homology is an indication of the genetic relatedness of different organisms and gene function.

The relationship between two different species of organisms that are interdependent; each gains benefits from the other or a relationship between different species where both of the organisms in question benefit from the presence of the other.

Multicellular, eukaryotic life forms of kingdom Plantae (sensu lato), comprising the VIRIDIPLANTAE; RHODOPHYTA; and GLAUCOPHYTA; all of which acquired chloroplasts by direct endosymbiosis of CYANOBACTERIA. They are characterized by a mainly photosynthetic mode of nutrition; essentially unlimited growth at localized regions of cell divisions (MERISTEMS); cellulose within cells providing rigidity; the absence of organs of locomotion; absence of nervous and sensory systems; and an alternation of haploid and diploid generations.

A set of statistical methods used to group variables or observations into strongly inter-related subgroups. In epidemiology, it may be used to analyze a closely grouped series of events or cases of disease or other health-related phenomenon with well-defined distribution patterns in relation to time or place or both.

A phylum of fungi which have cross-walls or septa in the mycelium. The perfect state is characterized by the formation of a saclike cell (ascus) containing ascospores. Most pathogenic fungi with a known perfect state belong to this phylum.

A plant division that includes hornworts, named for the horn-like appearance of the spore-producing plant (sporophyte).

A suborder of PRIMATES consisting of the following five families: CHEIROGALEIDAE; Daubentoniidae; Indriidae; LEMURIDAE; and LORISIDAE.

One of the three domains of life (the others being BACTERIA and Eukarya), formerly called Archaebacteria under the taxon Bacteria, but now considered separate and distinct. They are characterized by: (1) the presence of characteristic tRNAs and ribosomal RNAs; (2) the absence of peptidoglycan cell walls; (3) the presence of ether-linked lipids built from branched-chain subunits; and (4) their occurrence in unusual habitats. While archaea resemble bacteria in morphology and genomic organization, they resemble eukarya in their method of genomic replication. The domain contains at least four kingdoms: CRENARCHAEOTA; EURYARCHAEOTA; NANOARCHAEOTA; and KORARCHAEOTA.

A functional system which includes the organisms of a natural community together with their environment. (McGraw Hill Dictionary of Scientific and Technical Terms, 4th ed)

Deoxyribonucleic acid that makes up the genetic material of bacteria.