Search results
Results from the WOW.Com Content Network
In the late 1900s, strains were considered to belong to the same species if they had a DNA–DNA similarity value greater than 70% and their melting temperatures were within 5 °C of each other. [8] [9] [10] In 2014, a threshold of 79% similarity has been suggested to separate bacterial subspecies. [11]
The use of (Z)-7-dodecen-1-yl acetate as a sex pheromone by the Asian elephant (Elephas maximus) and by more than 100 species of Lepidoptera. The biosynthesis of plant hormones such as gibberellin and abscisic acid by different biochemical pathways in plants and fungi. [255] [256]
Similarity measures play a crucial role in many clustering techniques, as they are used to determine how closely related two data points are and whether they should be grouped together in the same cluster. A similarity measure can take many different forms depending on the type of data being clustered and the specific problem being solved.
The term "percent homology" is often used to mean "sequence similarity”, that is the percentage of identical residues (percent identity), or the percentage of residues conserved with similar physicochemical properties (percent similarity), e.g. leucine and isoleucine, is usually used to "quantify the homology."
An evolutionary grade is a group of species united by morphological or physiological traits, that has given rise to another group that has major differences from the ancestral group's condition, and is thus not considered part of the ancestral group, while still having enough similarities that we can group them under the same clade.
The pattern of similarity was interpreted as part of the static great chain of being through the mediaeval and early modern periods: it was not then seen as implying evolutionary change. In the German Naturphilosophie tradition, homology was of special interest as demonstrating unity in nature.
An operational taxonomic unit (OTU) is an operational definition used to classify groups of closely related individuals.The term was originally introduced in 1963 by Robert R. Sokal and Peter H. A. Sneath in the context of numerical taxonomy, where an "operational taxonomic unit" is simply the group of organisms currently being studied. [1]
Homoplasy, in biology and phylogenetics, is the term used to describe a feature that has been gained or lost independently in separate lineages over the course of evolution. This is different from homology , which is the term used to characterize the similarity of features that can be parsimoniously explained by common ancestry . [ 1 ]