Molecular Clock

The molecular clock (based on the molecular clock hypothesis (MCH)) is a technique in molecular evolution that uses fossil constraints and rates of molecular change to deduce the time in geologic history when two species or other taxa diverged. It is used to estimate the time of occurrence of events called speciation or radiation. The molecular data used for such calculations is usually nucleotide sequences for DNA or amino acid sequences for proteins. It is sometimes called a gene clock or evolutionary clock.

Read more about Molecular ClockEarly Discovery and Genetic Equidistance, Relationship With Neutral Theory, Calibration, Non-constant Rate of Molecular Clock, Methods, Uses

Other articles related to "molecular clock, molecular, clock":

Molecular Clock - Uses
... The molecular clock technique is an important tool in molecular systematics, the use of molecular genetics information to determine the correct scientific classification of organisms or to ... Knowledge of approximately-constant rate of molecular evolution in particular sets of lineages also facilitates establishing the dates of phylogenetic events, including those not documented by fossils, such ...
History Of Molecular Evolution - The "molecular Wars"
... From the early 1960s, molecular biology was increasingly seen as a threat to the traditional core of evolutionary biology ... and 1940s—were extremely skeptical of molecular approaches, especially when it came to the connection (or lack thereof) to natural selection ... Molecular evolution in general—and the molecular clock in particular—offered little basis for exploring evolutionary causation ...
PER1 - Function - Feedback Mechanism
... negative feedback mechanism, which creates a cell autonomous molecular clock ... Heterodimer CLOCK-BMAL1 activates E-box elements present in the Per1 promoter, as well activating the E box promoters of other components of the molecular clock such as PER2 ... a more gradual increase in phosphorylated PER, and an additional control over the period of the molecular clock ...
Toba Catastrophe Theory - Genetic Bottleneck Theory - Genetic Bottlenecks Related To The Human Population
... On the other hand, in 2000, a Molecular Biology and Evolution paper suggested a transplanting model or a 'long bottleneck' to account for the limited ... Late Stone Age Takahata (1999) was the first molecular anthropologist to point out that conclusions drawn from single locus studies suffer from the large randomness of the fixation process ... This suggests a SNP rate inaccuracy in the Y-chromosomal and/or mtDNA molecular clock ...
Neutral Theory Of Molecular Evolution - Overview
... the genomes of existing species, the vast majority of molecular differences are selectively "neutral", i.e ... the molecular changes represented by these differences do not influence the fitness of the individual organism ... Thus the neutral theory provides a rationale for the molecular clock, although the discovery of a molecular clock predates neutral theory ...

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