منابع مشابه
Molecular clocks and geological dates: cytochrome b of Anolis extremus substantially contradicts dating of Barbados emergence.
Even though molecular clocks vary in rate to some extent, they are widely used and very important in a range of evolutionary studies, not least in interpreting cause and colonization in phylogeography. Evolutionists may use island age and emergence to give the earliest possible date for colonization by a species and hence give the lower limit in a molecular clock calibration. The geology of the...
متن کاملCircadian Biology: Clocks within Clocks
A small cluster of approximately 20,000 neurons in the ventral hypothalamus provide the body with key time-keeping signals and drive circadian rhythms. This circadian clock exhibits surprisingly complex substructures, with inputs from the retina, and outputs to other brain structures. Rather little is known of the neurotransmitters involved, or their regulation.
متن کاملHuygens's Clocks Author(s): Huygens's Clocks
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متن کاملClocks within clocks: timing by coincidence detection
The many existent models of timing rely on vastly different mechanisms to track temporal information. Here we examine these differences, and identify coincidence detection in its most general form as a common mechanism that many apparently different timing models share, as well as a common mechanism of biological circadian, millisecond and interval timing. This view predicts that timing by coin...
متن کاملMolecular clocks.
A convenient and precise mass spectrometric method for measurement of the deamidation rates of glutaminyl and asparaginyl residues in peptides and proteins has been developed; the rates of deamidation of 306 asparaginyl sequences in model peptides at pH 7.4, 37.0 degrees C, 0.15 M Tris.HCl buffer have been determined; a library of 913 amide-containing peptides for use by other investigators in ...
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ژورنال
عنوان ژورنال: Nature
سال: 1976
ISSN: 0028-0836,1476-4687
DOI: 10.1038/260205b0