Conference Paper
The primacy of the genotype
Wilkens, H
Record Number:
4266
Year:
2019
Journal:
AIM 2019
Pages:
15
Abstract:
Biologically functionless traits show high variability, which results from neutral deleterious
mutations no longer eliminated by natural selection. They get phenotypically manifest and
accumulate until these traits are rudimentary or even lost. The random genetic basis of regressive
evolution is in accordance with Nei´s “Neutral Theory of Molecular Evolution”, which applies to
the molecular level. Such processes are particularly conspicuous in species living in continuous
darkness, where all traits depending on the information of light, like eyes, pigmentation, visually
released aggressive behaviour, negative phototaxis as well as several peripheral outcomes of
circadian rhythmicity, are useless and get reduced. In compensation, constructive traits like taste,
olfaction or the lateral line sense are improved by selection. These do not show increased
variability, because natural selection usually acts to preserve functional capability of a trait.
Regressive and constructive traits inherit independently proving that the rudimentation process is
not driven by pleiotropic linkage between them. All these traits exhibit unproportional epistatic
gene effects and are submitted to mosaic evolution. Variability is essential for evolution in general
and is also found during the initial phase of adaptive radiation due to selection relaxing because
of missing competition.
Times Cited:
1
Relevent Species: