News tagged with natural selection
Related topics: genes , proceedings of the national academy of sciences , evolution , genome
Natural selection is the process by which heritable traits that make it more likely for an organism to survive and successfully reproduce become more common in a population over successive generations. It is a key mechanism of evolution.
The natural genetic variation within a population of organisms means that some individuals will survive and reproduce more successfully than others in their current environment. For example, the peppered moth exists in both light and dark colors in the United Kingdom, but during the industrial revolution many of the trees on which the moths rested became blackened by soot, giving the dark-colored moths an advantage in hiding from predators. This gave dark-colored moths a better chance of surviving to produce dark-colored offspring, and in just a few generations the majority of the moths were dark. Factors which affect reproductive success are also important, an issue which Charles Darwin developed in his ideas on sexual selection.
Natural selection acts on the phenotype, or the observable characteristics of an organism, but the genetic (heritable) basis of any phenotype which gives a reproductive advantage will increase in frequency over the following generations (see allele frequency). Over time, this process can result in adaptations that specialize organisms for particular ecological niches and may eventually result in the emergence of new species. In other words, natural selection is an important process (though not the only process) by which evolution takes place within a population of organisms.
Natural selection is one of the cornerstones of modern biology. The term was introduced by Darwin in his groundbreaking 1859 book On the Origin of Species, in which natural selection was described by analogy to artificial selection, a process by which animals with traits considered desirable by human breeders are systematically favored for reproduction. The concept of natural selection was originally developed in the absence of a valid theory of heredity; at the time of Darwin's writing, nothing was known of modern genetics. The union of traditional Darwinian evolution with subsequent discoveries in classical and molecular genetics is termed the modern evolutionary synthesis. Natural selection remains the primary explanation for adaptive evolution.
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Researchers from Queen Mary, University of London have led the largest sequencing study of human disease to date, investigating the genetic basis of six autoimmune diseases.
Genetics 5 hours ago | not rated yet | 0 |
If Pygmies are known for one trait, it is their short stature: Pygmy men stand just 4'11" on average. But the reason why these groups are so short and neighboring groups are not remains unclear. Scientists have proposed various ...
Genetics Apr 26, 2012 | 4.5 / 5 (2) | 0 |
The longstanding mystery of how selective hearing works how people can tune in to a single speaker while tuning out their crowded, noisy environs is solved this week in the journal Nature by two ...
Neuroscience Apr 18, 2012 | 3.7 / 5 (3) | 0 |
When timing is everything: Research says beneficial mutations need specific circumstances to win out
When it comes to the sort of beneficial mutations that drive natural selection, there's new evidence that, evolutionarily speaking, timing is everything.
Genetics Mar 20, 2013 | 5 / 5 (1) | 4 |
When Charles Darwin first sketched how species evolved by natural selection, he drew what looked like a tree. The diagram started at a central point with a common ancestor, then the lines spread apart as ...
Genetics Jan 09, 2013 | 4 / 5 (6) | 1 |
According to researchers at Moffitt Cancer Center, cancer is subject to the evolutionary processes laid out by Charles Darwin in his concept of natural selection. Natural selection was the process identified by Darwin by ...
Cancer Jun 21, 2012 | not rated yet | 1 |
In new research published on March 21, 2013 in the online issue of The American Journal of Human Genetics, researchers from Brigham and Women's Hospital (BWH) demonstrate that some variants in our genes that contribute to a p ...
Genetics Mar 21, 2013 | not rated yet | 0
Epigenetics – how gene expression is regulated by temporary switches, called epi-marks – appears to be a critical and overlooked factor contributing to the long-standing puzzle of why homosexuality occurs.
Genetics Dec 11, 2012 | 3.5 / 5 (4) | 0
Human genes are preferentially encoded by codons that are less likely to be mistranscribed (or "misread") into a STOP codon. This finding by Brian Cusack and colleagues from the Max Planck Institute for Molecular Genetics ...
Genetics Oct 13, 2011 | 5 / 5 (1) | 0
Over 500 billion cells in our bodies will be replaced daily, yet natural selection has enabled us to develop defenses against the cellular mutations which could cause cancer. It is this relationship between evolution and ...
Cancer Jan 22, 2013 | not rated yet | 0