Ancient genomes reveal immunity adaptation in early farmers

Research from the Francis Crick Institute published today in Current Biology has revealed that diversity in genes coding for immunity may have facilitated adaptation to farming lifestyles in prehistoric periods.

Diseases, Conditions, Syndromes

Modeling the COVID-19 roller coaster

First it was alpha. Then delta. Now omicron and its alphabet soup of subvariants. In the three years since the coronavirus pandemic started, every few months or so a new strain seems to go around, only to be outdone by the ...

Diseases, Conditions, Syndromes

New receptor 'decoy' drug neutralizes COVID-19 virus and its variants

Scientists at Dana-Farber Cancer Institute have developed a drug that potently neutralizes SARS-CoV-2, the COVID-19 coronavirus, and is equally effective against the Omicron variant and every other tested variant. The drug ...

Diseases, Conditions, Syndromes

Using AI to predict COVID surges

A team of researchers recently developed an artificial intelligence model that can predict which coronavirus variants will likely dominate and cause surges. The work was led by Jacob Lemieux, an assistant professor of medicine ...

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Natural selection

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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