Psychology & Psychiatry

Want to save the planet? Stop trying to be its friend

A new theory suggests that we think of our relationship with the environment like a social exchange, leading to the belief that 'environmentally friendly' behavior can compensate for 'harmful' behavior.

Genetics

Evolution of psychiatric disorders and human personality traits

How and why human-unique characteristics such as highly social behavior, languages and complex culture have evolved is a long-standing question. A research team led by Tohoku University in Japan has revealed the evolution ...

Psychology & Psychiatry

Psychological link between conspiracy theories and creationism

Ask a three-year-old why they think it's raining, and she may say "because the flowers are thirsty." Her brother might also tell you that trees have leaves to provide shade for people and animals. These are instances of teleological ...

Genetics

New perspective on tumor genome evolution

An interdisciplinary team of scientists at the Centre for Genomic Regulation in Barcelona, Spain, deepens the understanding of tumor genome evolution and suggests negative selection acting on cancer-essential genes plays ...

Genetics

The dark side of our genes – healthy aging in modern times

The transition to modernity, largely driven by the Industrial Revolution, provided us with easier access to food and clean water, with antibiotics, vaccines, and modern medicine. Yet modernity did not just bring fewer infectious ...

Genetics

Natural selection still at work in humans

Evolution has shaped the human race, with University of Queensland researchers finding signatures of natural selection in the genome that influence traits associated with fertility and heart function.

Genetics

Quiescent cells also mutate

For almost a hundred years, geneticists have believed that the more a cell divides the more mutations it acquires. However, research by scientists at the Institut Pasteur shows that quiescent cells, which do not divide, also ...

Psychology & Psychiatry

When it comes to our brains, there's no such thing as normal

There's nothing wrong with being a little weird. Because we think of psychological disorders on a continuum, we may worry when our own ways of thinking and behaving don't match up with our idealized notion of health. But ...

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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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