Questions tagged [natural-selection]

A mechanism of evolution that leads to non-random spread of genes due to the effect that genes have on reproductive success.

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What determines whether a trait brought out through sexual selection is transmitted only to offspring of the same sex or of both sexes?

First of all, let me apologize for my amateurishness. I have no background in biology. Please bear with me. My question relates to sexual selection, or specifically its most prominent manifestations: ...
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What is the difference between effective and efficient selection?

I always thought of the efficiency of natural selection in the context of molecular evolution. I.e. that linked selection and smaller population size cause less efficient selection. It took me a while ...
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Balancing selection vs introgression?

Balancing selection can maintain polymorphisms in natural populations for extended periods of evolutionary time. However, in this paper, Dannemann et al. 2016 identify three archaic haplotypes in the ...
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Why are fairyflies so small?

The Mymaridae are the smallest insects. This video explains their numerous adaptations to being as small as 140 microns yet still complex, such as smaller cells with as little cytoplasm as possible, ...
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Which processes in the human body depend on natural selection among cells?

Are there processes in the human body which occur via natural selection among cells? Could anyone provide examples? E.g. when tissues are conditioned to be stronger, such as a rock climber's skin ...
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How is the possibility of beneficial mutations ensured in the genome?

To ensure natural selection and variability, the genome must have a structure in which the occurrence of beneficial mutations has a high enough probability. But how is this ensured? The space of ...
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higher-order evolutionary adaptations

Most adaptations are what I'd call first-order. Cats evolve better eyesight; redwoods evolve to grow taller; male cardinals evolve attractive bright feathers. All of these changes were selected for ...
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Visualizing selection's effect on a population with a fitness landscape in R

I'm trying to write a script to demonstrate the effect of selection in a population. The problem that I have is that it is not realistic in the sense that not only the mean would change for ...
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Nonlinear (Quadratic) selection gradients formula

Under scenarios of stabilizing or disruptive selection, we can add a quadratic component to our model of phenotype and fitness like so. Specifically, I am not clear on where the 1/2 comes from nor do ...
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Is the suicide of a moribund individual to be considered group selection?

When a moribund individual commits suicide (e.g., Refardt, Bergmiller & Kummerli, 2013; http://rspb.royalsocietypublishing.org/content/royprsb/280/1759/20123035.full.pdf), is this to be considered ...
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How can normalizing selection (stabilizing selection) be involved in speciation?

In Mayr's book What Evolution Is, he discusses about normalizing selection in rapidly evolving lineages. "However, normalizing selection is equally active in rapidly evolving lineages." ...
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Can a trait be too successful? Wouldn't overwhelmingly successful traits limit variability, which is one of the requirements of NS? [closed]

Can a trait be too successful? Wouldn't an overwhelmingly successful trait soon limit the gene pool, and if so, how would the process of natural selection react to that? If an individual is born ...
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What is the relationship between radiation and evolution?

There is always a certain amount of background radiation present, for example due to ionizing radiation from the sun and other stars. Also certain materials like granite may emit relatively large ...
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Is it possible there were multiple origins of life? And, if so, why did the one which became the common ancestor between all organisms prevail?

I have learned that all currently-living organisms come from a common ancestor, which I theoretically understand. However, my professor in a class mentioned that there is a chance that there were ...
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Population Genetics Using WGS: How do I know when I have enough individuals?

I am having a difficult time finding information about a minimum threshold for number of individuals to use in wgs pop gen analyses. Are there software or formulas/theory available to determine what ...
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Evolution at a glacial pace: how does it work? [duplicate]

Some trees are very long-lived, such as the Great Basin Bristlecone Pine and the Giant Sequoia (up to 4,800 years old). How does natural selection and evolution affect such long-lived organisms? ...
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What is the impact of selection on orthologous and paralogous genes? How would this impact differ in different regions of protein coding genes?

Since paralogs increase the size of the genome and provide more opportunity for the evolution of novel characteristics, would they be more prone to selection?
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When telomere length is measured, is the method performed on a collection of cells yielding an average?

What are the methods used in measuring telomeres in human or animal subjects? Can it be done on an individual cell? Has the following concern been raised and addressed before: What if there exists a ...
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How did migrations evolve?

Disclaimer: I know nearly nothing about biology. I was wondering how did the migratory behaviour of birds evolve. Assuming that evolution/natural selection works slowly and gradually (at least most of ...
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Is social anxiety a part of human gene pool and caused by natural selection?

I'm reading a book called 'Why Buddhism Is True' and I'm not sure I understand author's point regarding social anxiety and natural selection: Our ancestral environment didn’t feature cocktail parties,...
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How frequent are selective sweeps?

Introduction Selective sweep is the most famous genetic signature of selection. We know of a number of classical examples of selective sweeps, some of them in humans. See the classical example of the ...
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Do beneficial viruses exist? If so, what examples are there?

Typically, people call viruses some kind of organic compounds that cannot reproduce autonomously and which lower the fitness of their hosts. Even the word "virus" means "venom" in Latin. But from the ...
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Why might long telomeres be selected for in laboratory mice?

In a recent episode of The Portal, Eric Weinstein sits down with his brother Bret Weinstein to discuss Bret's Reserve-Capacity Hypothesis. It's an incredible story of scientific discovery and and ...
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Is natural selection actually random?

In the Theory of Evolution, two main factors take place: One is random, which are the different mutations that organisms' DNA suffer. This process adds genetic variability to a given population. The ...
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Why is selection less effective in small populations than in larger?

I can understand that the genetic drift has a higher impact on smaller populations, but what does it mean for the selection to be less effective in small populations than higher?
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Do any known viruses contain "junk" or parasitic genomic information?

After reading about so-called "mystery proteins" in this excellent summary of the coronavirus genome (and acknowledging that the "mystery" simply reflects our lack of knowledge about a very new virus),...
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Are there real world examples of one way isolation between two populations?

I know that for two populations A and B, there are situations in which there is a two way exchange of individuals between the populations, and there are situations in which there is no exchange of ...
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Does epigenetics suggest there is at least some element of truth to Lamarckism?

I am not a biologist. But googling "epigenetics lamarck", I find many different opinions: For: Lamarck rises from his grave, Epigenetics: Lamarck’s Revenge?, Darwin’s theory ... is incomplete without ...
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Is natural selection a force?

I often hear that natural selection, or simply, selection is a "force". e.g.: the forces of directional selection on correlated life history characters, and an adaptive topography ...
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Clarification regarding a statement in "The Selfish Gene" by Richard Dawkins

In the third chapter of The Selfish Gene: Immortal coils, Dr.Dawkins makes the following statement while arguing for the case that ultimately "the gene" as he defines it is the unit of natural ...
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What is the difference between disruptive, divergent and diversifying selection?

In our lab meeting we were chatting about divergent selection. I was confused at some point because I wasn't sure what was the meaning of this work in comparison to diversifying/disruptive and other ...
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Exact terminology of natural selection

You don't need to explain to me what the theory of evolution is, or how it works. This question is purely about what exact meaning the word "natural selection" is ascribed to. There seem to be ...
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Are mosquitoes attracted to blue lights in particular?

I've been confronting the fact since childhood that mosquitoes are attracted to lights, especially blue lights. Now I know that all insects including mosquitoes are attracted to bright light but I ...
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What is the difference between the evolution of fins in whales and fish?

For a homework assignment I received the following question: Which statement best explains the evolution of fins in whales and fish? a. The common ancestor of whales and fish possessed genes for ...
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Why are smaller mammals more prone to cancer and tumors

especially rats and mice usually develop cancer and tumors very fast, reducing their life expectancy. From an evolutionary point of view, how come that these mammals are so prone to cancer and tumors ...
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Does technological developments terminate the evolution of human species? [duplicate]

One of the most agreed upon mechanism for evolution is natural selection.Changing environmental conditions necessities development of variations that enable the survival of that particular species....
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Does natural selection still increase biological complexity?

I recently read The Selfish Gene by Richard Dawkins, which I found very interesting. In one of the last chapters, he gives multiple possible explanations to the question "Why did natural selection ...
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Is the frequency at which a species mutate affected by natural selection? [duplicate]

As per natural selection, is it safe to assume that some species will have it genetically encoded so that they produce a certain 'perfect' rate of mutation so that they can adapt to an environment ...
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How does natural selection explain sexual display?

As I understand it, animals sometimes grow more vibrant colors, bigger feathers, elaborate dances, build shiny nests, all to impress the other sex. However, these are all superfluous to survival -- ...
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Evolution of recurrent laryngeal nerve in a giraffe [closed]

Do natural selection and survival of the fittest explain the divergent length of the recurrent laryngeal nerve...centimeters in the human, 15 feet in the giraffe?
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Is evolution always unidirectional?

Is it possible, at least in theory, for a species to evolve into another species and then evolve back into the first species?
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What are the implications/predictions of the selfish gene theory?

Are there any testable predictions or implications of the selfish gene theory? Or it is just interesting interpretation of the observations/experimental data? If this theory is not falsifiable and ...
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Examples of animals who 'forget' their offspring

Occasionally on the news I read about young children dying in hot cars on a sunny day. Usually the article reports that the parent(s) 'forgot' about their children still being in the car. Obviously ...
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Who were the first authors to talk about local adaptation?

I was curious to read about what Darwin had to say about the existance of locally adapted subpopulations. I discovered to my surprise that the expressions and terms "local adaptation", "spatial ...
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What is the relationship between r/K strategy and filial infanticides?

In other words, is the frequency of killing one's own offspring among species dependent on their location on the r/K strategy spectrum?
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Why can't geese regurgitate food?

I saw this harrowing video on how barnacle goslings have to jump off very high cliffs because the parent's can't feed them. The death rate seems high. Why did natural selection come to favor jumping ...
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Discrete vs Continuous Replicator Dynamics

The replicator eqn in the case of discrete non-overlapping generations and asexual reproduction is given by the discrete replicator eqn: $$x_i(t+1) = x_i (t)\frac{f_i(t)}{\bar f (t)}$$ where $x_i$ is ...
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Why would low complexity regions be linked with relaxed selection?

I'm reading a text (Wagner, 2007) on identifying positive selection. In the paper, the author says that low complexity regions are known to be associated with the relaxed selection. I'm trying to ...
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Is variation a result of Evolution?

We know that the DNA copying mechanism that replicates DNA during cellular division is not 100% accurate and the resultant errors are the source of variation in the members of a population. At the ...
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Sharks, alligators and Gould's "random walk" theory

I was thinking about Stephen Jay Gould's view on evolution as pure "random walk" / Drunkard's Walk, increasing or decreasing complexity in basically random fashion, just limited by death if an ...

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