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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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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Models of evolution by positive versus negative selection

I am making a program for simulating natural selection. Now, I have discovered an interesting difference between positive selection and negative selection. Positive selection occurs when the ...
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Do technological developments terminate the evolution of human species? [duplicate]

One of the most agreed upon mechanisms for evolution is natural selection. Changing environmental conditions necessitates development of variations that enable the survival of that particular species. ...
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Intelligence without natural selection?

Natural selection is not the only driving force of evolution. There are other mechanisms such as genetic drift, mutations, gene flow, etc... To what extent can these different mechanisms (which don't ...
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Is Natural Selection like a Copy Editor?

I am stuck on a Homework Question. It says: Evaluate the following statement: “Natural selection works like a copy editor; it works only with what is already present in a population.” (Note: ...
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Impact of Natural Selection on Population Size [closed]

I have conducted a lab with my IB Biology 11 class, regarding changes in allele frequencies within generations overseeing the natural selection of an advantageous phenotype. We were looking to ...
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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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Fisher's Geometric Model for Dummies

Fisher's geometric model is still today one of the most important and fundamental model in evolutionary biology but it seems to me that most student in evolutionary biology don't really understand it (...
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What percentage of the fitness variance is explained by the 'n'- most important loci?

Introduction Standard models in population genetics look up at the evolution of few loci which impact fitness. The variance in fitness is determined by the genetic variance and the environmental ...
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Ways to distinguish between purifying selection and selective sweep

When looking a population genomic data, regions of low diversity (lower than expected; such as in a region of high recombination) can indicate either purifying selection of deleterious mutations or a ...
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Given that "genetic drift" can happen, why is searching for an adaptive explanation for traits considered an important scientific question?

I saw today on Wikenigma (a wiki for open questions in science) that there are many competing explanations for why zebra stripes are evolutionarily adaptive, and there is no consensus on which one(s) ...
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What are Some Classical Examples of Local Adaptation?

Question Can you please give a list of classical (textbook) examples of local adaptations? How to answer Examples don't necessarily need to include what evidence supports this specific example of ...
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What is "Correlation of growth" according to Darwin and was he correct about it according to modern science?

What are the views that modern biologist have on Correlation of growth? I need some clarification on statement that I'm gonna mention below as well that is it reason to that as mentioned here: "...
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Would the environmental pressures imposed by humans make the housefly of today significantly harder to swat than their ancestors of 1000 years ago?

For context, I am primarily referring to Musca domestica. Recently the thought occurred to me that due to short life cycle of the common housefly, and due to the fact that such flies have interacted ...
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How to get an adaptive landscape from a fitness function?

In Schluter (2000), it is mentioned that one can convert a fitness function (see image (a)) to an adaptive landscape (see (b) and (c)). The key is to calculate the mean phenotype of a population and ...
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What mammalian species has the greatest relative variance in adult size?

The smallest adult chihuahuas weigh about 2 kg, and the largest adult English Mastiffs are around 104 kg, making them 52 times larger by weight. Of course, this enormous variance is the result of ...
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Balancing selection vs introgression? [closed]

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 do some bad traits evolve, and good ones don't?

If a trait would be advantageous to an organism then why hasn't it evolved yet? Conversely, if a trait is not advantageous or mildly disadvantageous, why does it exist? In other words why does ...
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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 academic ...
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How does natural selection interacts with sustained mask use?

At leasts in some European countries, the number of respiratory (non-covid) infectious diseases on children this term is higher than last year and similar to pre-pandemic years in spite of social ...
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Why is "mutual search" of some disadvantage/loss of power? (in Darwin's The Descent of Man)

I read a book "The Descent of Man" from Charles Darwin. What is the reason for the following statement? "It would be no advantage and some loss of power if both sexes were mutually to ...
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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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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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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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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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