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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how can a recessive allele become represented in a significant number of individuals in a population

Darwin believed that individuals that are poorly adapted to their environment are less likely to survive and reproduce. This means that their genes are less likely to be passed to the next generation. ...
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Is it possible to Breed an Animal to have more Females than Males?

Minute Earth talked about environmental factors that cause animals and humans to have more male or female children: https://www.youtube.com/watch?v=3IaYhG11ckA Presuming that is accurate, I was ...
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Tumor-suppression, cell differentiation, and apoptosis: How do macroevolutionists justify dismissing such strong evidence for intelligent design? [closed]

Consider the 20 kilobase TP53 gene named for its massive initially-believed 53 kilodalton protein product (later found to be 43 kilodaltons - see https://en.wikipedia.org/wiki/TP53). Something that ...
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Has human evolution currently stopped? [duplicate]

Due to the advent of social networking and dating sites, it is now possible for almost anyone to find a potential mate. Therefore, there is not as much of a pressure based on physical characteristics ...
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How is “selection” best defined?

There is natural selection but there is also sexual selection which some regard as a category of natural selection. There is also artificial selection (by humans). The question is, what is a most ...
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What evolutionary reason is there for hemolytic disease?

Nowawadays we have methods which allow us to overcome hemolytic disease of newborn or to prevent it to onset. The Rh or Kell conflict, but how is it possible that it is present? Why it haven't ...
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Can the value of heritability be greater than 1?

Heritability defined as genetic variance divided by total variance seems to be bounded between 0 and 1. However, I see a way of calculating heritability on this page (http://www.radford.edu/~rsheehy/...
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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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identification of purposeful (engineered) genetic changes vs. random mutations

Okay, first - I'm not a proponent of intelligent design. I do not think it's a valid scientific theory (it has no mechanism of change/design). Second, I could be wildly off on what I think I know, in ...
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What are the 2 general systems to understand the whole natural world? [closed]

In Graham Bell's book Selection, it's written: To some it may be a cause of regret that the natural world cannot be understood in terms of a single set of rules and laws, but at least, so far as ...
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How can we decide at which level does natural selection apply? [closed]

Here is a passage from The Selfish Gene If selection goes on between groups within species, and between species, why should it not also go on between larger groupings? Species are grouped into ...
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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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phylogenetics and substitution ratios for positive selection [closed]

So very new to phylogenetics!. I've been scrambling and reading so much to get this done!!. I would like to see if one or more of the sequences I have (from a gene family) are under positive ...
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How does natural selection process escape from local optima? [closed]

How does natural selection process escape from local optima towards global optimum in a fitness landscape during evolution?
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Is this a counter-example to Darwin's theory of evolution? [closed]

Somewhere I read following paragraphs giving one counter-example to Darwin's theory of evolution. (By the way, I am a physicist and not a biologist, but I am interested in this field.) Do these ...
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How to distinguish between a genetic bottleneck and directional selection?

Genetic bottlenecks and directional selection should have relatively similar genetic signals: reduced heterozygosity and greater genetic divergence (Fst?) in contemporary populations compared to the ...
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Why might the chirality of gastopods be dominantly dextral?

This wikipedia page on gastropods provides a definition of chirality, and briefly describes the genetic mechanisms behind why a shell is wound left (sinistral) or right (dextral) handed. It also ...
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Is hunting animals, crafting and attacking/defending from enemies intellectually equivalent to learning quantum physics? [closed]

Our brains were shaped after natural selection. Which means that, as long as we were being affected by it, our brains were changing, evolving. Once we stepped out of nature and stopped being targets ...
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What is meant by `individuals do not evolve, populations do`?

My university professor stated that "individuals do not evolve, populations do". But aren't populations made up of individuals? That's like saying when a compound changes in stability, none of the ...
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Meaning of phrase with term, “intelligent design” [closed]

I am am mathematician, kindly correct me, If I am wrong somewhere. I am reading a book titled "Sapiens " by Noah Harari. He says Organism are increasingly shaped by intelligent design rather than ...
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How to determine whether changes of an allele's frequency are due to genetic drift or selection?

Given that both natural/artifical selection and genetic drift are evolutionary mechanisms that influence how allele frequencies shift in a population: Are there ways to determine whether a frequency ...
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What is a typical value of the selection coefficient s?

I am trying to gain an understanding of the real world effects of natural selection from the equations, especially comparing it with drift. However I have been unable to find any examples which give ...
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Fst Differences Between Mature Trees and Seeds

For a single co-dominant locus in two populations of blue oak, I am given genotype frequency data (genotypes are AA, AB, BB) for adult trees (at least 150 years old) in both populations (pop 1 and pop ...
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Boys born in excess - how can the nature draw from non-natural distributions?

The probability of a newborn baby to be a boy is not exactly 50% but a bit more. I have been given the explanation that it is because boys act more self-destructive during the early ages and so the ...
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Can growth rate be used as an indicator of fitness in fish populations?

I would like to calculate selection gradients in order to gain insight into the strength and type of selection influencing my study population. (see here for review. http://jgking.web.unc.edu/files/...
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layman inquiry into mechanics of evolution [closed]

Consider a species. Without some particular mutation, its members have quality A. Suppose that quality B is better for the survival of any individual member of the species. If one member possesses ...
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Is there a word for the assumption that a sufficiently complex and refined organ must be the result of natural selection on a large time scale?

Is there a term for the valid assumption that a sufficiently complex and refined organ must be the result of natural selection on a large time scale? Example: A biologist exists in a world where ...
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Why haven't modern grass based crops overrun wild grasses?

Modern grass based crops are significantly superior to wild grasses, they grow faster, are stronger stemmed, have larger leaves and higher seed yields in terms of individual seed size, giving ...
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What is the difference between natural selection and adaptation?

From what I've read it seems that the only actual difference is that creationists use adaptation and people who believe in evolution use natural selection. But otherwise, from my understanding, the ...
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Ecological specialization and relative abundance

I am reading Evolution in Changing Environments by R. Levin but have a hard time. Claim At page 25, Levin says as a conclusion The more efficient a caste at meeting the contingency for which it ...
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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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do game animals have poor eyesight?

I have been watching some bow hunting videos on youtube. When hunting with a bow, the hunter needs to get really close to the animal, sometimes less than 10 meters. It seems to me implicitly, and ...
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What model of epistasis best fit the reality?

In theoretical population genetics, it is very common to have to assume a model of epistatic interaction. The two most common models are the additive model and the multiplicative model. Additive ...
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Determination of genes to be modified in epigenetics [closed]

It seems that during reproduction particular genes are targeted for modification (mutation, deletion, insertion, etc.) given environmental inputs of either or both of the parents. If a creature was ...
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Why do many people seem to prefer unhealthy compared to healthy foods?

I don't have any concrete statistics on this but many of us seem to love the taste of food that is unhealthy for us. Over the centuries, wouldn't it have been a non negligible advantage to those who ...
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Evolution of parasite into ideal parasite [duplicate]

An ideal parasite is a parasite which thrives within a host without harming it (according to my NCERT textbook). Then, quite obviously, why hasn't that happened yet? I mean, natural selection can ...
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Does the species of snake that eats Amphidromous inversus have chiral dimorphism?

From what I read at Schilthuizen and Davison (2005), Amphidromous inversus is a species of snail that occurs in 2 forms that are nearly mirror images of each other occurring in nearly equal ...
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How to name a case of convergent evolution where the same mutation is involved in both lineages?

Definition of Convergent evolution - from Wikipedia > Convergent Evolution Convergent evolution is the independent evolution of similar features in species of different lineages. Convergent ...
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Is there an evolutionary basis for why women mature faster than men?

Females develop both physically and mentally earlier than males do. For example; females start puberty at an earlier age than males, and females brains mature more quickly than male brains. Girls ...
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Are there examples of selection on males influencing female phenotypes?

I've been studying selection on female body color in a sexually dimorphic species and am intrigued by the possibility that selection on males, whether it be through sexual or natural selection, may ...
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Why do heterozygous individuals have increased resistance to malaria?

I am aware that there is such a thing called heterozygous advantage, which is due to the presence of a certain single allele, and that an example of this could be with "sickle-cell anemia". I am ...
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Have scientists ever produce a new species in laboratory by means of natural selection?

I was wondering, if scientists ever produce a more complex species from a less complex species by means of natural selection? I imagine something like, bacteria which can't photosynthesis and oxygen (...
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Is there a formal definition of signature of natural selection?

I’ve searched for a definition of signature of natural selection. Unfortunately, I haven’t found any formal definition of it. The signature of positive selection ...
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Difference/similarity between adaptive radiation and species divergence?

I've been reading various answers on different sites but I still don't know whether adaptive radiation and species divergence are different or similar. My questions: 1) On some sites, it says that ...
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Why even if all requirements for natural selection are met, it may not happen?

In the book written by John Endler Natural Selection in the Wild p. 4 it says that even if condition a, b and c are met, evolution by natural selection might occur, [...] , but not necessarily, [...
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Games with non-uniform interaction rates

Background: Many models in evolutionary game theory assume uniform interaction rates. For instance, consider the $2\times 2$ game: \begin{array}{l c c} & A & B \\ A & a & b \\ ...
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Replicator equation for mixed strategies?

The the replicator equation is usually defined for pure strategies. More specifically, the replicator eqn for $n$ strategies is given by: \begin{equation} \dot x_{i} = x_{i} \left( \sum_{j=1}^{n} a_{...
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Do scouting bees get to pass their genes to offspring?

Let's say the food-scouting behavior of scouting bees are enhanced when some particular alleles are expressed. By natural selection, the allele frequency for that "good" allele should increase because ...
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How does the modern synthesis theory explain the evolution of birds from dinosaurs? [closed]

The theory of evolution claims that birds evolved from dinosaurs only by mutation, genetic drift, migration and natural selection. However, it seems to me that wings were not selectively advantageous ...
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How does Darwinian Evolution work?

Let me explain... A friend and I read some articles, part of a Biology book, and watched a video on evolution. We then tried to explain what Evolution is to each other. My friend said that Natural ...