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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736 views

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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How to statistically test the predictability of evolution? [closed]

Can anyone recommend me an experimental study which tries to test the predictability of evolution? The closest works I found are the studies of fluctuation tests (f.e. classical study of Luria & ...
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Will moths evolve to become blue if we paint walls in blue?

I know dark moths are more frequent than white moths when the environment is full of dirty (dark) walls/trees; it is a consequence of natural selection. Will moths evolve to become blue if walls/trees ...
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Who was the first to coin the terms of soft and hard selection?

Soft and hard selection are sometimes used with different definitions. I have been told that at first place hard and soft selection has been defined in the following way: soft selection: Each deme ...
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The replicator equation vs the Lotka-Volterra equation

Background The replicator equation with $n$ strategies is given by the differential equation: \begin{equation} \dot x_{i} = x_{i} \left( \sum_{j=1}^{n} a_{ij}x_{j} - \phi \right) \qquad i = 1, \...
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What is a selective constraint?

I encountered the term selective constraint in Huber et al. 2015, page 4 (last paragraph) in: If invariable sites are included in the analysis, then both the methods of Kim and Stephan (2002)...
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Variance in reproductive success and effective population size

Background The effective population size $N_e$ is the size of the Wright-Fisher population that experience the same amount of drift than the population under consideration. The higher the variance ...
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How did the double circulatory system evolve from the single circulatory system

I already learned how the mammal circulatory system (double circulatory system) evolved from the reptilian circulatory system. How did natural selection evolve the reptilian circulatory system and the ...
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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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Why didn't humans evolve to reproduce identical twins all the time?

According to the selfish gene theory, it seems like because identical twins sometimes get produced, a mutation to a gene that says, "if you have an identical twin, be fully altruistic towards them" ...
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Is our genome decaying (see “Genetic Entropy”), and, if so, is this evidence for our genome being “young”?

In the book Genetic Entropy & the Mystery of the Genome the author says that the genome cannot be old because the genome is "decaying". Decay is a very subjective term, but in this case he means ...
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Is Mutation Theory still “valid” for complex organisms?

I'm afraid like most people I suffer from having learned "A History of Evolution" in school, rather than cutting to the chase and learning the actual "up to date" version of the subject. (Imagine if ...
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Name/Examples of Traits whose benefit is non-obvious and/or which evolve despite apparent mal-adaptivness?

I'm a graduate student in cognitive science doing work on people's explanations and learning, particularly having to do with natural selection. Often, students misunderstand natural selection as a "...
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If a trait does not appear to be advantageous to organism, why does the organism have it? [duplicate]

Why do organisms have some traits that do not appear to have any evolutionary advantage?
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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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Queller's 1985 version of Hamilton's rule

Queller 1985 ("Kinship, reciprocity and synergism in the evolution of social behavior") provides a generalization of Hamilton's rule that allows for non-additivity. To accomplish that, Queller writes ...
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How to compute the regression of individual fitness on individual phenotype

Consider a population structured in groups of two individuals. Individuals' interactions follow an additive prisoner's dilemma: \begin{array}{c |c |c|} & C & D \\ \hline \text{Cooperate (} C \...
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What is the probability of fixation for a mutant under fluctuating selection?

Here is an answer which explains how one can model the frequency of an allele that is under fluctuating selection (the selection that varies through time). Not, thinking about fluctuating selection, ...
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Modeling inclusive fitness

Consider a population of two altruist with coefficient of relatedness $r$. The average inclusive fitness of this population will be $w_{0} + br -c$. Like in this example, assignment of inclusive ...
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Current Trend in Evolution of Human Intelligence

Up front, I am specifically not interested in philosophical or ethical considerations re Eugenics and related concepts. In an effort to receive a concise answer I'll post a narrowly defined question ...
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Selection Pressure on Orca Whale Coloration

What is the proposed selection pressure that leads to the distinctive coloration of Orca whales? I can find nothing in the literature.
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Expected time for a neutral allele to reach a frequency of $p_1$ when starting at frequency $p_0$

Kimura and Ohta (1968) showed that the expected time for a neutral allele to reach fixation (given that it will reach fixation) is $$\bar t(p_0)=-4N\left(\frac{1-p_0}{p_0}\right)\ln(1-p_0),$$ where ...
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Explaining natural selection in moth [closed]

Industrial melanism is an example of natural selection. Can it be considered as a evolution due to anthropogenic action?
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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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What's the difference between stabilizing selection and balancing selection?

I came across these terms in Darwin's "Origin of Species" and I wasn't sure what the difference is.
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Hamilton's inclusive fitness approach

The underlying intuition of Hamilton's model of inclusive fitness is that we should study social behaviors from the point of view of actors -- rather than the recipients. To build his model, Hamilton ...
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Why did humans become bipedal?

Somewhere in evolutionary history homo started walking upright and became bipedal. You hear these hypotheses that, by walking upright, they could see better across the grassy savannas to escape ...
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Fecundity per woman in early humans

The average fecundity per woman varies a lot from country to country. I call average fecundity per woman the average number of born children per woman. In Homo sapiens, what was the average fecundity ...
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Survival curve in early humans

The survival curve/function describes the probability of a given individual to survive to age $x$. In humans, today's survival function is very much influenced by medicine. This leads me to wonder ...
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How does the population fitness change after a change in mutation rate?

The mean population fitness as given by mutation load theory depends only on the genome-wide mutation rate ($U$). My question is: How many generations is needed to reach a new mutation load ...
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Why estimate linear and full (linear, quadratic, and correlational) selection coefficients separately?

"We then fitted a linear regression including all three life-history traits to estimate the vector of linear selection gradients, β, for each sex (Lande and Arnold 1983). A quadratic regression ...
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How can natural selection occur at species level whilst not occuring at the individual level?

The chapter by Douglas Futuyma in 'Evolution' (Losos et al 2013, Princeton) states that natural selection can occur at the species level. Futuyma states that if natural selection occurs at the species ...
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Is genetic drift necessarily deleterious?

I read that genetic drift is random variation in the relative allele frequencies of a population. This question however seems to pin genetic drift down to increasing deleterious allele frequencies. ...
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Drake's Law. What is the genome-wide mutation rate and what are the estimates?

Drake's rule Drake's rule states that the genome-wide mutation rate is more or less constant across all species — from E.coli to the house sparrow. Data From what I think being Drake's original ...
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What is the progressive evolutionary advantage that leads to flying?

As far as I understand, all life started as non-flying and flying came about by natural selection. What is the evolutionary advantageous "path" to flying? Or is there something else to explain this?
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Niche differentiation in birds of prey

I'm not much of an ornithologist but I know enough to distinguish most Central European birds of prey. To me it is amazing that there are so many species that seem to occupy the same niche. Especially ...
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How prominent is the gene-centric view of evolution among professional researchers?

Richard Dawkins famously advocated a gene-centric (as opposed to organism-centric) viewpoint on natural selection, most notably in The Extended Phenotype. However, I have also heard "on the grapevine" ...
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What is the difference between eugenics and evolution by natural selection?

So with the working definition of Eugenics: "the aim to improve the human gene pool". What are key features that distinguish Eugenics from evolution by natural selection? I mean, besides that natural ...
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Gene duplication and subfunctionalization

I’ve been intrigued by gene duplication and want to learn more about it. I’ve read the following from here: several studies suggest that the proportion of duplicated genes retained in vertebrate ...
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Are there multicellular isogamous species?

Are there multicellular isogamous species? Seeking through the examples of wikipedia I would tend to think that there are no multicellular isogamous species.
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Ancestral states of sex determination system

Most (maybe all?) species that reproduce sexually have either genders (anisogamy) or mating types (isogamy). There exist today many different type of sexual determination system. There is a whole ...
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What is most ancestral: isogamy or anisogamy?

Sexual reproduction can be feasible with anisogamy (gametes of different sizes i.e. genders) or isogamy (gametes of same size i.e. mating types) or with undifferentiated gametes (i.e. true random ...
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Effects of selection on effective population size

Background The effective population size ($N_e$) is a central concept of evolutionary biology and is influenced by several parameters. For example: sex ratio bias affects $N_e$ $\left(N_e = \frac{...
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Definitions of robustness and canalization

The concepts of robustness and canalization are fashionable today in the biology literature. However, I am not sure of their definitions and I am not sure either that all authors actually use the same ...
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Is there an association between environmental and mutational robustness?

The robustness of a genotype is the ability of this genotype to resist (always produce the same phenotype) to various parameters such as mutations and environment. The ability of a genotype to resist ...
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Mutation-drift equilibrium and among loci variance in heterozygosity

At mutation-drift balance, the increased heterozygosity brought by new mutations is exactly equal to the loss of heterozygosity due to genetic drift. At equilibrium, the expected heterozygosity for a ...
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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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The evolutionary process in bird wings, especially with regard to winglets

In this answer on aviation.SE a comparison is made between the shapes of airplanes wings and the shapes of birds wings. It concludes with the following remark: After all, no bird has winglets. Not ...
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Components of the concept of Developmental Noise?

Developmental noise is a concept that correspond to the amount of possible phenotypic variance of a given genotype in a given environment. Intrinsic noise (aka Cellular noise) is a component of ...
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How does Natural Selection shape Genetic Variation?

Background Importance of the additive genetic variance As stated here, the fundamental theorem of Natural Selection (NS) by Fisher says: The rate of increase in the mean fitness of any organism ...