Changes in the heritable attributes of populations of organisms over time. Major mechanisms include drift, natural selection, mutation, and gene flow (migration).

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definition of tempo and mode in evolution

I am reading Punctuated Equilibria: The Tempo and Mode of Evolution Reconsidered, which mentions the "tempo" and "mode" of evolution. I'm not familiar with the related literature and when I google the ...
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Definition of Linkage Desiquilibrium (LD)

According to [wiki][2], linkage disequilibrium $D$ equals $$D = x_{11} - p_1\cdot q_1$$ where: $$ \begin{matrix} \text{Haplotype} & \text{Frequency}\\ A_1B_1 & ...
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How Sex Evolved ? and when?

As I know evolution comes bit by bit mutation by mutation How sex evolved which requires a major change in at least two individuals one to become male and one to become female ? When that happened ...
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Source of information on the evolution of aging/senescence

Do you know a good review (published peer-reviewed or an online course or whatever) that offers a good overview of all hypothesis explaining the various patterns linked with aging? I'd like this ...
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Effect of natural selection on phenotypic variance

Short background Theoretically speaking, natural selection causes a decrease in genetic variance and because the environmental variance should remain unchanged, natural selection causes a decrease of ...
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108 views

Heterozygosity and overdominance

Consider $m$ loci with heterozygote advantage (overdominance) such that the fitness of the two homozygotes is $1-\frac{s}{2}$ and the fitness of the heterozygotes is $1+\frac{s}{2}$, where $s>0$. ...
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79 views

Why haven't land animals evolved beyond urination?

It occurred to me (while urinating) that this would seem to be selected against because water is a scarce resource. Why are we constantly losing water we don't need to through urination? What is ...
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28 views

How are new chromosomes replicated into the next generation via sexual reproduction?

If an individual has a new chromosome, which is very unlikely to happen, he will not have any luck in finding a sexual partner with this same trait. How will the offspring inherit this trait. And ...
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30 views

List of heritability estimates in humans?

Many people on this site ask questions that directly or indirectly have to do with heritability in human. Do you know a list of estimates of heritability of various traits in humans? Or could you try ...
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Regarding the relation of observed human nature with evolution and/or genetics [closed]

Can the behavior/psychology of a human be genetic or is it an acquired trait?
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Book recommendations for evolutionary models

I was recently working on getting a statistical model of a DNA sequence. To do this I found that understanding evolution quantitatively seems to be quite important. I would really appreciate any book ...
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56 views

Can I force evolution in a group of cells by removing all the smaller cells?

I actually have algae growing in water in a container. I was thinking if it was possible to filter the water so that all the small cells will be filtered out and only the bigger ones will remain to ...
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Coalescent Theory - Probability for $k$ alleles that of one coalescence event occured $t+1$ generations ago

From this textbook Under the wright-Fisher model of genetic drift and under the assumption that all alleles are neutral, the probability that $k$ alleles had $k$ distinct parent alleles the previous ...
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Evolution of Chromosome Numbers

Some species have different numbers of chromosomes, as we all know. Throughout evolution, how was a species able to survive with an extra chromosome? How was this organism able to breed successfully ...
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Which was the last significant event in human evolution? What's next?

At 10.000 BC(12 ka) we became the last of the Homo species on Earth, in evolutionary terms this is a very little time range to something happen but I'm wondering ...
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120 views

What is the beneficial function of IgE antibody?

Dont tell me the "function" of IgE is to cause allergy ! In whatever texts I have seen it is written that IgE is important to cause allergies but what is the beneficial function of IgE ? Why was it ...
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What are the costs associated with carrying lots of genetic material

What are the costs (if any) associated with carrying lots of genetic material? energy for copying? raw material for copying? space in the cell? Maintenance cost (matter and energy)? time to copy is ...
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393 views

Evolution: How could all useful traits evolve simultaneously?

I have a basic question about evolution, for which I never found an answer. I understand how evolution works if we focus on one specific organ or trait. With each generation, some organism is more ...
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56 views

Book recommendation on population/evolutionary genetics?

I have recently been involved in collaborations that require me to model the population genetics of eukaryotic populations. I fear I may either be "re-inventing the wheel" or making conceptual ...
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2answers
79 views

Heterozygosity under genetic drift

The wright-Fisher model of genetic drift is: $$p_{ij} = \binom{2N}{j}\left(\frac{i}{2N}\right)^j \left(1- \frac{i}{2N}\right)^{2N-j} $$ ,where $\binom{2N}{j}$ is a binomial coefficient. From this ...
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How does GC-content evolve?

Background GC-content refers to the frequency of base pairs that are either C or G in the genome, or in other words the number of GC base pairs divided by the addition of the number of GC base pairs ...
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Why do different humans look different?

Although farmers appear to be able to tell their cows apart, cows look very much alike to me. And this similarity in appearance seems to be a general trail across the animal kingdom: one individual of ...
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Propagation of tool use in primates?

There are several famous cases of great apes demonstrating a surprising degree of wherewithal in communication and tool use - even monkeys can learn some tool use from each other observationally, even ...
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24 views

List of the biggest companies that work in selective breeding

Looking at this question, I've been wondering, What are the biggest private companies which work in both animal and non-animal selective breeding? Let me know if Biology.SE is not appropriate for ...
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30 views

Why do the neuron pathways decussate?

I learn about the brain right now, and there are crossing of neuron pathways everywhere; in the thalamus, the medulla oblongata, the pyramidal tract... And I don't understand why? What is the reason ...
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Book recommendation on selective breeding?

I am looking for a good book that gives a nice overview of the science and technics of selective breeding. I am particularly interested in the use of population genetics to support decision in this ...
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Triune brain model

I have heard about the triune brain model in biology class, but my teacher does not know much about it. What I'm curious about, is this model accepted by most of the neuroscientists, or is it just a ...
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40 views

Life on other planets [duplicate]

first of all I'm not sure if I should post this here or in the astronomy stack. I think biologist are more likely to answer my question. To make it short: Why when looking for any sort of life on ...
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70 views

Effect on fitness of mutations

What is the distribution/probability density function (PDF) of impacts on fitness of new mutations? I very welcome any partial answer that does not give the whole PDF but just some information ...
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Dominance/recessivity of new mutations

What is the distribution/probability density function (PDF) of recessivity/dominance of new mutations? I very welcome any partial answer that does not give the whole PDF but just some information ...
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48 views

Additive genetic variance with $n$ loci

The genetic variance of a quantitative trait (the quantitative trait in question is fitness) can be express as the sum of two components, the dominance and additive variance: $$\sigma_D^2 + ...
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76 views

Additive genetic variance with $n$ alleles

The genetic variance of a quantitative trait (the quantitative trait in question is fitness) can be express as the sum of two components, the dominance and additive variance: $$\sigma_D^2 + ...
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54 views

building intelligent structure with random evolution requires series of non useful steps

In order to build an intelligent design such as a bridge or a mechanical watch, you need a series of non useful steps. As far as I understand, in random evolution theory, the "intelligence" involved ...
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31 views

How can a recessive allele propagate until they manifest?

Suppose a specific gene has two possible alleles. In a given population all members have only the dominant one. By a mutation on member receives the first recessive allele of that population. Is it ...
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35 views

Can animals distinguish other animals?

Are animals able to tell the difference between other animals. I dont mean like a cat seeing a dog and thinking "Oh no its a dog". I mean how does prey distinguish predator or threat? Say for instance ...
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How does the creative process of Biological Evolution work?

In order for nature to go from microbes to man, there needs to be new information. Where does this new information come from? It is understood that Evolution basically involves three elements. ...
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42 views

Why do we find nature 'beautiful', from an evolutionary perspective?

Most people I know find nature beautiful and holidays generally involve a place that has 'natural beauty'.
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43 views

Why does ear wax taste sour?

Why does ear wax taste sour? I am interested in both the physiochemical mechanisms and the evolutionary reasons behind the sour taste of earwax.
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48 views

Evolution of bee hives

How do the instinct to create a hive appeared in bees? Is there some evidence of "intermediate" hives? With this questions i mean all the factors necessary to build a hive, including the social ...
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49 views

DNA adaptation in human life

Does our DNA adapt by human lifetime? Or do we have the same genetic information from birth to death? I mean: What is usually called "evolution" means "natural selection" like this: ...
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Are there specific features of birds that cats/small predators are attracted to?

I've recently heard a podcast, in which a professor describes one of the theories as to why we like abstract art. In his talk, he mentions an experiment with seagull chicks, in which the seagull ...
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22 views

Could mating/recombination be responsible for evolution of entirely novel features?

The diploid chromosomal architecture is rather interesting. For example, because of diploidy we Humans have to mate. Of course in that sense, because diploid organisms often have mate, this has led to ...
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141 views

How did the first sexual animal come to exist? [closed]

I am more or less familiar with the evolution theory based on mutations. Now, starting with a nonsexual being, how did the first organism that reproduces sexually come to exist.
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How do beneficial features evolve in species without progressing through detrimental stages?

I'm thinking in particular of wings on birds that would - I'm guessing - have to progress through stages during which they confer no particular advantage. Or is it that all evolved features must have ...
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How do I calculate the change in allele frequency in a haploid population under selection?

From this book For simplicity, let us consider a haploid organism and assume that the frequencies of alleles $A_1$ and $A_2$ are given by $x$ and $y=1-x$, respectively. We also assume that the ...
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How did the roar evolve from snort?

When Lions roar, or Dogs show aggression, they do that snort-roar thing. They're producing sound while inhaling. How did that come to be when all (?) other forms of sound involve exhaling? Humans do ...
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Effective population size and overlapping generations

From this book; If generations overlap, then the effective population size $N_e$ does not equal the population size $N$. I know mathematical formulations in order to find the effective population ...
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Effective population size when the population sizes varies from season to season

Let's think of a species which has four generations per year and which population size changes from season to season so that the population size is 100 in summer, 200 in spring, 50 in autumn and 20 in ...
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Linkage disequilibrium with $n_l$ loci $n_a$ alleles

Linkage disequilibrium $\left(D\right)$ for two bi-allelic loci is defined as: $$D=X_{11}X_{22} - X_{12}X_{21}$$ , where $X_{11}$, $X_{12}$, $X_{21}$, X$_{22}$ are the frequencies of the haplotypes ...
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Selection on linked loci in a diploid population

Let’s consider two linked loci $A$ and $B$ that are both bi-allelic. In consequence, we have four different possible haplotypes $A_1B_1$, $A_1B_2$, $A_2B_1$, $A_2B_2$, which frequencies are $X_1$, ...