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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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 ...
7
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80 views

How to define “Quasifixation” in continuous approximation of finite population?

Background Many models including the famous very first models derived by Sir Ronald Fisher in his early career, assume infinite population size. In an infinite population, an allele can rise in ...
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53 views

What were the first neural systems like?

I'm curious about the origin of the neural network. I'm thinking perhaps once life evolved beyond the single cell organism, it needed a simple neural network to coordinate those cells, and cell ...
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27 views

Understanding F-statistics in population genetics

I am reading a classical Weir and Cockerham 1984 paper about Fst estimation. At the beginning (first page, right column), they define 3 statistics. $F$ is the correlation of genes within individuals ...
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37 views

Evolution of Wheat

In the evolution of wheat, there are two instances of chromosomal doubling, when Emmer wheat Triticum turgidum was formed from Einkorn wheat, and when Triticum aestivum was formed from Emmer wheat. ...
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23 views

Wolbachia - cytoplasmic incompatibility

I read that cytoplasmic incompatibility in Wolbachia occurs when wolbachia-infected male insects mate with wolbachia-free female insects and produce non-viable offspring. By contrast, ...
3
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44 views

How to understand relatedness in an infinite island model?

My understanding is that the relatedness coefficient in kin selection models measures positive assortment. That is, altruism is more likely to evolve if altruists tend to interact with other ...
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31 views

Why do naked mole rats live in colonies with a queen?

What was the evolutionary advantage in having queens? Is it because the ones that had queen like tendencies in the new environment had kids that cooperated better giving higher chance of survival of ...
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79 views

Up to date, extensive documentary about dinosaurs?

I just finished reading the Wikipedia page about dinosaurs, and I very much enjoyed it. I knew that much of what I learned in the 80's as a child is (and was) incorrect, and now that I am a parent, I ...
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70 views

Largest direct ancestor of humans

Going back the genealogical lineage from present humans to the beginning of life, what was the biggest - in terms of body size or mass - animal in this sequence? More generally, what would a time vs. ...
3
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80 views

Understanding the meaning of $s$ and $t$ in a population genetics equation

Sewall Wright in this article (1937) at the end of page 313 gives the equation: $$\Delta q = (s+tq)q(1-q) \space\space\space\space\space\space\space\space\space(1)$$ This equation is an ...
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84 views

At what rate do chromosomal rearrangements occur?

How often does chromosomal rearrangements occur? i.e. what is the rate of chromosomal rearrangements? I am interested about these kind of chromosomal rearrangements that are passed on to the ...
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18 views

Evolutionary motivation behind number of neurons in DCMMP

I'm studying neuro-anatomy right now and I was surprised to learn that there are only three neurons along the Dorsal Column Medial Lemniscal Pathway (DMLP) which relays mechanical sensations from the ...
3
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51 views

Inbreeding Coefficient and Coefficient of Relationship

Wikipedia gives the following formula to calculate a "path of coefficient of relationship" between an ancestor $A$ and an offspring $O$: $$\rho_{AO} = 2^{-n} \left( \frac{1+f_A}{1+f_O} \right)^{1/2} ...
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27 views

What form of reproduction did the first land animals use?

What form of reproduction did the first animals on land use*? Were they hermaphrodites, or did they have male and female sexes? [Is there a proper term for sexual separation in a species?] Were any ...
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24 views

Why does bacillus thuringiensis produce bt toxin?

Background : B.thuringiensis produces an inactive crystalline toxin during sporulation which when ingested by an insect, gets activated and causes pore formation in gut , subsequently leading to death ...
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44 views

How does the population fitness changes 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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61 views

What are the common methods to estimate additive genetic variance?

Additive genetic variance can be estimated in a number of ways, and is a key concept in evolutionary biology and quantitative genetics. What are the typical methods (experimental designs) used to ...
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49 views

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 ...
2
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73 views

Does the Jungian notion of collective unconsciousness have any legitimacy in the light of modern neurobiology and epigenetics?

Carl Jung has long ago proposed a rather controversial notion of collective unconsciousness [1, 2, 3], a form of the unconscious (that part of the mind containing memories and impulses of which ...
2
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196 views

Mutation-Selection-Drift Equilibrium

mutation-selection-drift equilibrium is one of the most important concept of population genetics. I could easily find the calculations for mutation-secltion equilibrium and for mutation-drift ...
2
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0answers
75 views

How likely is it that through dog breeding, tail-wagging has been disassociated with happiness?

I am not a biologist, so sorry to anybody for misinformation in this post. If I understand correctly, dogs evolved the ability to show emotions through various sounds and tail-wagging in order to ...
2
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51 views

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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51 views

Odds of Fusion of Chromosome #2

There is strong evidence that chromosome 2 in humans is a fusion of two chimp chromosomes (i.e. common ancestor of chimps and humans) as explained at wikipedia here The question is what are the odds ...
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46 views

$F_{ST}$ and the genetic variance in metapopulations

From this video (21'15''), the speaker gives the following formulae in order to calculate the between and among populations genetic variance from the $F_{ST}$: $$V_{Among Pop} = 2 F_{ST}V_G$$ ...
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35 views

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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56 views

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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24 views

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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11 views

Are amantadine and rimantadine MOAs unknown to evolution?

Are any natural (human or otherwise) antiviral mechanisms similar to the antiviral mechanisms of amantadine and rimantadine, or are these mechanisms undiscovered by evolution? Are drug researchers ...
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95 views

Were we able to create vitamin B12 in past?

All herbivores produce vitamin B12 de novo. Gorillas, for example, are "vegans" so I suppose some human ancestor was also herbivore. Have we ever been B12 self-producers? If so, why have we lost that ...
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21 views

Analytical Methods for Estimating Probability of Fixation

The probability of fixation $P$ of an allele is an very important measure and there exists several solutions to estimate this probability. Each method has its own assumptions and it is often hard to ...
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16 views

What is the probability of fixation for a mutant under fluctuating selection?

Here is an answer which explain how one can model the frequency of an allele that is under fluctuating selection (selection that varies through time). Not, thinking about fluctuating selection, there ...
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43 views

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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64 views

Baby birds hair and mammal hair is a convergent evolution?

Chicks (baby of chickens) and ducklings seem to have fine hairs, at least something look like hairs to me. Most mammals have hairs, but reptiles, fish, or other animal groups do not have hairs as far ...
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110 views

First documented beneficial mutation?

I've been reading up on beneficial mutations, and am curious when we discovered and documented the first one. Can anyone point me to the first documented beneficial mutation? Per request, let me ...
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37 views

Do Parasaurolophus have hands with fingers to grab?

http://en.wikipedia.org/wiki/Parasaurolophus#mediaviewer/File:Parasaurolophus_cyrtocristatus.jpg I cannot tell if the hands have fingers strung together to form a hove, or fingers to grab. I have ...
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91 views

The skin color of bonobos

Why is that bonobos skin color on the areas not covered by hair are dark throughout life unlike the chimpanzee?
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24 views

Evolutionary reasoning behind redundancy of CST and RuST

According to my neuro-anatomy class, both the Corsticospinal Tract (CST) and the Rubrospinal Tract (RuST) control upper limb movement. What the evolutionary reasoning behind this redundancy and the ...
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44 views

Why do spiders have a leaf at the bottom of a piece of web?

I've lately seen a lot of instances where a leaf is dangling from a piece of web coming down off a tree. What purpose/s does this serve for the spider? Is it some sort of mechanism for the spider to ...
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37 views

Evolution of sexually concordant genetic variation on the X-chromosome

It was theorised in 1984 that sexually antagonistic genetic (SA) variation should more easily evolve on the X-chromosome. This is partly because female beneficial/male deleterious mutations face less ...
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81 views

Can human change its morphology or anatomy due to ecological changes?

According to Charles Darwin, as the surrounding environment changes, so changes the anatomy or morphology of a specific organism. But nowadays, humans have become very advanced in the technology and ...
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37 views

Study case of the inheritance system of Oenothera

I've been told some interesting facts about oenothera. Apparently in this species some lineages have been through some translocations and in results to these translocations and in consequence, some ...
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155 views

Effects of Genetic Drift on Linkage Disequilibrium

From what I understood of @Canadianer's answer here... Genetic drift randomly causes negative or positive linkage disequilibria, by changing allele frequencies through random sampling. Natural ...
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19 views

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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25 views

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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54 views

Cambrian explosion and evolutionary arms race

I've seen many times mentioned in textbooks and popular articles that a reason of the Cambrian explosion is an 'evolutionary arms race' between predators and prey. But this isn't really a sufficient ...
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113 views

Why aren't antheridia and archegonia touching?

Antheridia and archegonia are the two male and female gametangia, respectively, and they are found in bryophytes. To cause fertilization, usually a thin film of water must be present for the sperm ...
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16 views

What chordata evolve first limb

I try to search when and what specie develop first bone limb. I also want to know when second pair develop. And first pair was front or back one? And why it stop only at 2 pairs. Are there any fish ...
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34 views

Saline solution for animals

A popular "well-known fact" is that all creatures on Earth consist mostly of water (i.e. H2O). Indeed, a liquid called "normal saline solution" is just a solution of 0.9% sodium chloride in distilled ...
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51 views

Does embryonic development mimic (partly at least) the evolution of organisms on earth?

What do we know about the forces/mechanisms which lead to this seemingly "fast forward" evolution stages of the embryo? What are the theories dealing with this idea?