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5

First of all, here is a program which simulates the evolution of the G-matrix over multiple generations, it's a few years old (they seem to have stopped developing it) and I've only played with it briefly. This could solve how to model the evolution of the G-matrix. Fisher's fundamental theorem is a great place to start off with the theory of this: The ...


5

As part of your question, you ask if other animals can create sound without continuous airflow. Many insects (e.g. cicadas and moths) do exactly this by using tymbals. A tymbal/timbal is an external membrane organ that is controlled by muscles or wing movements, that cause the membrane to flip back and forth, creating clicks or other sounds. So in many ways ...


4

Recap of the question: Looking at a single locus trait ($A$) controlled by two alleles, $A_1$ and $A_2$, the phenotypic mean is only affected by inbreeding depression, $f$ (Wright's inbreeding coefficient), if there is some degree of dominance, $d$. Why? Answer: If we take inbreeding as a higher than expected frequency of homozygotes, such that if the ...


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Not all cat predatory behavior is innate. Researchers found that cats predatory behavior for birds vs. mice depends to a significant degree on training by the mother: if the mother taught predatory behavior with birds, the kittens grew up to be better at catching birds than at catching mice and vice versa. Supportive data shows that aside from monkeys and ...


4

Here is a list of woodwind instruments. Do you know of any (non-open) reed instrument that produces a note without anyone blowing air through them? Imagine a clarinet being played on someone's lap pouring out a melody. That would be very, very remarkable indeed. Our ability to produce sound from our throats is in theory like a reed instrument in music. ...


4

Note: This is not an area where I know the litterature well Where are many counteracting processes to consider for this question. For instance, the rate of evolution will be affected by the rate of mutation, the distribution of positive and deleterious mutations, strength of selection, whether the fitness effects are small or large, if fitness effects ...


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The current thinking amongst biophysicists is that if we all woke up tomorrow to find that someone had edited the book of life so as to exchange all of the L-'s and D-'s (and made similar mirroring changes to all of the molecules that any protein interacts with), everything would be exactly the same. Milton, et al. (Science, 1992) lent supporting empirical ...


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As you say yourself, biological molecules are usually available in both chiralic possibilities, yet nature uses only one of the two possibilities. At some point in our molecular evolution (and at a very early one) L-amino acids were stochastically "chosen" over their D-equivalents (I think that the choices would have been equiprobable). There is no reason ...


3

This is a common misunderstanding from newcomers in evolutionary biology. Not every trait is the result of an adaptation. Evolution is way more than just natural selection and is not as deterministic as you may think. There is stochasticity inherent to mutational processes and there is stochasticity in reproductive success (called genetic drift). This ...


3

I think robustness and plasticity are different concepts, although related to each other. I would define plasticity as the property of a system to adapt to external changes. As defined in the wikipedia page for phenotypic plasticity: Phenotypic plasticity is the ability of an organism to change its phenotype in response to changes in the environment. ...


3

A mutation is a change in the genetic code - this can either be in the DNA or for viruses also in the RNA which carries their genetic information. This can either happen due to external influences (chemicals, radiation) or internal (mistakes while copying the information) reasons. See the figure below which shows the principle: DNA based lifeforms usually ...


3

I am presenting a speculative approach since nobody has mentioned about any existent models yet. Assuming that selection is based on performance in certain tasks; performance is a function of traits which in-turn is a function of genotype. Performance is a non-linear function of genotype and selection imposes a cutoff/bandpass filter on the performance ...


3

The time before Darwinism, people believed life as an entity which is created rather evolved. But there were great biologists interested in the relationship between species, who deliberately thought of evolution ideas and some of them believed in ape-human similarities and placed humans and apes in same group. In 1699, Edward Tyson, an English anatomist, ...


3

Tracing it backwards this was the earliest reference I found via google scholar, it's from 1988 and uses the $r B C$ notation in the format we are used to. Hamilton's rule states that for a social action to be favored under natural selection, rb - c > 0, where c is the cost to the actor in terms of the effect on (usually a reduction in) his expected ...


2

Modern humans are continuing to evolve. Let me give you an example. Before cattle were domesticated over 99% of all adults were lactose-INtolerant (i.e., they did not produce the enzyme needed to break down lactose (lactase) and could not digest it, i.e. got diarrhoea if they drank milk). All infants produce this enzyme, but in lactose-intolerant people the ...


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I think you have misunderstood the passage. Here is a larger section (found at google books): Natural selection can also occur at the level of species, for certain characteristics enhance the rate of origin of new species or diminish the likelihood of species extinction. For instance, the number of species in lineages of herbivorous insects has generally ...


2

Cooked food is a learnt trait rather than an evolutionary one. On a certain psychological level its a society norm so you would be hard pressed to find an individual who wouldn't mind eating completely raw meat/steak. But, say if you chuck a few humans into the wilderness at an early age and not teach them how to cook meat they may not actually cook their ...


2

This post is very related to your question and is definitely worth reading. I hope your teacher didn't really say that! It is really not as easy as he's suggesting. There are a number of studies that address the question on whether Sexual Selection (SS) and Natural Selection (NS) have opposite or antagonist effects. The subject is not easy and as SS is not ...


2

Could not fit in a comment.. Welcome to Biology.SE! Here are a bunch of comments. The sentence until it evolves into a new species and / or the old ones become extinct sounds weird and there seems to be some confusion between evolution and speciation. Also it seems that you have a very static view of what is a species, as if species were predetermined ...


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There was a paper that attempted to assess this published in 2010 There’s plenty of time for evolution - Herbert S. Wilf and Warren J. Ewens There is also a layman's explanation of this here Basically when we account for the fact that genes evolve in parallel under a number of simultaneous trials, it appears that there is indeed enough time for species to ...


2

Pigmentation in most animals which is between black, brown, red, yellow and which is made up by the mixture of two pigments: Eumelanin (yellow to red) and Pheomelanin (black to brown). The ratio between these two makes a color. These are pigmental colors which are made by a special kind of cells in the skin, in mammals they are called melanocytes (and I will ...


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With very large population sizes like this the effect of genetic drift goes to zero, which is greatly simplifying. I'm also assuming selection is very strong, so that fixation times are small, and that mutation rates and population size more or less cancels out, so there are a finite number of mutations and the selection space is relatively unexplored. If ...


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Here is a link with a plain-English popular-scientific web article published online by the first author.


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It's not entirely clear what you're asking. If you're asking whether domestic animals are more friendly to humans than wild animals, the answer is generally yes. However, this does not make them "more evolved". Domestic and wild animals are ultimately derived from a shared common ancestor, so they have been evolving for an equal period of time. In ...


2

Domestication has little, if anything, to do with intelligence. From biologist Jared Diamond, the 6 criteria for domestication are as follows: Flexible diet – Creatures that are willing to consume a wide variety of food sources and can live off less cumulative food from the food pyramid (such as corn or wheat), particularly food that is not utilized ...


1

Deciduous trees are those which shed their leaves once a year at the time of winter season and later grow new leaves, plants those keep their foliage throughout the year are called evergreens. Deciduous trees usually have broad leaves e.g., ash, beech, birch, maple and oak. There is a confusion exists over the dominance of trees in rain forest, but most of ...


1

I think that the claim "different drugs properties come from different part of the world" is an illusion due to statistical mis-considerations. More accurately, there are 3 statistical issues here. Your sample size is too small to draw any conclusion. You only have 3 observations in one group and 2 in the other group. Your observations are not ...


1

While its possible humans could speciate into two distinct groups at some point in the future, it hasn't happened recently (100 kya) and it doesn't seem to be happening now. If it were happening we would see two or more distinct populations that didn't interbreed and over time accumulated increasing differences. These skin colors track most of the evolution ...


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I think there is some misunderstanding there, natural selection does act on an individual and can be determined by its genes (assuming there is genetic variance underlying the variance in trait). Those with more favourable genes will have more favourable phenotypes and thus be more likely to survive/reproduce. However, (genetic) evolution does not occur ...


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I assume that the figure comes from a section on genetic drift (since this seems likely), and it shows how the allele frequency will change over time under drift in a diploid population. So in short, each line represents the distribution of allele frequencies in different hypothetical populations, that all started with the allele frequencey p=0.5. As for ...



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