Evolution refers to the observed changes in successive generations of biological organisms due to heritable components (genes and DNA). Charles Darwin proposed a major mechanism of evolution: natural selection.
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Has medical progress stopped human evolution?
We can cure many diseases nowadays, and thus the natural selection is very limited.
Plus, mankind spent the whole beginning of its existence in almost the same hostile environment, and that's where he ...
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Is local equilibrium a reasonable assumption for evolutionary processes?
Whenever I look at discussions of fitness landscapes (in particular, Kauffman's NK model) the questions tend to resemble:
The population is at a local equilibrium, but another equilibrium of ...
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When does weak selection produce qualitatively different results from strong selection?
In evolutionary game theory, it is typical to model organisms as having a base fitness that is modified slightly by the game interaction. The ratio of the game effect versus the base fitness ...
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Are there natural selection experiments that quantitatively agree with theoretical modeling?
Has anyone ever conducted an evolution experiment and quantitatively compared it to theory? For example, has anyone ever put bacteria in a million petri dishes filled with antibiotics and calculated ...
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Why is a slow worm not considered a snake?
Slow worms are considered lizards as opposed to snakes, both are reptiles. Now I get that there are traits that distinguish them (eye lids, ears ...). But snake species themselves vary already quite a ...
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Why do eukaryotic organisms have introns in their DNA?
We touched on introns and exons in my bio class, but unfortunately we didn't really talk about why Eukaryotes have introns. It would seem they would have to have some purpose since prokaryotes do not ...
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What are some examples of scaling laws in biology?
I've seen that metabolic rate scales logarithmically as function of mass for many animals over an extremely large span of parameters. What other scaling laws exist at the individual level?
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If Evolution Is In Progress, Why Fight Extinction?
Natural selection is a central dogma of evolution. However, most biologists seem determined to prevent the extinction of the species that have been selected against. Why is this? Preservation of ...
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Why are there exactly four nucleobases in DNA?
Does someone know why DNA is composed of four nucleobases? In particular, is there an explanation for the number? Why four and not two, or eight?
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What is the evolutionary reason behind the fragility of teeth?
Almost all organs in the human body have a rather large threshold within which the organ or tissue is capable of repairing itself using materials supplied by the body, whether it's made from organic ...
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Why are there no wheeled animals?
In physics, "almost everything is already discovered, and all that remains is to fill a few unimportant holes." (See Jolly.) Therefore, on Physics SE, people are veering off into different directions: ...
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How many times did endosymbiosis occur?
According to the endosymbiont theory, mitochondria and chloroplasts originated as bacteria which were engulfed by larger cells. How many times is it estimated that this occurred in the past? Are there ...
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Does pheomelanin have a useful biological function?
Melanin is a natural pigment that is categorized into two main forms, eumelanin and pheomelanin. It's well documented in the science literature that increased eumelanin levels reduces the risk of ...
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What is the difference between orthologs, paralogs and homologs?
These three terms are often misused in the literature. Many researchers seem to use them as synonymous. So, what is the definition of each of these terms and how do they differ from one another?
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Why do sloths come down from the trees to defecate?
I'm under the impression that most sloths exhibit this behavior, but why? They are slow moving and so have no way of escaping from predators when on the ground. Not to mention the energy they expire ...
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What was behind the evolution of human brain? [closed]
Why did the human brain evolve!?
certainly it was not selective evolution, it seems something inside DNA forced human to evolve through brain
Evolution (or development process of human) is more ...
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77 views
The oldest common ancesstor of all human beings
Do all human beings have a single oldest ancestor (a man and a woman), or were there were many ancestors at the same time at different places on earth?
This article sheds some light. Is there another ...
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648 views
Can two humans with 44 chromosomes produce viable offspring?
It is known that there are very few individuals having 44 chromosomes, not the usual 46 chromosomes.
One example is a male in China: the first article, the second article.
The other is a female in ...
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Why does sexual selection evolve beautiful features?
First question here. I have a very raw understanding of sexual selection:
Say a group of females of a certain species "likes" some feature of a certain groups of males; by "like" I mean some ...
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Is there are evolutionary explanation for why humans and primates are ticklish? How might it have evolved?
Tickling is a rather interesting phenomenon: When humans or apes are touched in certain areas like the armpits or sides, we respond with laughter AND frantic attempts to stop the assault. Obviously ...
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Is there an advantage to linear chromosomes?
The DNA copying enzymes have a hard time working to the end of a chromosome. For circular chromosomes this is not a problem, since there is not a sharp 'end'. However, for a linear chromosome, without ...
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Macroevolution vs. microevolution
Where is the line usually drawn between macroevolution and microevolution?
I thought that, although similar processes govern both, the line was at the species level, with macroevolution being changes ...
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Lineage selection in plasmid evolution
I've been reading through Paulsson (2002) and I am not sure what he means by "lineage selection" in the second to last section. The paper deals with plasmid replication, and mostly concentrates on the ...
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Mathematical Modelling of Natural Selection
I'm a math undergrad looking for some papers on modelling the process of natural selection. The only paper I've been able to find is by the pre-eminent mathematician Herbert Wilf from 2010,
There's ...
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Structure of fitness landscapes in the NK model
The NK model of rugged fitness landscapes consists of $N$ sites where fitness contribution of each site depends on its state $\{0,1\}$ and is epistatically affected by $K$ other sites. When defining ...
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Are there any examples of sudden leaps in evolution?
As far as I understand, various abilities like flying, sight, hearing etc. were caused by slow evolution, where those with a greater ability to to these things had better chance of survival. (If this ...
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Reproductive isolation causing evolution
My course book says about reproductive isolation that it does not allow the interbreeding among the individuals of different species. It also says that it is a cause of evolution.
How is this cause ...
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Why does the PR form of phytochrome exist?
I know how it gets converted because PR is more stable and when there is neither red or far red light PFR naturally converts to PR. But what is the point of it? If PFR is the biologically active one ...
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Is it possible to make bacteria vulnerable to antibiotics it's resistant to?
Since bacteria becomes resistant to antibiotics after an unfinished course, is it possible to do anything to be able to get treatment with the same antibiotic again, and reverse the resistance in the ...
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What's the Evolutionary Purpose of Religion? [closed]
I would imagine the answer to this question would be that religion tends to cause greater compliance of individuals within society, so it is pro-society. Plus these religions tend to incorporate some ...
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How can homosexuality evolve despite natural selection?
I would imagine that the answer to this question would be population control, especially since even if one sibling is homosexual this does not necessarily mean that the other siblings will be too.
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How did this spider evolve to mimic exactly a human face and arms?
So I came across something terribly amazing today, that is, a video showing this species of peacock-spider, that literally, transforms into a human face waving his arms about.
What could have ...
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Cyanobacterial photosynthetic oxygen yield
I am somehow not convinced that biotic factors are solely responsible for creating 21% of atmosphere (around 40 million moles of oxygen).
There may be additional issues here. Since cyanobacteria ...
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Alternatives to fittest-win and Moran processes as simple mathematical models of selection
When modeling selective sweeps as a micro-building block in models of macroevolution (not to be confused with misuses of this in creationist arguments), I use the fittest-win model of selection as a ...
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How might gene clusters like the lac operon evolve?
The obvious answer for a gene cluster is gene duplication and mutation of one or both genes. But the genes in the lac operon seem not be so functionally/structurally similar (as compared to the Hox ...
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Zero selection in evolution
The evolution is creative because of random-generated solutions and useful because only best solutions are selected. The natural selection not only brings species to perfection but also keeps them ...
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What factors are known to affect evolution?
My understanding is that the possible mechanisms of evolution are:
Environmental changes
Cultural/mating preferences
Population Immigration
Genetic Mutation
Am I missing anything? I've heard that ...
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Why do some people find vegetables so repellent when evolutionarily they should find them an attractive and thus tasty food?
Why do certain people (especially kids) find vegetables so "repellent" when evolutionarily they should find them an attractive and thus tasty food?
I ask this question because if Darwin's theory of ...
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What's the Evolutionary Purpose of Hair in Humans (namely the hair that grows on their skin, NOT internal hairs)? [closed]
My guess would be the following four:
Protection from the cold (especially head hair)
UV light protection (especially head hair but hair elsewhere would also protect from UV light in times when ...
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Can this theory on the evolution of human appearance be flawed?
This is what a friend of mine said:
When there's human offspring, it will look a rough 'medium' between
the two parents, with it sharing features from the two. well if the
offspring of one set ...
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Agony, Hydrophobia and viruses in the light of evolutionary principles
I'm undergraduate physics student, but I've always been interested in biology. So I have a couple of questions about an application of the evolutionary principles to practice.
Agony as the last ...
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Indestructible Super Shrimp
How are shrimp and other animals able to not be crushed by the 1000x greater pressure at the bottom on the Mariana trench?
Wiki says the trench is home to "large living creatures such as a sole or ...
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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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Does becoming martyr have an evolutionary advantage?
This is related to
How does "be altruist to those who are similar to you" evolve?
Altruism that is
Not reciprocal
Not familiar
has little explanation. One possible explanation is that ...
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Why is selfishness the 'obvious' strategy?
Thinking of behaviours an organism can adapt, at the very base an action can always be either selfish or altruistic (cooperative).
Usually, selfish behaviour is assumed to be the preferred choice and ...
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Why is 'Grudger' an evolutionary stable strategy?
I am currently reading 'The Selfish Gene' by Richard Dawkins, which I am sure many here have read. The topic are evolutionary stable strategies (ESS) regarding cooperation.
I apologise for the long ...
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How exactly are game theoretical evolutionary models described during implementation for computer simulations?
When a biologist or a layman tries to reason the evolutionary explanation for something, they would simply use English with some math thrown in (for a random example, pick any explanation out of "The ...
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What is the difference between a circular and a cat's-eye pupil?
I've been to local zoo the other day and one lizard caught my attention: its pupils are circular, which, I thought, is not usual for reptiles. Turns out it is, but now I can't find any explanation on ...
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Is there any evolutionary/physiological advantage to multi-lateral symmetry?
Just wondering ; I get the impression a large number of multicellular organisms are multi-lateral in their physical structure. Why would evolution/mutation have retained multi-lateral symmetry in an ...
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Plants without bacteria? is it theoretically possible?
I know from school, that all live on the Earth need bacteria as low-level "machines" that break down/extract/convert/produce chemical elements and combinations, other high-level organisms needed. But ...
