Changes in the heritable attributes of populations of organisms over time. The mechanisms of evolution are mutation, migration, drift, and selection.

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Darwin's first sketch of a phylogenetic tree

Coming from Darwin's notebook this first sketch of a phylogenetic tree became one of the most emblematic image from Darwin's work. I have a hard time to read what is written on it. What is written ...
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14 views

Why don't male cheetahs rear their offspring?

It seems like a huge evolutionary advantage to do so. It could prevent their cheetah cubs from getting eaten when their mother is hunting. Maybe that's not a big evolutionary disadvantage because when ...
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58 views

Have people in Africa already started evolving resistance to AIDS?

Are people in Africa who have sex with somebody with AIDS noticeably less likely to die from it than they once were because some of the people without genes that give them resistance already died off? ...
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1answer
31 views

What are Some Classical Examples of Local Adaptation?

Question Can you please give a list of classical (textbook) examples of local adaptations? How to answer Examples don't necessarily need to include what evidence supports this specific example of ...
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3answers
4k views

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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1answer
34 views

A doubt on Introgression

Wikipedia says that Introgression, also known as introgressive hybridization, in genetics is the movement of a gene (gene flow) from one species into the gene pool of another by the repeated ...
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21 views

Seasonal and Ecological colours [on hold]

Is the following correct? Difference between ecological colour and seasonal colour: Ecological colour It is the colour that remain throught the year and does not change with season. e.g.- Cryptic ...
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1answer
14 views

Statistical genetics: Allele frequencies that follow a Dirichlet distribution

From Foll and Gagiotti (2008) (software BayeScan). They consider a model where several subpopulation are derived from a unique ancestral population. We consider a set of $I$ loci and let $K_i$ be ...
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1answer
55 views

How to read cladograms/phylograms?

I understand the difference between cladograms and phylograms; the latter can show the evolutionary linkage over time. However, I am having trouble finding out which two organisms are most closely ...
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14 views

Speciation : More rapid in sexual or asexual population [on hold]

A similar species of plants exist at two altitudes. At higher altitudes where pollination is low, the plants reproduce asexually. Whereas at lower altitudes where there are pollinators cross ...
3
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1answer
61 views

Do animals have different taste preferences within the same species?

Humans (especially children...) seem to dislike certain foods or drinks, that other humans seem to like. Common examples are coffee, french cheeses, milk, fish and cabbage. Are there examples of ...
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1answer
52 views

Evolution to store limited Fat

Why are our bodies not evolved to store only limited amounts of fat, which won't kill us with all diseases associated with obesity? Wouldn't obese people die faster and clean the gene pool for people ...
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54 views

Why we evolve to loose wisdom teeth(small jaw) and seemingly trivial traits? [closed]

I have recently come across couple articles that suggest humans are still evolving to have smaller jaws and loosing trivial traits such as being able to move ones ear etc. My question is, how this ...
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2answers
3k views

How can birds disperse seeds when they are able to digest them?

I've just read in a book that birds' guts can digest almost all the consumed seeds with the exception of mistletoe and loranthus (which stays stuck on the branches). On the other hand, I know that the ...
2
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1answer
47 views

What contribute to the variation of protein sequence across different species and how do they influence?

What contribute to the variation of protein sequence across different species (e.g. phenotype, environment, evolutionary pressure) and how do those factors contribute to the variation? I have tried ...
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2answers
5k views

Why is it beneficial for trees to grow that tall?

Why is it beneficial for trees to grow that tall? This sounds like a kid's question Mom, Dad... why are trees so tall? Costs and Benefits There are some obvious ...
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1answer
49 views

Is there selection against long proteins and long genes?

Background thought Titin and TTN Titin is the largest protein in the human genome with 33423 amino acids. Titin is coded by the gene TTN that must be at least $3 \cdot 33423 \approx 100kb$ long. ...
8
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1answer
160 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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2answers
35 views

Simple computational biology project for AP Biology class. Ideas? [closed]

Our teacher assigned us a project to do with an extremely open-ended prompt and it should be completed within a month. I was planning on doing something related to computation and evolution in terms ...
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0answers
28 views

What were the camels' bumps good for back in the polar areas?

I've heard that camels lived in the North America formerly and just in the last few thousands years they've migrated to the hot deserts. Thus they allegedly utilized the adaptations against the cold ...
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0answers
24 views

What model of epistasis best fit the reality?

In theoretical population genetics, it is very common to have to assume a model of epistatic interaction. The two most common models are the additive model and the multiplicative model. Additive ...
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1answer
22 views

What negative effects does cannabalism have in other species (like prion diseases) and how are they mitigated?

It is well known that human cannibals are likely to suffer from a variety of ailments, particularly prion diseases. However a great many other species, from insect to ape practice cannibalism at much ...
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0answers
53 views

Disposable Soma Theory and the case of the contraposition

According to August Weismann (1889), Kirkwood and Holliday (1979): Because of the evolution of an organism that is segregated into soma and germ cells, soma becomes disposable, and in the face of ...
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1answer
48 views

Evolution & Celluar Chemistry [on hold]

I'm new to this site but had a question on evolution, apologies if some of these questions seem basic but they are from a book i am reading challenging the role of chance in evolution. Taking the ...
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0answers
14 views

Ewens-Watterson Test of Neutrality

The Ewens-Watterson test is one of the first test of neutrality (of no selection). Later came tests such as Tajima's D or Fu, Li's G and many other. Question Can you please make a description of how ...
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1answer
39 views

How does epigenetics know to mutate which gene in order to survive? [closed]

It seems that during reproduction particular genes are targeted for modification (mutation, deletion, insertion, etc.) given environmental inputs of either or both of the parents. If a creature was ...
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2answers
1k views

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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1answer
19 views

How to incorporate intraspecific variation in discrete characters in comparative analyzes?

I'd like to run a multivariate analysis (Pavoine et al. 2011) that aims to disentagle the effect of environmental gradients on traits, considering its autocorrelation with phylogeny and space. It uses ...
52
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2answers
8k views

What is the evolutionary advantage of red-green color blindness?

Red-green colorblindness seems to make it harder for a hunter-gatherer to see whether a fruit is ripe and thus worth picking. Is there a reason why selection hasn't completely removed red-green ...
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1answer
72 views

Why do fruits have to ripen?

It seems like most fruits that we consume undergo some sort of ripening process either before or after they are picked from the vine, tree, etc. I understand that sugars are released during the ...
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1answer
448 views

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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5answers
11k views

Why don't mammals have more than 4 limbs?

Arthropods have 6 or more limbs and arthropods with 6 limbs appear to move faster than arthropods with 8 limbs so I wonder whether this might have something to do with fast and efficient locomotion. ...
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1answer
35 views

Relationship between genetic diversity within and between species

Here is a quote from Wagner (2008) A second line of evidence [against neutralism] comes from the relationship between the mean number of polymorphic differences between alleles within a species, ...
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4answers
2k 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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11 views

Are there any pre-existing evolutionary explanations for the viscosity and abundance of canine mucus?

If there is, it's not something you find on search engines. To be honest, I first posed this question in a "Bad Ad-hoc Hypothesis" convention kind of context, but now I'm curious if there's any real ...
7
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1answer
553 views

What are the atmospheric requirements for large dinosaurs?

What are the atmospheric requirements for large dinosaurs? and are the atmospheric constituents for supporting large dinosaurs any different from the atmosphere today?
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185 views
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310 views

Are there natural selection experiments that quantitatively agree with theoretical modeling? [closed]

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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8answers
6k views

Why does evolution not make our life longer?

Why does evolution not make life longer for humans or any other species? Wouldn't evolution favour a long life?
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12 views

Is salivation decrease during sleep beneficial?

Papers [1, 2, 3] tell that a salivation decrease is not only unpleasant, but harmful for dental health. What cause that decrease? What is the reason for it and do animals have it? I guess it's a ...
4
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44 views

Did the Great Oxygenation Event also cause a mass extinction?

Its usually assumed that the Great Oxidation Event around 2.3 bya caused a great extinction of anaerobic life on earth. But as I was reading Nick Lane's book, ...
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4answers
934 views

Why would lethal genes evolve?

I've been reading through 'The Selfish Gene' by Dawkins. At a few places in the book he states that incest is damaging because it would give a very high chance of lethal recessive genes becoming ...
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37 views

Biological species concept [duplicate]

I could not understand a portion of an article I was reading. It was about biological species concept and it said ' There is difficulty in the application of biological species concept in those ...
2
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1answer
140 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 ...
2
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0answers
78 views

How does the introduction of clones would affect population genetics? [closed]

Since the ability to clone animals gives another way to preserve species, this could help for the breeding process. It has been noted that with the ability to clone animals, endangered species can ...
4
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1answer
141 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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33 views

Why did earlier humans not survive, yet apes are still among us? [duplicate]

Why did the earlier species of humans, such as the Ardipithecus and the Homo erectus, not survive, but the ape and chimp species, with whom we share 98% of our DNA, are still surviving and among us. ...
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2answers
39 views

What did cyanobacteria gain from photosynthesis?

As far as I understand, cyanobacteria began performing photosynthesis long before plant cells as we know them arrived on the scene. But cyanobacteria do not seem to use polysaccharides in the same way ...
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5answers
2k views

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.
3
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1answer
285 views

Examples of Vestigial Genes

I consider the existence of a broken GULO gene in humans to be the clearest evidence for human evolution - just what else is it doing there otherwise? Are there any other examples of vestigial genes ...