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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Comparative Genomics

Are orthologs and paralogs examples of conserved genes? Orthologs are the genes or DNA that is present in 2 different species, having once been present in a common ancestor. It comes about by a ...
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1answer
21 views

A non human adaptive behaviour with a spandrel

Is there any adaptive behaviour in non humans which, when it is functioning as it was selected to do, creates a spandrel behaviour? In evolutionary biology, a spandrel is a phenotypic ...
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19 views

Why do plants produce so many hybrids as a kingdom?

Why do plants produce so many hybrids? I have read that they are the largest kingdom of organisms to do so. Does this have something to do with polyploidy events?
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3answers
108 views

Are there single-celled organisms that have evolved from multi-cellular ones?

I'm reading this paper about transmissible cancer cells in clams (Metzger et al. 2015) and I was wondering if there are any single-cellular organisms that are around today that are suspected as having ...
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1answer
72 views

Before Evolution was proposed by Charles Darwin, what were the leading secular theories to explain how life developed? [closed]

Outside of evolution, what were the leading scientific schools of thought that Charles Darwin contented with when he published his evolution theory as way of natural selection in 1859?
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26 views

Brain Damage from Injury? [closed]

I have a little brother (he is about 5 years old) who slipped in washroom (restroom) and got hurt on his head. His head was bleeding. We took him to the hospital and he got stapled on his head (metal ...
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0answers
21 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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1answer
32 views

Richard Goldschmidt's “systemic mutations”?

[TLDR] I dont understand the fault people had/have with Richard Goldscmidt's concept of systemic mutations [/TLDR] As a preface, I am a undergrad biology student, so sorry if this is a "Stupid ...
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1answer
38 views

The selective pressure of contraceptives

Does it seem probable that the existence of contraceptives (which has reduced human reproduction to below survival-level in many populations) will be a completely new selective pressure on human ...
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19 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.
6
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1answer
90 views

Why do women live longer than men?

According to Wikipedia and many other sources, women live substancially longer than men (over 5 years in the U.S.). Men can reproduce for much longer than women. So longer living men would have the ...
3
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1answer
42 views

Differences between Gradualism and Uniformitarianism

From what I understand, gradualism is the idea that small changes affect species over time. Uniformitarianism argues that the same processes that occurred in the past are the same as those in the ...
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1answer
47 views

Do all kind of unicellular asexual reproductions let mutations happen, resulting in evolution?

I know about fission, an unicellular asexual reproduction method, where the mother cell splits into two daughter cells. Does this kind of asexual reproductions let mutations happen, leading to much ...
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Evolution theory - roses spikes - being more bulgy doesn't give you advantage

I've seen spike, huge spike. And I thought that development of such spikes could be contrary to the evolution theory. Being „little more” spiky doesn’t give you any advantage... So those ...
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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) show 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 ...
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1answer
34 views

Homology ratio comparison between different species

I found the following homology ratio: protein coding genes of the organism with an homolog in mouse / all protein coding genes in the organism I have done this for all protein coding genes between ...
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1answer
51 views

Mathematical models of lineage selection

I'm interested in the concept of lineage selection (Aboitiz, 1991) as an explanation for why traits would be selected for that enhance the rate at which evolution can occur, rather than directly ...
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1answer
43 views

What color was the most recent common ancestor of all swans?

Was the most recent common ancestor of all swans black, or white, or some other color? How do we know, and how certain can we be?
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46 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 ...
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Is it known how the first viruses formed?

The oldest known virus is known to have infected prehistoric insects 300 million years ago. A virus is basically a parasitic strand if DNA or RNA encapsulated in a protein coat. It enters cells by ...
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28 views

What factors, other than its homochirality, make our “brand” of biology unique? [closed]

If humans were to discover organisms on another planet, it is supposed that (unless both we and they were seeded by the same source) we would have nothing to fear from alien pathogens, as they would ...
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1answer
70 views

What is the relationship between radiation and evolution?

There is always a certain amount of background radiation present, for example due to ionizing radiation from the sun and other stars. Also certain materials like granite may emit relatively large ...
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2answers
52 views

How can (or did) Deinococcus radiodurans continue to evolve after developing resistance to mutation?

Deinococcus radiodurans has a remarkable ability to resist damage to its DNA due to radiation, dehydration or (to my knowledge) any other source. It keeps multiple copies of its genome and has a ...
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1answer
45 views

How did bullying arise evolutionarily?

By bullying, I mean individuals harassing others with name-calling or violence but not for the purpose of gaining resources such as with extortion or theft. The only explanation I've thought of is ...
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1answer
48 views

What is the minimum functional biological light sensor? [closed]

As a follow up to this question regarding the evolution of the eye, it was suggested that primitive eyes only needed to evolve a light sensor and could perhaps use the existing biochemical cascade ...
6
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1answer
76 views

Genotype to phenotype map and the G-matrix

Suppose I have a genotype-phenotype map defined by the matrix $\mathbf{Z}$:         The scalars $G,P$ represent the number of genotypes and traits, respectively. ...
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34 views

Why is an increase in the amount of oxygen in the atmosphere favorable for life?

I have followed the David Attenborough series on 'First life' and heard, that an increase in the amount of oxygen in the atmosphere, as it took place just before the Cambrium, is generally favorable ...
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131 views

Reasons why living fossils exist?

A living fossil is a living species (or clade) that appears to be similar to another species otherwise known only from fossils, typically with no close living relatives. A living fossil is ...
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188 views

What proves that speciation is a pairwise process? [duplicate]

I have been asked this questions by many biology students and even non-biologist without a pretty straightforward answer to give. We are quite accustomed to phylogenetic trees where a common ancestor ...
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2answers
180 views

What is the minimum eye?

What is the minimum eye which confers some evolutionary advantage? By minimum I mean anything less than this has no advantage whatsoever and therefore is not favored by natural selection. By eye, I ...
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1answer
37 views

Examples of extant animals in a submature morphologically unstable evolutionary state?

I'm fascinated by evolutionary theory and the predictive aspect of it-the notion of an animal entering a strongly divergent state of evolution whereby it is evolving into a new form yet remains ...
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1answer
45 views

How does the value of K determine number of local optima in NK model?

BACKGROUND The NK model of fitness landscape considers N states which can interact with K other states. For example N is the total number of genes in a haploid genome and K is the number of other ...
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1answer
74 views

Why do Lapidaria margaretae look like stones?

Previous Research I stumbled across a trending reddit post "Lapidaria margaretae looks like stones" (as of 3rd Februrary 2015); but I could not find discussions as to reasons behind why. Question/s ...
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1answer
49 views

Can life forms exist from simple structures not made of the four bases? [closed]

I understand that all life forms on the planet are made from adenine, gauatine, cytosine and thymine, which chemically joined together to form RNA or DNA (correct me if I'm wrong). This goes on to ...
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1answer
47 views

Fixation rate at neutral loci

It is a classical result that the expected time for a neutral mutation to occur and to get fixed is $2 N \mu \frac{1}{2N} = \mu$, where $N$ is the population size and $\mu$ is the neutral mutation ...
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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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1answer
99 views

Why have whales and dolphins not evolved to have gills?

It seems at first glance that it would be an evolutionary disadvantage for a sea creature to have to come up to the surface on a regular basis in order to breathe, so why are there animals (e.g. ...
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3answers
98 views

How is it possible for the absolute fitness to be more than 1?

The wikipedia definition of Absolute fitness is "the ratio between the number of individuals with that genotype after selection to those before selection. It is calculated for a single generation and ...
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1answer
64 views

Do men and women have parts of the brain that show different level of activities? [closed]

I think that men and women are different mentally (but nonetheless equals), however this way of thinking is very hard for me to explain philosophically, so I'd like to learn about what roots this ...
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3answers
105 views

Is there a fundamental reason that plants cannot fix their own nitrogen?

Plants must have nitrogen to grow. According to the answer to this question, there are no plants can fix their own nitrogen (without the help of bacteria). Plants get their nitrogen in the form of ...
3
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1answer
33 views

What is the purpose of narwals' tusks?

I've heard that narwals can grow their tusks up to 16 ft long. What do they need the tusk for? Hunting? Comunication?
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1answer
150 views

Pros/cons: linear vs. circular DNA [duplicate]

Why did Eukaryotes evolve to have linear DNA and not circular like Prokaryotes? What are the pros and/or cons?
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1answer
44 views

Core architecture of the body encoding [closed]

First of all, I am not a biology guy; I am in Computer Science. But, I have a strong interest in all the mysteries of nature, from universe to human body. So, I want to ask a question related to ...
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0answers
18 views

Why didn't animals evolve wheels for locomotion on land? [duplicate]

It seems that our technology heavily favors wheels for the locomotion of machines over land, but evolution came up with legs instead. The following assumptions might be wrong, I'm merely speculating, ...
4
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1answer
63 views

Visualising a subset of the tree of life

I understand that many curated trees of life already exist (eg http://tolweb.org/tree/) but is there any website that allows one to input a list of organisms, and then produce the current best guess ...
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73 views

Why is iodine used for metabolic hormones?

Iodine and related biological iodine-carrying hormones are phylogenetically very old, at least according to Wikipedia. Humans use iodine as a metabolic indicator, as do axolotls and apparently most ...
8
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1answer
141 views

Why aren't green eyes more prevalent?

Why aren't green eyes more prevalent, given that the green allele is dominant over the blue one? My understanding is that human eye colour is determined by two genes: 1) HERC2, with alleles Bx, BB ...
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0answers
29 views

Why does death exist? [duplicate]

The biological purpose of an organism is to reproduce and as soon as reproductive age is passed, aging kicks in and eventually leads to death. (This is what I learned from a gerontologist.) But then, ...
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1answer
75 views

What evolutionary advantages are provided by ovoviviparity?

I read that some sharks are ovoviviparous. What advantages and disadvantages are provided by this type of reproduction as opposed to egg laying and live birth?
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Why are the fertility rates of large predators kept low?

Predators at the top of a food chain, like lions, seem to have a relatively low fertility rate, which fits well to the ecosystem and avoids overpredation. But what is the mechanism that keeps the ...