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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Why isn't the biological niche occupied by whales instead occupied by fishes?

As by the title. Why aren't there many more, and larger, whale shark like creatures instead of the great mammalian swimmers? I'd assume fish have a benefit in doing the whole "being under water" thing ...
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15 views

Rates of evolution of mitochondrial genes

I am interested in knowing the rates of evolution of different mitochondrial genes (in base pairs per million years) across different taxa. Has there been any publications along these lines ?
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1answer
120 views

Why do we breath oxygen? [closed]

I like this contradiction. But seems like my Biology teacher doesn't. If oxygen oxidates us, why do we breath it? Why can't we evolve into a new kind of human being that breaths other component of ...
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2answers
212 views

Why do squirrels have twitchy bushy tails?

Whenever I see a squirrel in the woods, it is always the big bushy tail flipping around that gets my attention first. A pray animal with a big bushy flag calling attention to it's self seems to be ...
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77 views

What causes goose bumps?

What is the actual process and reflexes that cause the goose bumps? Why is it an evolutionary advantage to have goose bumps in the first place?
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86 views

Question on Evolution [closed]

Scientists say there are 15 million insect species, 2 million marine species, more millions of bird and animal species. Yet, only one- humans - developed language. If evolution is true - that species ...
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1answer
110 views

Are there examples of animals that adapt to their environment very quickly? The phenomenon is called Phenoptic Plasticity [closed]

Evolution and speciation may take millions of years. This made me wonder if there is an animal that adapts itself relatively rapidly to its environment? I don't mean a simple adaptation like a change ...
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563 views

Why do adult insects have 6 legs?

Apparently, there is an advantage to having 6 legs in the insect world. What is that advantage, if anything? Why would such an advantage exist for insects, but not for other, larger land animals? ...
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172 views

Did we evolve from monkeys?

Since I was young, I always understood that evolution taught that we descended from monkeys (or apes, not too sure a distinction was ever made). However, someone recently told me that this isn't ...
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188 views

How quantitative is the theory of evolution right now? [closed]

We developed complex structures like eyes and brain, whose mechanisms rely on specific species of molecules and relevant chemical reactions. But we did not develop an enhanced night vision, the ...
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1answer
617 views

Evolution home experiment?

If I were to take bakers yeast and put it in medium of minimal sugar(whatever quantity that would be) and rice(for a source of starch), could the yeast have a "evolutionary leap" and adapt to use the ...
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70 views

Why did life on Earth develop with two sexes? [duplicate]

If evolution gives us the best adapted organisms for survival of the fittest, why does so many of Earth's organisms require two sexes for reproduction? Shouldn't this have been bred out of our ...
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140 views

How did the first life form on Earth reproduce without DNA?

So, the best explanation I can think of for the first life form, life happening from nothing (wow), is that over billions of years, with trillions of water molecules and dust particles and chemicals ...
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43 views

Biological Evolution outside of Earth [closed]

What drives evolution forward? I heard that climate change drives species to evolve and adapt. Is there any other mechanism that is encoded in our DNA by which species can over abrupt changes, evolve ...
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1answer
44 views

Who was the first to coin the terms of soft and hard selection?

Soft and hard selection are sometimes used with different definitions. I have been told that at first place hard and soft selection has been defined in the following way: soft selection: Each deme ...
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1answer
92 views

Is the fixation rate always equal to the mutation rate for neutral alleles?

Background A classical result of population genetic is that the rate of fixation of netreual alleles is the mutation rate $\mu$. The reason is that each generation $PN_e\mu$ mutations enter the ...
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235 views

Why are there so many different humans yet chimpanzees are just chimpanzees?

There are two species belonging to the Pan genus (Pan troglodytes and Pan paniscus). That's just two. I mean, humans have changed radically since we split from chimpanzees, we have Australopithecus ...
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125 views

The replicator equation vs the Lotka-Volterra equation

Background The replicator equation with $n$ strategies is given by the differential equation: \begin{equation} \dot x_{i} = x_{i} \left( \sum_{j=1}^{n} a_{ij}x_{j} - \phi \right) \qquad i = 1, ...
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1answer
182 views

What is a selective constraint?

I encountered the term selective constraint in Huber et al. 2015, page 4 (last paragraph) in: If invariable sites are included in the analysis, then both the methods of Kim and Stephan ...
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369 views

Why are many fruits sour?

Many fruits (like apples, berries, citrus fruits etc.) contain high levels of organic acids, especially malic acid and citric acid. Are there any evolutionary functions of those acids in ripe fruits? ...
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42 views

What are constrained genetic elements?

I am somewhat of a newbie in evolutionary biology currently taking my first steps in bioinformatics. I was reading a paper when I came across the term "constrained genetic elements", referring to ...
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1answer
80 views

What factors cause males to be more common than females in humans, from an evolutionary perspective? [duplicate]

Fisher's principle states that there should be a 1:1 ratio between males and females born on average for a population. However, if you look at birth statistics your find that boys are slightly more ...
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40 views

Evolution of blood types [duplicate]

What are the popular theories regarding how our blood divided into 4 groups. Particularly I'm interested in whether this was originally linked to disease. Thanks for your answers, useful articles and ...
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1answer
74 views

Do all mammals have a Ventricular system?

I am familiar with the human Ventricular system that circulates Cerebrospinal fluid. This is needed among other reasons, to suspend the heavy human brain, and for injury protection. Do all mammals ...
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1answer
75 views

term for species that produces males only to mate with mother or sisters

In reading about unique reproductive strategies I've run into two closely related and comparatively unique mechanics. Both involved a female who was born 'pregnant' with at least a male, but the male ...
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44 views

Variance in reproductive success and effective population size

Background The effective population size $Ne$ is the size of the Wright-Fisher population that experience the same amount of drift than the population under consideration. The higher the variance in ...
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1answer
64 views

What is the evolutionary tradeoff against primates producing multiple offsprings (litter)?

If we evolved to have multiples all the time we would more likely have extended families living together in 1 house. This would be better than the spouses by themselves for multiple reasons including ...
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Why does a coconut have exactly three holes

A theory says: As coconut is a sibling of palm, somehow long time ago, three palms were in a same husk. Based on evolution theory, it's how the coconut was born in the world with three holes. ...
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Which primates can swim underwater?

I saw a documentary awhile back and they were profiling a certain species of monkey which regularly swims underwater. I can't recall which species it was but they said it was rare for primates to do ...
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35 views

What makes tones sufficiently useful that it would lead to the evolution of tonal processing?

I will define a "tone" as  a steady periodic sound. As an example, I consider a sinusoidal wave to be a tone. By "tonal processing", I mean ratio relationships between the notes. For instance, if I ...
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36 views

Seeing through the rain

This question leads me to wonder about seeing in and through rain. From visual point of view, rain is light-bending droplets moving downwards, unformly in steady rain, less uniformly if there's ...
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129 views

Evolution of a Population

Scientists observe a newly established population of sexually reproducing plants growing on the shore of a small island. An observable trait of the plant has two possible phenotypes. It is determined ...
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1answer
330 views

Hardy-Weinberg Equilibrium Question

I have four questions concerning H-W Equilibrium: (i) In a population of mice, the presence of black spots is the result of a homozygous recessive condition. If the frequency of the allele for this ...
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1answer
39 views

What is the distribution of the number of heterozygotes in finite populations?

Consider a bi-allelic locus with alleles A and a. We denote the frequency of the A allele by ...
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2answers
79 views

Junk DNA and “random” mutations [closed]

I'm somewhat irritated by "mutation" generally being described as a fully random factor in evolution: pure randomness does not seem like something that can survive in a long evolutionary process. And ...
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17 views

Why is 2 sexes in an organism so common? [duplicate]

Sorry if this is a super simple question, but why do a lot of species have only 2 sexes? Some species just have 1 sex, but I've never heard of an organism having 3 sexes, for example. 3 sexes seems ...
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3answers
202 views

Why does all life use the same macromolecules in their genetic code?

There is no biochemical constraint of any sort, so why doesn't some other code work? Why is it specifically RNA/DNA?
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41 views

How octopus develops its imitation skill?

I've watched one documentary about a Mimic octopus which they can imitate another animals in several form e.g. a Lion fish, a Sea snake, a Flatfish, etc. My question is how these octopuses can have ...
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40 views

How did the double circulatory system evolve from the single circulatory system

I already learned how the mammal circulatory system (double circulatory system) evolved from the reptilian circulatory system. How did natural selection evolve the reptilian circulatory system and the ...
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116 views

Is it possible there were multiple origins of life? And, if so, why did the one which became the common ancestor between all organisms prevail?

I have learned that all currently-living organisms come from a common ancestor, which I theoretically understand. However, my professor in a class mentioned that there is a chance that there were ...
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0answers
56 views

Why do we turn darker in the sun? [duplicate]

I tried the all powerful google to answer this question - but I am not getting the answer I seek. I know we turn darker because the skin produces melanin. The question remains - why darker? I am a ...
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1answer
149 views

why didn't natives of south america evolve darker skin?

I understand that darker skin tone is caused by melanin which helps to protect against the extra UV radiation that comes from more direct sunlight. It evolved in Africa before we migrated away from ...
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45 views

How did the tendency to perform death rituals evolve?

Both elephants and humans perform rituals when deaths occur. However, I do not see any evolutionary benefit of this. The rituals take time, which apparently could be better spent hunting, foraging, ...
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122 views

Why didn't humans evolve to reproduce identical twins all the time?

According to the selfish gene theory, it seems like because identical twins sometimes get produced, a mutation to a gene that says, "if you have an identical twin, be fully altruistic towards them" ...
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2answers
271 views

How did zootoxins evolve?

I've always wondered how toxins in certain organisms have evolved. Particularly, organisms that produce toxins as a deterrent to predators as opposed to organisms that use it to paralyze their prey. ...
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1answer
72 views

How did people's liking of ceremonies evolve? [closed]

Habitual group activities are prevalent across many animal species, particularly in mammals, especially in primates. However, I do not see any evolutionary benefit of this. 'Ceremonies' take time, ...
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1answer
64 views

Extinction of species with extant descendants

From what I've seen, species such as Homo heidelbergensis which have extant descendants are classified as extinct, which makes sense as far as it goes. However, given that species exhibit a continuum ...
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1answer
25 views

Endothermy in different species

Birds and mammals are both endothermic, meaning they metabolically generate the heat they need to keep their body within a certain temperature ranger. But birds are closer relatives to reptiles than ...
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4answers
395 views

Is our genome decaying (see “Genetic Entropy”), and, if so, is this evidence for our genome being “young”?

In the book Genetic Entropy & the Mystery of the Genome the author says that the genome cannot be old because the genome is "decaying". Decay is a very subjective term, but in this case he means ...
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1answer
63 views

History: Do evolutionary and ecological processes occur at the same timescales?

Classically, it was thought that evolutionary processes occurred at a much slower pace than demographic/ecological processes. Nobody, ever thought about incorporating both processes into the same ...