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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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
97 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 ...
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0answers
24 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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5answers
1k views

Why do men have nipples?

I'd be tempted to call nipples in men vestigial, but that suggests they have no modern function. They do have a function, of course, but only in women. So why do men (and all male mammals) have them? ...
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26 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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2answers
281 views

What are evolutionary implications of contraception and reduced childhood mortality rates worldwide?

I've heard the following idea this morning: Before the introduction of contraception, humans conceived quite a lot of babies (there was little to do to avoid that), but the population was kept in ...
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3answers
111 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 ...
6
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2answers
465 views

Why aren't we ambidextrous?

It seems so simple that if my brain can tell my right hand to do something, then it should be able to tell equally well to the left ? This seems like a pretty major evolutionary advantage. Why haven't ...
3
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1answer
68 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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4answers
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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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1answer
72 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 ...
2
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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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65 views

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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42 views

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 ...
3
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1answer
222 views

Is greed an evolved trait?

I am not a biologist, but I am fascinated by evolution. I was watching the news this morning and, as so often is the case, there was a news story about a corrupt politician who was accepting ...
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1answer
52 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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2answers
441 views

How is menstruation not suicide in the wild?

Watch any wilderness special for more than a few minutes, and you'll notice a familiar pattern: when a predator catches the scent of blood on the wind, the hunt is on. Wounded animals make the best ...
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1answer
46 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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9answers
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Why didn't the polar bear change its color from white to black during evolution to absorb heat?

Polar bears are white in color and white color is not a good absorbant of heat. Why then didn't they evolve a black color to absorb more heat?
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0answers
57 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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2answers
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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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1answer
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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2answers
684 views

Do plant-animal cross races exist?

Plants and animals have the following distinct properties: Plants live from solar energy by photosynthesis, they use solar energy to make sugar and oxygen out of carbon dioxide, which gives them ...
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2answers
2k views

How and why did mammals go back to the oceans?

If I understand evolutionary biology correctly, mammals first evolved on land as small, rodent-like creatures, in a time when reptiles were dominant on land. Eventually, they diversified into the ...
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2answers
281 views

Why, specifically, does each generation, on average, improve upon the design of the species rather than degrade it?

In every non-life example I can envision, a copy of a copy is always a degraded or less pure version of the original unless some outside influence acts to correct the copy back toward the ideal ...
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3answers
677 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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4answers
1k views

Why did life not evolve to use radio?

We use electromagnetic communication everywhere these days. Cell phones, wifi, old-school radio transmissions, television, deep space communication, etc. I'm curious about some of the possible ...
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1answer
49 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
50 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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452 views

What is the viability of Intelligent Design as a supplement to chemical abiogenesis and Darwinian Evolution?

First of all I am not endorsing Intelligent Design (Wikipedia link); I'm asking this because I (someone who does not have a background in biology, organic chemistry, or philosophy) got into a ...
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1answer
52 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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2answers
137 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 ...
2
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2answers
183 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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0answers
35 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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2answers
189 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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4answers
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Why are there no organisms with metal body parts, like weapons, bones, and armour? (Or are there?)

Reading this question, Why are there no wheeled animals?, I wondered why no organisms seem to make use of the tensile and other strengths of metal, as we do in metal tools and constructions. I am ...
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1answer
50 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
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 ...
2
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1answer
76 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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3answers
14k views

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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3answers
187 views

Why do human ears have a lower boundary for the lowest energy perceivable signal than eyes?

I am currently hearing a lecture about human machine interaction. The lecturer is not a biologist (neither am I, we are both computer scientists), but he makes some statements about biology which I ...
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3answers
107 views

Book recommendations for evolutionary models

I was recently working on getting a statistical model of a DNA sequence. To do this I found that understanding evolution quantitatively seems to be quite important. I would really appreciate any book ...
3
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3answers
100 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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0answers
37 views

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 ...
0
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1answer
106 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. ...
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?
3
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1answer
194 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?
0
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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 ...
3
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7answers
555 views

Introductory books about evolution

This days I read some debates on evolution. That made me more interested to read something reliable on topic - I mean books. I'm christian - although I think it doesn't matter on that topic - and I ...
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2answers
340 views

Why are there so many medicinal plants?

Here is wikipedia page containing a list of plants used in herbal medicine. One might first want to argue that many of them actually do not have any medicinal/beneficial effect on heatlth. I think we ...