Tagged Questions

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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7
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4answers
312 views

Extinction of species

I barely know anything about biology and realize that this might be a stupid question, but I'll ask anyway! I know that species "transform" into other species through the process of evolution. Many ...
2
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3answers
92 views

Is there an evolutionary purpose to armpit perspiration?

Given that most Americans seem to do fine using anti-perspirant, it got me wondering: is there an evolutionary purpose to underarm perspiration? I can't imagine it acts to attract the opposite sex. ...
0
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2answers
74 views

Questions about the Evolution Theory [closed]

I'm trying to understand more about evolution theory. (I am coming from a mathematical background) What i understand till now is that the "improvement" of the dna is a purely random development and ...
2
votes
2answers
52 views

Conservation Genetics - Book recommendations

Can you please give me some advice for a book in (evolutionary) conservation genetics that offers an in-depth review of the mathematical formulations used in this field. I read the book Evolutionary ...
6
votes
3answers
370 views

What exactly does adaptive mean?

This is a quote from Dey et al 2014: Hatching asynchrony is thought to be adaptive because... What exactly does adaptive mean here? Does it mean hatching asynchrony has fitness benefits? Or does ...
2
votes
0answers
59 views

How to track and describe the evolution of a gene?

So I have a project student (undergraduate) who has been assigned a project to study the evolution of a gene (and possibly related genes) through species. I am not an evolutionary biologist, and hence ...
0
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1answer
29 views

Periods of Heavy Speciation

I have a set of microRNA ages with corresponding labels suggesting which clade they first emerged from. For instance, for hsa-mir-1, let's say, it would have an age of Eutheria. I have several peaks ...
7
votes
1answer
69 views

Why do Mangoes have a single large seed, and not multiple small ones?

I was just thinking about this, wouldn't it make more sense for a mango to have multiple seeds, as it would allow more seed propagation?
1
vote
1answer
30 views

Does documentation exist that shows the evolutionary connection between common horses and the okapi?

I'm trying to put together some documentation on the relation between the common (modern) horse and the okapi. I've found a tree that shows that connection but it has no references. I'm hoping that ...
5
votes
1answer
72 views

Gender and age-specific mutation rate in plants

Background General concept According to Cochran and Harpending (2013), mothers transmits on average a number $x$ of new mutations to their offspring. This number $x$ is independent of the age of the ...
3
votes
1answer
54 views

Horizontal gene transfer versus convergent evolution

There are several often noted examples of convergent evolution (eyes, bat/bird wing evolution etc.) How do we rule out horizontal gene transfer in these cases?
2
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3answers
98 views

How did the horned lizard evolve?

It's a lizard that has the ability to burst blood vessels in it's eyes and shoot blood as self defense. How can this behavior be explained evolutionary? Wouldn't it mean that there had to be some ...
21
votes
5answers
2k views

Why are there species instead of a continuum of various animals?

As I understand it, various animal traits have to evolve gradually, but what happens to the species that are "neither here nor there"? To put it differently, if a species evolved from another, it did ...
2
votes
3answers
208 views

Where are the evolutionary “inbetweeners”? [closed]

The problem I've always had with evolution is the actual lack of variation between animals. More specifically, the lack of observable gradual change between species. Take for example the hammerhead ...
5
votes
1answer
102 views

Lost Ability to Regenerate Body Parts during the Transition from Amphibians to Mammals

Why have higher-order animals lost the ability to regenerate body parts during evolution? Wouldn't it be better for survival? What is the evolutionary theory behind it?
3
votes
0answers
55 views

Intuitive explanation for Kin- and Group- selection

It is known from theoretician in the field of kin selection that kin selection (inclusive fitness theory) and group selection are actually two sides of the same coin. In other words, these two ...
7
votes
2answers
499 views

Which phylum appeared most recently

I'm aware that our earliest records of many major animal and plant phyla come from the Cambrian or Precambrian periods, and I'm also vaguely aware of some of the objections raised with general concept ...
2
votes
1answer
39 views

How did the Chromosome #2 Fusion propagate?

There is strong evidence that chromosome 2 in humans is a fusion of two chromosomes of a common ancestor of chimps and humans as explained at wikipedia here Was it necessary for the common ancestor ...
1
vote
1answer
68 views

Do species which have a closer common ancestor to humans tend to be more intelligent?

Q: Do species which have a closer common ancestor to humans tend to be more intelligent? Our closest living relative, the chimpanzee, seems to be regarded as intelligent: Chimpanzees make ...
2
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0answers
44 views

Odds of Fusion of Chromosome #2

There is strong evidence that chromosome 2 in humans is a fusion of two chimp chromosomes (i.e. common ancestor of chimps and humans) as explained at wikipedia here The question is what are the odds ...
3
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1answer
133 views

Soft and Hard selection

Seems to me that these two sources (M. Whitlock, B. Wallace) use different definitions of soft and hard selection. M. Whitlock: Soft selection occurs when the relative fitness of an individual is ...
3
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1answer
451 views

Why are men stronger than women?

What are the evolutionary explanations for why women are weaker than men (on average), and is this difference adaptive? See figure one here. I suppose that something puts pressure on men to be ...
4
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1answer
104 views

Are there any cases of observed extreme speciation [closed]

Is there an observed (direct not indirect) speciation on record showing a species shift within the span of history of recorded science?
5
votes
3answers
136 views

Theoretically, is domestication of (virtually) any animal possible?

Looking at ones that manage well alongside us human animals, such as dogs and cats, we see that this is possible for evolved, distant animals to have heritable, preferable traits around people. ...
1
vote
1answer
77 views

Has any creature ever devolved to be cold blooded? [closed]

Is this even possible? Because I have a non-scientific gut feeling that it is irreversible. Whales and dolphins are evolved from land mammals, and they've remained warm blooded while it doesn't give ...
1
vote
0answers
71 views

Can human change its morphology or anatomy due to ecological changes?

According to Charles Darwin, as the surrounding environment changes, so changes the anatomy or morphology of a specific organism. But nowadays, humans have become very advanced in the technology and ...
2
votes
1answer
84 views

Senescence, immortality and evolution?

Many have heard about the fabled "immortal" jellyfish, Turritopsis dohrnii, which doesn't die from aging (senescence) and can revert the aging process indefinitely. It is rather remarkable that only ...
1
vote
2answers
137 views

On evolution statistics [closed]

This basic evolution theory question has been haunting me since childhood and I'm kind of embarrassed that I can't explain it yet: Consider a butterfly. It's wings have evolved to look like the eyes ...
2
votes
2answers
96 views

What is doubling of genetic material invented in flowering plants?

David Attenborough in his Kingdom of Plants 3D said, that flowering plants made two inventions: (1) doubling of genetic material and (2) symbiosis with animals. What was meant by "doubling of genetic ...
6
votes
1answer
137 views

A question about the intersection of evolution and thermodynamics

From this 2014 article in Quanta magazine by Natalie Wolchover there is a quote from a physicist with an intriguing idea about evolution: “You start with a random clump of atoms, and if you shine ...
1
vote
1answer
73 views

Why are hens so different from other birds? [closed]

Hens lay many eggs during their lifetime (at least, I don't know of one which can lay more eggs) and they can't fly. Compared to other domestic animals it seems to me they are the least capable of ...
0
votes
0answers
45 views

Does healthcare and therapy affect natural selection adversely? [duplicate]

In the last 200 years or so, healthcare and therapy has been revolutionized. Mortality rates are going down everywhere. Even if the disease is terminal, medicine can prolong life for quite a while. ...
5
votes
3answers
174 views

Why are there no tree-like plants that grow in lakes?

Looking at aerial photos of boreal forests, with dense woods clear-cut by quiet lakes, I wondered why exactly are the woods so clear-cut at the edge of water? Why won't trees develop adaptations that ...
10
votes
2answers
268 views

Have we ever observed two drosophila lineages that evolved reproductive isolation in labs?

Background The standard definition of species refers to the concept of reproductive isolation. If two lineages are found to be reproductively isolated, then we consider these two lineages to belong ...
1
vote
1answer
34 views

Assumptions of the models for haploid and diploid selection

For a bi-allelic locus, the model for haploid Natural Selection is: $$\frac{dp}{dt} = \frac{pW_A}{pW_A + (1-p)W_B}$$ , where $p$ is the frequency of the allele $A$, which relative fitness is $W_A$. ...
2
votes
1answer
44 views

$F_{ST}$ when considering a multi-allelic locus

Sewall Wright defined the $F_{ST}$ in a metapopulation as being: $$F_{ST} = \frac{\text{Var}(p)}{\bar p (1-\bar p)}$$ , where $p$ is a vector of frequencies of a given allele and $\bar p$ and ...
1
vote
0answers
43 views

$F_{ST}$ and the genetic variance in metapopulations

From this video (21'15''), the speaker gives the following formulae in order to calculate the between and among populations genetic variance from the $F_{ST}$: $$V_{Among Pop} = 2 F_{ST}V_G$$ ...
5
votes
5answers
142 views

What are some examples of evolving networks in biology?

I'm a master student working on networks analysis in general. A network is something that has nodes and there are links between the nodes. Nodes and links could have attributes. An evolving network is ...
3
votes
4answers
193 views

Bad Eyesight and Evolution

Why do many humans have bad eyesight, such as near-sightedness, which hampers performance in a wide variety of tasks? Shouldn't there be evolutionary pressure towards better eyesight?
1
vote
1answer
84 views

What is the evolutionary reason behind human preference for salty foods?

It's been established that food palatability is related to it's caloric density. This hypothesis is used to explain why humans are partial to sugar and fat. But it is also said that humans are partial ...
2
votes
1answer
319 views

What is the difference between these terms: clade, monophyletic group and taxon?

Wikipedia definitions for these terms are pretty similar: http://en.wikipedia.org/wiki/Clade http://en.wikipedia.org/wiki/Monophyletic_group http://en.wikipedia.org/wiki/Taxon They sound like the ...
1
vote
1answer
40 views

Distribution of fitness in wild populations

If I get out in the wild observe wild populations and measure the distribution of fitness $f(w)$ in a given population. What will I find out? Will I observe a Gaussian distribution, a Poisson ...
1
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1answer
47 views

What is a sex-biased gene?

How do you define a male-biased gene and a female-biased gene as they are found in the abstract of this article.
2
votes
1answer
57 views

Definition of Sexual Selection?

How do you define Sexual Selection (SS)? (One might want to subdivide SS into intra- and inter- SS to answer) Is SS clearly different from Natural Selection (NS)? Is SS nested within NS or are NS ...
15
votes
3answers
3k views

Were there any flying dinosaurs?

I've seen some articles which came in contradiction with each other. The first article was talking about flying dinosaurs, dinosaurs with feathers and so on. A couple of other articles are talking ...
7
votes
2answers
296 views

Help with the Price equation

The Price equation describes mathematically the evolution of a population of units from one generation to the next. $\bar{w}\Delta \bar{z}$ = $Cov (w_i,z_i) $+$ E(w_i\Delta z_i)$ I would like ...
2
votes
1answer
99 views

What is the evolutionary cause for various finger lengths?

Why are the lengths the way they are with middle finger the longest?
1
vote
1answer
53 views

Various Genetic Loads and their Definitions

In population genetics, we talk about several types of genetic loads (also called just loads). I am asking for a exhaustive list and a short definition. Here are for example some genetic loads that ...
2
votes
1answer
82 views

Two-fold cost of sex and r/K selection theory

This article cites a bunch of articles (I haven't been through them) that the effect of the two-fold cost of sex is "reduced" in stable environment or in K-selected environment. It says: [..] the ...
1
vote
3answers
331 views

Why do our eyes close when we sleep?

Why do our eyes close when we sleep? Is it to relax our eye muscles? How can it be explained from an evolutionary point of view?