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Questions tagged [sexual-selection]

The concepts of mate choice and competition over eligible members of the opposite sex in animals, including humans.

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Is there any evidence that sexual selection may lead to extinction of species?

Darwin suggested that sexual selection, especially by female choice, may counter natural selection. Theoretical models, such as a Fisherian runaway process, suggest that evolution of preference and ...
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Is there evidence that some non-human species perform sexual selection based primarily on intelligence? How do they do this?

I'm a biology amateur, but it seems like sexual selection is almost always performed based on physical characteristics, the outcome of physical contests, or some sort elaborate courtship. But do any ...
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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.
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Do men have more extreme variations than women?

This question was considered unsuitable for Skeptics and I think it is more suited to BIology than Cognitive Sciences I was reading this article which I found interesting. It is not supported with ...
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Why are not all species hermaphrodites?

If a hermaphrodite animal (like slug, snail, etc) finds a partner they can mate immediately. If another animal with "normal" reproduction (lets say a mouse) finds a partner they can only mate if they ...
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Why do we have more male infants born?

For every 104 male babies, we have 100 female babies and there are statistics which are more reliable. (Those tell us that we have 997 female infants born per 1000 male infants born.) What is the ...
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Why does sex last so long?

I wonder why (especially human) sex lasts longer than just a few seconds? My thought is that the shorter it takes a man to ejaculate, the lesser is the risk that he gets interrupted by a rival or a ...
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Why does sexual selection evolve beautiful features?

I have a very raw understanding of sexual selection: Say a group of females of a certain species "like" some feature of a certain groups of males; by "like" I mean some behaviour that makes this ...
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Why are men stronger than women?

What are the evolutionary explanations for why women are physically weaker than men (on average), and is this difference adaptive? See figure one here. I suppose that something puts pressure on men ...
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Why is the Kakapo more attracted to humans than its own kind?

The Kakapo can be seen in this video by BBC. It is said that the species is strongly sexually attracted to humans. Why could this be the case?
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Is there a mechanism by which mammals lose interest in a partner after mating?

I'm reading the book called "Cupid's poison arrow", which revolves around a rather simple assumption: most mammals, including humans have a genetic program that is responsible for ever increasing ...
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What is the relationship between sexual and natural selection?

In Evolutionary ecology: Novelty makes the heart grow fonder, they say: Thus, it seems that the diverse coloration in this species is promoted by both natural and sexual selection. I had always ...
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Is human “sperm warfare” a concept supported by biology?

I've recently read the "Sperm wars" book by Robert Baker. It deals with human sexuality and infidelity. The main premise of the book is that human male has different kinds of sperm: Regular sperm ...
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Are we more attracted to people of the same ethnicity? [closed]

Are humans more attracted to people from their own ethnic groups? I ask this because most of the time people have relationships with people of their own ethnicity, and I wonder if it's purely social, ...
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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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Do male animals visually perceive females as more/less attractive?

If we somehow remove pheromones, do animals experience a phenomenon similar to human "visual beauty" when looking at members of the opposite sex? For example, given a set of 20 female ducks observed ...
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Does any animal species have two sexes and more genders?

Are there any animal species that have two sexes and a kind of different internal diversification in two genders or more? I don't mean something like different-task-based diversity, but something ...
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1answer
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Is a female spider, well-fed by sexual cannibalism, less likely to mate again?

The Wikipedia page on sexual cannibalism (e.g. female spiders eating their mates) currently has a statement that sounds wrong to me, but I don't feel expert enough to edit it out: An additional ...
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Is sexual selection evolutionarily advantageous?

Our biology teacher says that peacocks will soon become extinct because of bigger and bigger (and heavier and heavier) tails. Why natural selection did not eliminate sexual selection?
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Why estimate linear and full (linear, quadratic, and correlational) selection coefficients separately?

"We then fitted a linear regression including all three life-history traits to estimate the vector of linear selection gradients, β, for each sex (Lande and Arnold 1983). A quadratic regression ...
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Is there a kind of 'rule' which decides whether the male of female is bigger?

In human race usually males are larger than females, and probably is this for all primates. But some animals there are the females bigger, but what determines whether the male or female should be ...
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Role of drift in evolution of sexually dimorphic traits

Is there a model for predicting how drift can affect the evolution of a sexually dimorphic (SD) trait? I've been trying wrap my mind around this paradoxical question; sexually dimorphic traits evolve ...
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Sexual selection in cats or other animals

I was wondering if you could answer some of my questions regarding sexual selection in cats (or any other animals). I would like to apologize beforehand for my incorrect term use. When it comes to ...
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Is the deep ocean fish look ugly because due to darkness there is no visual sexual selection? [closed]

Is the deep ocean fish look ugly because due to darkness there is no visual sexual selection? If so, is there a common notion of beauty between humans and animals?
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1answer
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Is there a distinction between the fisherian runaway theory and Fisher's sexy son theory?

In many websites/books they are referred to as part of the same process whereby: "runaway" describing that the process continues even after traits become maladaptive the "sexy son theory" explains ...
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Isn't heritability more important to genic capture than just genetic variance?

Rowe & Houle (1996) give two criteria for the selection of costly female choice: Condition dependence of sexually selected traits High genetic variance in condition Regarding heritability, ...
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Are there examples of selection on males influencing female phenotypes?

I've been studying selection on female body color in a sexually dimorphic species and am intrigued by the possibility that selection on males, whether it be through sexual or natural selection, may ...
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How is “selection” best defined?

There is natural selection but there is also sexual selection which some regard as a category of natural selection. There is also artificial selection (by humans). The question is, what is a most ...
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Advantages of bisexual reproduction over asexual one toward species promotion? [duplicate]

Are there any advantages of bisexual reproduction over asexual one towards species conservation and promotion? Do animals that have two or more sexes have more chances to reproduce? Does anybody had a ...
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1answer
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Can sexual selection operate in temperature dependent sex determining organisms?

Or more broadly, are distinct forms of genetic inheritance (ie. sex chromosomes) needed for sexual selection? My thinking was that since there are no sex determining loci, there could not be linkage ...
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Does unequal dominance mean the X-chromosome should be a coldspot for antagonistic variation?

Sexually antagonistic genetic variation, in a simple model, will persist if the benefit to one sex is (near) equal to the cost in the other, otherwise the polymorphism will be selected out of the ...
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1answer
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Is the golden ratio of anatomic measurements universally beneficial for sexual reproduction? [closed]

It is often claimed, in popular media, that the golden ratio (Fibonacci series) in for example some face measurements is aesthetically (and hence reproductively) attractive with respect to the humans. ...
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In what animal species is the sex ratio skewed in favour of the fertile female?

Ants have something like a single fertile female to several males. The same applies to bees, and larger animals - elephants too. Is the sex ratio universally skewed in favour of the female? What ...
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1answer
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Is mate choice in non-human primates MHC-dependent?

Whether the major histocompatibility complex (MHC) affects or not mate choice in humans seems mired in controversy at the moment. Without implying that looking at non-human primates would solve this ...
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What is genodiversity good for?

I saw some documents which were trying to say that they can prove via sweat smell selected by women that humans are developed to find a partner with similar genes. At the first glance, I refused it as ...
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1answer
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Do gibbons have a monogamous sexuality?

the question is already in the title. If possible, it might be extended to: Have animal taxa (mammal) who tend to live in a family structure have a monogamous sexuality? Or are there cases of these ...
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1answer
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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 ...
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Follow-up to The Red Queen by Matt Ridley? [closed]

I just finished reading The Red Queen: Sex and the evolution of human nature by Matt Ridley. Since this book is over 20 years old, I was wondering if more recent research made part of the book ...
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Why can't men produce milk, just like women? [duplicate]

This might seem a bit weird, but why can only women produce milk? Wouldn't it be more beneficial to our species if all humans could produce it? I can't think of any reason only one gender would need ...
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Are there any mammals in which polyspermy produces viable zygotes?

Are there any mammals in which polyspermy produces viable zygotes? In the wikipedia page it is mentioned that there is a delicate equilibrium between female defenses against many sperms, which ...
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2answers
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Why would a human female have a sexual display despite male biased operational sex ratio? [closed]

why would a human female have a sexual display despite male-biased operational sex ratio? In human society there is a male-biased sex ratio, due to female child rearing, which results from anisogamy. ...
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Isn't sexy son hypothesis circular?

Sexy son hypothesis. It states that females are attracted to certain traits in males, because these traits will be attractive in her sons either. But isn't this circular? Like "I'm attracted to that ...
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1answer
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Does sperm weight causes sex ratio?

Chromosome X in female sperm is heavier than male Y chromosome. Does it causes difference in fertility of sperm and heavier female sperm is unable to fertilize better than male sperm? This is given ...
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1answer
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Why some traits are more desirable in the sexual selection?

For example, why do peacock females choose males with the biggest tail? If there is no advantage in such tail.
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1answer
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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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1answer
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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 ...
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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.
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What are the 2 general systems to understand the whole natural world? [closed]

In Graham Bell's book Selection, it's written: To some it may be a cause of regret that the natural world cannot be understood in terms of a single set of rules and laws, but at least, so far as ...
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Why does female's age of puberty inform on mating system?

Reading from Does increased calorie intake cause increase in libido in humans?, @AlexStone says: I'm aware that humans have a dual mating strategy - somewhere between pair bond and casual mating. ...
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Evolution of sexually concordant genetic variation on the X-chromosome

It was theorised in 1984 that sexually antagonistic genetic (SA) variation should more easily evolve on the X-chromosome. This is partly because female beneficial/male deleterious mutations face less ...