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Sexes (male and female) are generally defined in terms of Anisogamy, which means that there are size differences between the gametes (i.e. the reproductive cells that fuse at fertilization). The sex with smaller gametes is defined as male and the sex with larger gametes is defined as female, and individuals that can produce both types of gametes are called ...


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I searched for "chimpanzee strength" on PubMed and followed links from O'Neill et al. PNAS 2017 "Chimpanzee Super Strength and Human Skeletal Muscle Evolution" to Bozek et al. PloS Biology 2014 "Exceptional evolutionary divergence of human muscle and brain metabolomes parallels human cognitive and physical uniqueness" where I found this figure: which ...


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Yes, you nailed it! Adam's apple (aka. laryngeal prominence) exist in both men and women. It is a piece of bony cartilage called thyroid cartilage that wraps around the larynx (aka. voice box). The Adam's apple is more prominent in males because males have have a bigger larynx (giving males a deeper voice). In males, the prominent Adam's apple typically ...


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Selection in one sex can produce a correlated response in the other when there is pleiotropy (or linkage disequilibrium) (see Lynch & Walsh 1998, and Lande 1979 & 1980). Genes can be considered pleiotropic when they affect more than one trait, for example; the male and female forms of equivalent traits, and this can be seen as covariance between the ...


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I assume by asking why, you are asking about the distal evolutionary causes, and not the molecular mechanisms that account for these things. (Important disclaimer: these causes are difficult to be certain about; they require a fair amount of informed speculation.) With that said: it is widely agreed upon in evolutionary biology that human males, as in ...


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We seem to have a preference for proportionally longer legs (see comment here for a good summary around that study). So when you are observing "pedestrians" they have probably tended to dress and comport themselves to skew your perception of their leg lengths. Perhaps in your cultural environment females have a greater capacity and/or motivation to alter ...


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There are very few studies about the gender-based differences in response to food deprivation in humans (or at least I didn't find many such reports). In one of the papers, Sodersten et al conducted a research on 30 (17 women and 13 men) high school-aged subjects. After a short-term fast (skipping 2 successive meals), males consumed much more food while ...


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More details to support @SPr's answer, from the abstract of Plavcan (2012): "Sexual Size Dimorphism, Canine Dimorphism, and Male-Male Competition in Primates: Where Do Humans Fit In?" While dimorphism in primates is associated with agonistic male mate competition, a variety of factors can affect male and female size, and thereby dimorphism. The causes of ...


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In sexually dimorphic ant-mimicking spiders, it depends on the specific species which sex resembles the ant most (Cushing, 2012). In many cases of sexually dimorphic spider myrmecomorphs, the male is more mimetic than the female, such as in Corinnidae species and the genus Castianeira, Oonopidae and Antoonops. Such sexual dimorphism may be adaptive if the ...


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The female mammary gland tissue contains androgen receptors (testosterone is an androgen). So this tissue is sensitive to androgens, and they inhibit the estrogen-induced proliferation. The inactivation of the androgen receptor on the other hand leads to an accelerated growth of the pubertal mammary gland and to the upregulation of estrogen receptor α ...


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[C]an drift overcome sexual selection in the evolution of sexually dimorphic traits? Short answer Yes Long answer There are many ways to consider the effect of genetic drift. Here is one: One can approximate the probability of fixation of new mutations (using diffusion equations) with $$P_{fix}≈\frac{1-e^{-4Ns} }{1-e^{-4s}}$$ , where $s$ is the ...


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It comes down to investment in offspring. Males invest little in offspring only a little sperm whilst females have to develop the more expensive egg and the energy used through its development. In the mammalian line, this investment has increased in amount, initially through viviparity and then through the secretion of feeding fluids. In species, such as ...


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Yes. Dewing et al. (20030 found that gene expression in mouse brains differs between male and female mice about 10.5 days after the mice had sex. This occurs before hormonal contributions to brain development. They identified about 35 genes that were appeared to show preferential expression in the female brain and another 16 that appeared to be show ...


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If you're asking if humans are a sexually dimorphic species, the answer is "yes". If you're asking based on the viral response of the science teacher, then the answer is still, "yes". What is described above are chromosomal abnormalities, or other disorders of development, but they are still describing sexual dimorphism in the phenotype. However, the answer ...


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There are two common explanations both are difficult to demonstrate. I personally favor the former but I will not claim it is the only explanation. selection starts as either a random occurrence or as some initially beneficial trait (a slight increase in tail length may have been beneficial originally) Then runaway selection takes over. Any increase also ...


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Here's a study comparing performance in swimming. Before age 8, there's no difference; from age 11-12, there's some small difference, after age 13, there's a large difference. https://www.eurekalert.org/pub_releases/2012-05/iu-wsg052512.php


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I would say that anisogamy, the different gametes such as sperm and eggs, is itself, a form of sexual dimorphism. However, you've since stipulated that you want to know the prevalence of sexual dimorphism beyond sex organs/gametes. Sexual dimorphism occurs in a vast plethora of traits, at a variety of levels, and in almost all known dioecious species. It ...


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In general, It's pretty much the reproductive cells with plants and animals. The male's unique cells (sperm, pollen) fertilizes the female's unique cells (egg, ovule). The resulting offspring develops and hatches from within the female's egg/ovule. Now whether that egg/ovule stays put, gets ejected, hides in a flower, or transferred to the male (like your ...


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Sexual dimorphism evolves, as you suspect, via natural selection, specifically sexual selection (which I view as a form of natural selection). Genetic drift, by definition, is random. Random changes of allele frequencies are extremely unlikely to lead to the consistent evolution of phenotypic differences between males and females. Sexual selection on the ...


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As very well explained also in Wikipedia https://en.wikipedia.org/wiki/Sexual_selection_in_birds , visual signaling is only one of the way birds uses to pick a partner, olfactory and acoustic signals also play a major role.


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You can answer this question for yourself using the modMine data warehouse for modENCODE datasets. All you need is a list of female-specific genes (using your identifier of choice, although FlyBase FBGxxxxxxxx are the simplest). You can use their list tools to upload your own list of identifiers, and then there are a bunch of widgets that will tell you ...


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There are some similar resources, which at the same time do not mix the ingredients in the same way as your tool. Hope that pointing out the respective differences will help your rebuttal or resubmission! e.g.: A similar web service is part of flyrnai, where tissue-specific expression can also be compared based on sex, and genes can be queried by the ...


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There is a big body of literature in one specific instance of fasting: Ramadan. While not as nicely controlled as most fasting studies there certainly have been a lot of parameters investigated and if there are any differences between men and women. A quick Google scholar search unearthed this article by Finch et al. with the following in the abstract: ...


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There doesn't seem to be anything wrong with the paper, but as pointed out in the comments (and in the press release itself), the study was small, so any conclusions should probably be tentative. Adding a little more detail from the link: For the study, which was very small, researchers recruited nine young males and 9 females, all roughly in their mid-...


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"has human intelligence evolved as a costly male signal which has, over time, been passed to females too, but whom are just not as interested to use it to attract mates?" (I am ignoring that last part) So you suggest intelligence (the modern human brain) evolved solely as a sexual dimorohism which then migigated over time? I find that particular ...


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Male and female pupae are consistently slightly different sizes. This isn't particularly obvious to look at them, but allows them to be sorted mechanically by using two sheets of rigid, waterproof material (aluminium, glass or acrylic) fixed at a slight angle to each other, and washing the pupae down between them until they get stuck. The pupal sorter in ...


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Your first definition is correct: a homologous trait is one that can be mapped unambiguously between two samples. What establishes the homologous relationship depends, of course, on the trait or feature being mapped. For example, one way sexually homologous traits can be identified is by tracing the physical development of a male vs. a female organism. If ...


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