(CLO) New research published in the journal Biology Letters reveals that men are evolving with significantly increased height and weight, twice as much as women, increasing the level of sexual dimorphism, the physical difference between men and women.
“With improvements in living conditions at the national and generational levels, as environmental stressors decrease, male height and weight become twice as high as those of females, increasing the degree of sexual dimorphism,” the researchers wrote in the paper.
In nature, sexual dimorphism is common, where one sex is larger or more distinctly different from the other. For example, male lions are larger than female lions, while in some species, including some spiders and anglerfish, females are larger than males.
Illustration: GI
Traits in males that increase mating success, such as bright coloration or large body size, often evolve due to female selection or male competition, evolving because females prefer them or because they help them against other males.
Dimorphism may also have evolved from different survival strategies between the sexes, such as females needing better camouflage for nesting.
In humans, men are on average taller and stronger than women, which may stem from competition between men for status, resources, and mates. As a result, these traits are often found more sexually attractive by women.
“This is why men judge the formidableness of potential rivals using physical cues, such as upper body strength, and women find tall, muscular men with relatively large total body mass (but not obesity) particularly attractive,” the researchers wrote.
However, to achieve these traits, males face high evolutionary costs, as they must eat a lot and also be physically healthy throughout childhood and adulthood to achieve and maintain such traits.
In the modern context, the availability of food and the ability to avoid disease have facilitated the development of these superior traits in men.
Based on data from the World Health Organization (WHO) and analysis of 135,000 people in 62 countries, researchers found that as the burden of disease decreased, men's height increased twice as fast as women's.
The team concluded that more favorable social and ecological conditions not only increased human height and weight but also increased sexual dimorphism.
This reflects that male physical development is more sensitive to the living environment than female, especially in terms of morphological characteristics such as height and weight.
Ngoc Anh (according to WHO, Biology Letters, Newsweek)
Source: https://www.congluan.vn/nghien-cuu-nam-gioi-ngay-cang-tien-hoa-to-lon-hon-nu-gioi-post331562.html
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