Subversive research on mammals: Females are larger than males in most species

It overthrows everything we know about them, as it proves that most species are larger than males. Research writers argue that prejudices in scientific literature, which have existed for over a century, may have led to this misunderstanding for females and male mammals. Differences in physical size between male and female individuals of the same species vary in mammals depending on competition for mates and how parents invest in their offspring. Although research in the past has identified that males and females of the same size meet surprisingly often, the general account was that males are larger than females in most mammals. Researchers compared the body mass of males and females from 429 species in nature. In most cases they found that males were not larger than females and that in many species both sexes are the same size. For example, male and female lemurs, horses and zebras are usually of similar size. A smaller percentage of species showed large differences in body size between the sexes, such as the northern hemisphere sea elephant, where males are three times larger than females. Writers argue that the reason for the narrative of the larger male may be due to prejudices in research around charismatic and basic species with larger males, as well as research on male competition for mates, as in primates and seals. However, rodent and bat species, which are a much larger proportion of mammals, have less frequent differences in body size between the sexes. Typical is that about half the bats have larger females. They also note that their findings may change, as more data on mammalian physical sizes is collected in the future and recommend more research on the biology of females in all species.