In the process of sexual selection, how did the partner develop a preference for a certain feature?

The biological species concept states that a species is one or more actually or potentially interbreeding populations. It is indeed what we observe in nature. We don't see individuals of different species just mating randomly with individuals of any species out there. Even closely related species, such as the coyote and the gray wolf, for example, remain separate species, even though occasional hybrids can be found. There is a very good reason for it. Interspecific hybrids, in most cases, are less well adapted to the environment than either parental species. Wolves, for example, hunt in packs, but coyotes are lone hunters. A wolf-coyote hybrid, or coywolf, which is bigger than a coyote, but smaller than a wolf, would be ill suited to life in packs. Being smaller, the coywolf will most likely be picked on constantly by every member of a wolf pack, to the point that they have to leave to lead a solitary life, as many omega wolves (the lowest ranked wolf) often do. Being bigger than a coyote, a coywolf would need to eat more than a coyote and spend more time hunting, but at the same time it is unable to hunt as a part of a pack, so it cannot bring down large game on its own. A coywolf therefore is not as well adapted as either the coyote or the wolf. Therefore nature has evolved many ways to facilitate the identification of conspecific individuals so as to minimize interspecific hybridization. Scientists call these reproductive isolation mechanisms.

That means individuals of a species need a way to identify other individuals of the same species to prevent interbreeding. Many species use visual signals. For example, a bird may have a patch of red coloration on its body to identify it as species A. Females who see the patch of red are reassured that they have met the same species, sometimes perhaps with the additional aid of a species-specific bird song. Therefore it is the brain that is being excited by these signals. The brain has a tendency to react to strong signals. It is called a supernormal stimulus. For example, many birds that nest on the ground have an instinct to retrieve objects that look like an egg but is not inside the nest. Some birds have shown that they prefer to retrieve large eggs, since large eggs have more yolk and the young will hatch into a bigger nestling bird. So it makes sense to prefer large eggs. However, some birds have been shown to prefer super-sized egg-shaped objects over smaller eggs that are their own.

Given such tendency, it is not surprising that animals will also react to species identification signals the same way. They tend to react strongly to strong signals. Males of a species of Australian beetle, for example, look for large and orange objects, because the females are large and orange. It was soon found that some males prefer a particular beer bottle over real females, because the beer bottles are larger and more intensely orange than the female beetles.

That said, I am not sure that a hairless female body is the product of sexual selection, because we evolved on the savanna, where there is virtually no shade, and where we need to lose heat as quickly as possible by sweating. Hair reduces that efficiency. That is probably the reason why we have evolved a largely hairless body. Nevertheless, the naked body may then serve as one of the many species identification signals by humans because our closest relatives have hairy bodies. Nevertheless, European men seem to have re-evolved more body hair because of adaptation to a cold climate, but European women lack body hair except for the limbs. They have evolved a thicker layer of subcutaneous fat than men, so sexual selection may have kept women from re-evolving hair in places like their chest and abdomen in cooler climates. Sexual selection, however, almost certainly did not cause the human body to evolve hairlessness initially.

The need to identify individuals of one's own species may result in the appearance of seemingly inexplicable preferences among some species for seemingly maldaptive features, such as the male peacock's tail and, to a lesser extent, the male chicken's tail and head comb. They may have evovled initially to facilitate the identification of conspecific indivduals in order to avoid interspecific hybridization, but these signals may have become exaggerated over time through sexual selection because of the animal brain's susceptibility to supernormal stimulus. Perhaps sexual selection is nothing more than species identification signals working in conjunction of supernormal stimulus.

Often it is random; that is, a female who prefers a male with a feature that is only possible with exceptional health will produce offspring that are more likely to survive. For example, male peacocks with the most beautiful tail, a bower bird with the most elaborate bower, a red-winged blackbird with the reddest shoulder patches, etc.

Of direction, sexual PREFERENCE (now not sexual orientation) develops through the years. A few years in the past, I additionally favored petite men; now, I typically like muscular guys. However, I do not feel sexual ORIENTATION is a later-in-lifestyles built fine (good, I can simplest talk for myself, now not ALL persons; might be SOME persons are unique). For me, sexual orientation used to be now not, as you declare, a "built" fine. Ever because my earliest lifestyles reminiscence (four years historic) of whatever mostly, I've consistently overwhelmed on boys or even spotted, earlier than I even knew the phrases "homosexual," "bi," or "instantly," that I on no account overwhelmed on ladies. One might additionally seem at it like this. A sexual orientation, or loss of one, IS a built fine, a fine that develops in utero; and, because GENES straight affect the brain and psyche, then sexual orientation is, by means of extension, mental (genes --> psyche, psychogenetic). I'd be very interested to know the way you KNOW the mechanism through which EVERYONE's sexuality involves being by means of READING a few historical past?

Preference for less body hair is not necessarily related to genetics. It could be an acquired psychological trait. If one's first partner had little body hair that could affect preference. It's also a cultural thing. Warmer climes tend to see more skin left bare because less hair is needed.