This distribution of trait which suggests the need to grow so intense at certain points, where as the northerners with mutations with straight hairs had more children. So this argument goes on little further and based upon this principle that straight fibres facilitates better UV when compared to the curly hair which facilitates.  Then the study explored further that the UV light passes through straight human hair in its roots in a manner which is similar to the way like the light which passes through the fibre optic tubes. Some people argue against this because the straighter hair which ends tending to the downwards point and while fibre optics requires the light to get transferred in its roots and it could successfully enters the hair follicle and it got transmitted down the shaft. Also the argument went on further and they hindered by the curvature at the basement of the hair. So the skin which got coupled with the amount covered by long head hair seems that the people in the northern latitudes have adaptive usefulness of straight hairs. Apart from this argument they also conclude that the UV light radiation is poorly reflected upon soil and dull like surfaces.  Then they suggest that only light from the ground which get reflected will be passed through the hair follicles.

       Late after when they left Africa their skin had developed the ability of producing Vitamin D which enhances the bone strength and development. And it also enhances the ability to withstand the skin from UV light. So in those regions, the UV light radiations were too weak to penetrate the skin in the northern regions and it felt quite weak to penetrate the dark pigmented skin and for the for the early migrants in order to provide them enough D vitamin for the healthier bone development. Whereas especially for women’s, pelvic area of malformed bones are deadly dangerous in those days and it interfered with the successful delivery of babies and it leads to the death of both mother and infant during the time of delivery. Hence then situation prevails that women’s with the lighter skin survived more than the darker one and had more number of children than the darker one’s because their skin allowed to penetrate more UV light for the production of more vitamin D which makes bones stronger. So according to the jablonski’s theory that the straight hair texture need for Vitamin D which triggered the transition from dark skin to lighter one.

           Further some interpret the ideas of that scientist about some traits about the human hair structure. So these set of scientists came to an argument that Darwin’s explanation was about the sexual selection of about such traits. But when coming into the consideration of this triviality of human value judgement, whether physical traits were really adaptive for humans. But this sexual selection theory was not really a success as it was taken as the indication and this was taken as primary casual factor. So in this trait, the result of human preferences intended the pervasive expression of hair structure and it was fairly a random structure. It is been proved that anatomically modern humans arose approximately 200000 years old. It is being proved by the recent single origin hypothesis and anatomically the modern humans born in east Africa and they were called as Homo sapiens. Then later the study detailed about their migration. After approximately 15000 years later, modern humans migrated from one continent to another continent and where as others migrated from one region to another region and expanded their life style along with their migration, among those races of people in the group who even left the African continent itself.

            But on 2006 a famous scientist agrees that it was an advantage of pre-humans to keep their hairs retained on their heads and protect their scalp as they were walking in hectic equatorial intense UV Light. And some others came into an argument stating that, as hair was being retained under heavy UV light and so as the other body parts such as shoulders express hairy because these parts putatively exposed to the same conditions. So they have discovered that the retain of hairs on the head used to protect the head and also the brain seat inside head and this helps humans to become one of the most successful species on this planet. During the time of this gradual process the human skin was transferred to naked skin from furry and apparently their hair structure changes gradually to Afro like or kinky like structure from straight like structure. So in this stage the humans slowly lose their straight body hair and tend to expose their naked skin and their fur directly to the sun, so apparently the kinky of Afro Hair or hair which is tightly coiled may have the capacity to prevent the entry of UV light radiation into the body for skin protection.

           And this theory came to the final conclusion that the females sweat less when compared to males and on the other hand it proves that males have more energy than females. So the armpits of human sweat more than any other animal like horses. Which have sweat glands. When compared to horses with humans the similar distribution extended the increased distribution of sweat glands occurred before occurs through the evolution of new trait. When compared to human’s, horses also sweat and they seems to be bigger in size, more hairier and spend more energy in running when compared to humans, so they may not have any apparent connection with the ability to sweat and the apparent hairlessness of human beings. So when it comes between the differentiations of human beings men develops thicker, coarser, darker and longer terminal hair and on the other hand women do not processes the above characteristics of man and they tends by leaving their vellus hair visible. The idea is mainly about the adult human’s exhibit some kind of juvenile type of features which was not evinced in other apes and this was found a century ago. Particularly in females the evolution that was occurred was preferential selection and it was taken further for neoteny.

           When it comes to the thick and thin body hairs on humans, a role played by a sexual selection possessed and that selection is called as fisherian runaway sexual selection. When compared in humans and taken into consideration of males and females, a testosterone in women was taken into consideration was in smaller role. Sexual dimorphism is the thing which clearly explains the sexual selection theory among men and women. When compared to women, men have more body hair in average. The hair which we find on the male body is called as terminal hairs and it’s especially found on the face, chest, abdomen and back. Whereas females have less number of hairs and this type of hair is called vellus hair which is less visible sometimes not found also. In response to ectoparasites, a final hypothesis has been done and found that the human hair is reduced. Getting rid of or in accordance with the reducing of hair may reduce the risk from fleas, ticks and lice which do harm by biting.  In 2006 they have invented new hunting techniques in East Africa the evolution of stronger and larger body and brain sizes led due to the higher protein.

              By sweat evaporation only one could able to get thick hairs. Even though hair provides a good protection against UV radiation which is harmful and they found that only our head were exposed to the sun and found that hairs are the good reflector of UV radiations and thick hair on head provides the protection against harmful UV radiation but when its compared to our body hairs it is reduced. When it comes under the thermoregulation research of Wheelers on hairs he actually neglects the assumptions. He actually explains that the human body turns warm at night even without possibilities of body hairs. Among mammals, horses retain their body hair when compared to humans even though it has sweating glands like humans where as humans sweat more than horses but they can’t. So it has been taken into an experimental consideration whether there is interfere of any hairs during the time of sweat evaporation. Where as humans sweat more than horses because he is not having fur or lack of  hair all over  the  body like horses. At last wheeler’s thermo regulatory hypothesis study results and stays the most accepted explanation for the human hair. Apart from mammals, the theory did upon aquatic ape yet has to get gang support among scientists.

         So horses and Humans are the two mammals, are capable of sweating because these two mammals has sweat glands which produce sweats. But when compared to horses, they have larger and fully developed fur when compared to humans. For humans the skin hairs lie flat during hotter climate or in any hot conditions, because the erector muscles erect. Whereas in winter season the erector pili muscles works and it makes the hairs to erect. The pili muscles prevent any heat from external source from being get trapped by a layer of still air found between the hair spaces and it eventually increases heat loss by conventional methods. So the reduction of hairs in the body apparently reduces the sweat which comes out of the body. So when coming to hair losses some ideas have been given and advancement in explaining the hairlessness of human beings as when compared to other mammals or species.  It is being discovered by the experts that the humans began to stay cool by sweating more when they started to live on savanna; this study has been done by thermoregulatory hypothesis study during the year 1984 by a famous scientist named Dr. Peter Wheeler

             It is likely said but not clearly estimated the change in their body hair appearance, whether it’s been occurred before the development of sweat glands or after the development of sweat glands. Human have a type of sweat gland all over the body that keeps the body always cool off and that name is eccrine sweat glands. Most mammals apart from humans have Eccrine sweat glands just in their hands and feet where as their rest of the body is covered with another type of gland called apocrine glands, these type of glands are not used to cool their body. So there is a peculiar trend in primates of humans that to have eccrine sweat glands in excess over the surface of their body and it proportionally equal to the degree of what other primates do sweat accordingly in response to heat evolvement. The humans have the specific capacity of sweat glands evolvement where as it could spread the glands from the hairs and feet as because of hairs in the body has been changed. As the change in the hair gland, this could have eventually occurred to facilitate sweating. So taking into consideration of humans with other mammals, horses are capable of sweating.

                  He then prepared for estimation that before how many years that these clean sweeps took place and then estimated approximately it took place 1.2 million years ago, and then he approximately concluded that this apparent bareness in human body has existed at least likely since that time. In case of Balding, the terminal hair switches to vellus hair where as it usually occurs at around 30-40 years of age. In ancient times most of the individuals were not so likely to live till 30 and so it was likely that it was subjected to selection. As we have already discussed that the soft and fine hair like particle present or that can be seen through our naked eye on so many non human mammals is called as fur. Most of the species involved at the climate in Africa or any other places like Africa, to adjust their temperature regulation to the Cold snow, UV and hot sunlight at the equator. They do mostly by panting. For enabling perspire, they have developed sweat glands. They have possessed fur like structure about early 2.5 million years ago. But it is not still very clear about the appearance of body hairs of humans.