Humans as a Diverse Species

Humans as a Diverse Species of Primate

Earlier it has been really hard for humans to acknowledge that we are indeed one among the primate species and that we are distinct from other primate species only in certain ways with regard to the construction of our body. But presently there is no question of any disbelief. (O'Neil 2007, p. 569) it was Linnaeus who was able to distinguish the fundamental morphological resemblances among humans and other non-human primates like apes by clubbing them collectively in the order 'primates', albeit in different genera. For this he did not employ any mid-way group of arrangement between 'genus' and 'order'. (Bruce & Ayayla 1978, p. 264) Within the human populace as also in case of the other primate species, the genetic mix of every populace is impacted by the due process of time to adapting impact of divergent factors. These are natural selection, encouraging adaptation of the populace to the surroundings; alteration, entailing changes to the genetic substance; admixture, resulting in genetic interchange among regional populations, and haphazardly altering rates of genetic features from one generation to the other. (Charles, 1996, p. 570)

Leaving aside certain external disparities, humans are rather similar to certain other primate species such as African apes anatomically as well as genetically, particularly to the chimpanzees and bonobos. The research on finding the complete genome of ordinary chimpanzees was done during 2005. A comparative analysis between this and the work on the human genome concluded in 2001 reveals that humans as well as chimpanzees have 98.77% of identical DNA base pairs. (O'Neil 2007) Further the heart and liver in case of humans and chimpanzees have almost the same numbers of up as well as down-regulated genes. (Caceres; Lachuer, et. al 2003, p. 13031)

Another similarity is that apes as well as other nonhuman primates identify their offspring immediately after they are born and remain closely linked with them during a postpartum period. (Chapman; Thomas; Gillespie 2005 p. 136) a University researcher has discovered in a study which indicates the identical repercussion in case of humans, who akin to other primates, exhibit a really strong impetus to care for their young. Through analyzing various reported instances of primate infants being parted from their mothers and accepted by other females soon following their birth, Maestripieri witnessed proof that primate mothers are also able to identify their offspring during the early stage of their lives and experience a sensitive period of bonding with them. Although olfaction is poorly developed in primates as well as humans in comparison with other mammals, apes and human mothers are perhaps able to identify the odor of their babies following few hours of their birth and understand their visual and also oral features soon thereafter. (Harms 2001, p. 7)

Besides, other primates have several other features which are similar to human characteristics. The organization of the central nervous system of other primates as well as humans is nearly similar, and also with regard to the social activities, emotional requirements as well as intellectual potentials of humans and other non-human primates there are found to be similarities. Non-human primates exhibit the capability to argue, to show companionship and self-sacrifice, to experience fright, and tensions similar to humans. (British Union for the Abolition of Vivisection 2007) the non-human primates like that of the chimpanzees as well as bonbos show signs of emotions and objectivivity by way of body language through facial movements and hand movements, a lot of which are used by humans for nonverbal interaction. They are capable of conversing regarding food, personification, or threats to their brethren through vocal sounds which are understood and action taken similar to that of human primates. (de Waal 1995, p. 84)

In this perspective it must be comprehended that although non-human primates such as chimpanzees are incapable to carry out the cerebral work needed for language expression, their brains have areas which are anatomically similar to that of the perisylavian regions of the humans in both the hemispheres. The report, released during July 23, 2006 in the online publication of Nature Neuroscience, reinforces the hypothesis that a common ancestor to humans as well as current non-human primates might have had the important neural mechanisms on which language was formed. (Bethesda 2006, p. 4) Finally, humans as well as other non-human primates have the similarity with regard to having diseases that are associated with tension compared to others of the animal world. The solution according to Stanford University neuroscientist Robert Sapolsky, is that people, apes as well as moneys are extremely intelligent, social creatures with a great deal of extra time at their disposal. (Why Do Humans and Primates Get More Stress-related Diseases than Other Animals? 2007)

In spite of the similarities between the humans and other nonhuman primates, there also exist differences between them. Among the primates, human society has the maximum levels of diversity. Males bond for joint ventures, while females also unite with each other of their own sex group. Monogamy, polygamy as well as polyandry are extensively witnessed. (de Waal 1995, p. 85) it is the human beings who are adapted biologically for the purpose of culture in the ways in which the other primates are not, which is proven most explicitly by the reality that only exclusively human cultural civilization accrue changes over the due course of time. The important adaptation is that which permits people to have mutual appreciation as deliberate representatives akin to the person himself. This characteristic of social cognition that is species-unique surfaces in human ontogeny at around the first year of the life of the infant, when they start associating with other people in several types of mutual exercises where attention is necessary like following the eyes, social referencing, as well as gestural interaction. The mutual attentional proficiency of young children then produce certain distinctly strong types of cultural learning, permitting language learning, speaking expertise, skill in the use of instruments, and a lot of other conventional exercises. These ingenuous types of cultural learning permit humans to club their cognitive resources both in the existing manner and traditionally in means that are quite different from other primate species. (Tomasello 1999, p. 514)

Although the study of 2001 as mentioned earlier in this paper showing the comparison between the genome of ordinary chimpanzees and humans reveals that 98.77% of the base pairs of DNA of humans as well as chimpanzees are identical, an extra 2.7% variation exist between both the two species in duplicated sections of DNA. Our areas of differences from chimpanzees seem to be generally in the genes which are responsible for speech, hearing, smelling, protein digestion and vulnerability to some diseases. These negligible disparities are supposed to exist considering the fact that our evolutionary paths and that of chimps have been fundamentally different for 6-7 million years. At that time, we were put to fairly separate natural selection demands. Because of these differences, it has resulted in bipedalism in case of the ancestors of humans including a very bigger brain and, eventually speech. (O'Neil 2007)

Another important difference exists between humans as well as other non-human primates which are important to be understood. We are the only primate species wherein elderly females attain menopause and turn infertile, often several years prior to death due to old age. On the contrary, female gorillas, chimpanzees as well as other non-human primates generally are able to retain the potential of becoming pregnant and delivering babies even in their old ages. After menopause they live a comparatively less time in case they pass through it. One justification for this difference in case of humans is that the living years after menopause has confirmed to possess natural selection value in case of human primates. After having brought up their own offspring, women in the post-menopausal stage across the world often look after their grandchildren when their daughters are busy in their jobs. It is reasoned that this makes the chances brighter that the grandchildren will live life till adulthood as they get this added experience and tender care. (O'Neil 2007)

Another difference is that the brain of modern humans is thrice bigger in size compared to that of the great apes. More significantly, the proportion of human brain to body is considerably bigger, and the cerebral cortex is very bigger. The human brain exhibits a characteristic mode of gene expression corresponding to other non-human primates, having elevated levels of expression in case of several genes of a broad diversity of functional level of classes. The elevated expression of these genes could cater to the foundation of broad amendments of cerebral physiology as well as function in case of humans and recommends that the human brain features increased intensities of neuronal activity. (Caceres; Lachuer; et. al 2003, p. 13033)

Latest researches have recommended that the larger human brain might be because of the evolutionary alterations in the HAR1 gene area that is responsible for the generation of brain tissue within the 7th and 19th week following conception. It is not startling that some remarkable variation exists between the great apes as well as humans with regard to mental capabilities. Humans possess a lot higher intricate types of verbal communications compared to any other primates. Humans are the sole animal to make and apply symbols as a way to communicate with each other. Humans also have diverse as well as complex forms of social organizations compared to that of the other nonhuman primates. The most unique characteristic of humans lies in human mental capability to build novel ideas as well as intricate technologies. This has been considered to be important in the fight for endurance. (O'Neil 2007)

Further, the relatively negligible structural variations among humans and apes are generally an outcome of regular bipedalism observed in human beings. Quite a number of alterations in human bodies were linked to the growth of this type of locomotion. As opposed to apes, the arms of humans are comparatively small and not so strong in contrast to the legs of humans. The human feet have lost the capability to successfully hold and maneuver things as the big toe went up in the same line with the others. The feet in case of humans have also grown in length and has become like an arch, rendering them to better support their body. The human pelvis as also the vertebral column has also undergone changes to lend an upright posture and facilitates bipedal locomotion. Nature possibly chose for longer legs in case of humans as it gives greater efficiency for walking and particularly running using the two feet. (O'Neil 2007)

More remarkable differences do exist between humans as well as other non-human primates. To take an example, research into HIV and AIDS has revealed that almost every other non-human primate does not get infected with the HIV virus. Chimpanzees exclusively are infected with HIV although they do not at all develop AIDS. Likewise, research into Alzheimer's syndrome has been unsuccessful to locate an appropriate non-human primate model on which to find out the progress of the ailment. The basic defect that is central to the research of human diseases with regard to primates remains that they just do not have identical diseases which the humans have. (British Union for the Abolition of Vivisection 2007)

Now we shall understand as to how human population differs from one another. Every human existing in this planet relates to a single species Homo sapiens, and has a universal ancestry. Even though divergence in opinion exists with regard to the manner in which various human categories deviated or integrated to mould new races originating from a universal familial category, all populations living in each geographic regions of the earth have originated from that ancestral category over identical period of time. For several centuries, researchers have wanted to fathom patterns in nature by categorizing living beings. The sole alive species in the human genre, Homo sapiens, has come to be regarded as an extremely widespread universal range of populace. Biological variations among humans show hereditary factors as well as the impact of natural and also social background. In majority of the instances, the variations are because of the interface of the two. (Charles 1996, p. 570)

Regional, climatic as well as historical causes have become responsible for the blueprint of human genetic differences observed in the world currently. For instance, population processes linked with immigration, intervals of geographic seclusion, compulsive endogamy meted out by the society, and natural selection have impacted allele rates in some of the populace. (Berg; Bonham; et. al 2005, p. 524) Further, majority of the biological differences within the human population entails unassuming extent of differences in the rate of mutual traits. The extent to which the surroundings or heredity impact any specific attribute differs a lot. Marked physical variations exist among the populations inhabiting diverse geographic regions of the world. Several of these variations are vehemently present at birth while others like the size of the body and its shape are fervently impacted by diet, lifestyle and other features of the environment. (Charles 1996, p. 570)

The color of the skin is among the most noticeable means in which humans differ and has been extensively utilized to describe human ethnicity. Roughly 10% of the difference in the color of the skin happens within groups, and ~90% happens between groups. The amount of melanin is responsible for the maximum portion of the difference in the visual look of human skin. Difference in melanin pigmentation of the skin in case of humans has been characterized to several causes, with majority of researchers acknowledging that the observed differences show biological adaptations to several facets of the surroundings. The skins having high melanin content belonging to native people of humid regions has been stated to be offering higher barrier against the harmful consequences to UV radiations, like sunburn, skin cancer as well as nutrient photolysis. The reason for the people inhabiting the Arctic areas having lightly pigmented skins have been attributed to the lower UV radiation regimes of those areas and the significance of maintaining UV stimulated biosynthesis with regard to vitamin D3 present in the skin. Added adaptationist theories have laid importance on the importance of skin pigmentation in controlling reaction to frostbite, in prevention to disease, heat regulation, or a blend of these. (Jablonski & Chaplin 2000, p. 61)