The Contribution of Both Social and Ecological Factors - Research Paper Example

What Drives Facial Diversity in Primates? s What Drives Facial Diversity in Primates? Introduction Evolutionary biology is based on the interaction between phenotype and genotype. A good number of biologists have agreed that genotype changes can be altered by phenotypic changes. Phenotypic changes, as a result, influence organisms’ survival and reproduction. However, the relationship between genotype and phenotype changes is a very recent discovery (Jessica, Sharlene and Michael, 2012). Many qualitative and quantitative researches are still underway to identify the relationship. For a long time, the basis for facial diversity among primates has been an issue of concern among naturalists. Many researchers have resolved that social factors have the prevalent contribution in the emergence of primate facial diversity. Facial characteristics of primates are complex structures that are designed to fulfill several purposes. Primate face is made up of various phenotypes as it integrates various parts such as eyes, ears, nose, hair and patches of skin. All these organs differ in their traits and functions. These parts have different location, origin, colour, size and shape (Cartmill and Smith, 2009). The nature and shape of the elements in a primate face is to a great extent determined by social factors. In many social animals, facial traits offer an adequate source of information that is significant in social interaction. The face is used to express signs regarding primate behaviours, condition and identity. Given the role of face in social interaction, it is sensible to assume that social factors have a crucial contribution in enhancing facial diversity in primates. Facial diversity in primates is explained by the differences in characteristics, shape, colour and size expressed by different primate in the world. According to biologists, facial diversity among primates is highly contributed to by emerging social factors (Bradley & Lawler, 2011). The essay below will present some of the important social factors in driving primate facial diversity. In this essay, the author will provide evidence on the contribution of both social and ecological factors in directing diversity in primates. Pattern of Social Group Primate Species Female and her offspring Some human being and nocturnal Monogamous family Some human and small Asian ape Polyandrous family New world monkey Several female and one male Howler monkey some human geladas and langurs Multimale-Multifemale Columbus, savannas baboons and some new world monkey Fission-fusion society Chimpanzee (Dufour, Pascalis and Petit, 2006) The table above illustrates the nature of social interaction among different primates in the world. It shows the social status of different players in their social settings. From the table, it is clear that the social responsibility among male and female primates varies from one primate to another. According to the table, facial diversity is highly influenced by social setting which primates engage in. Social Behaviours Many primates spend most of their lives in specific social groups. Primate social behaviours are significantly influenced by primate social groups. The manner in which primates act, communicate, interact and socialize is to a large extent determined by social groups. Different social groups conduct their activities in different ways. This elucidates the emergence of facial diversity among different primates. The features of the face of capuchin monkey are different from the features of chimpanzee. The differences are due to the differences in their social groups. Therefore, social traits have proved to be the main driving factors of the high morphological diversity of primate faces. On the other hand, behavioral factors entail the range of behaviours exercised by primates in their social, political and economic interaction. Behavioural factors are influenced by primates’ attitudes, culture, values, authority, genetics, rapport and ethics. There are behaviours that are common among primates while others vary depending on the prevailing social setup. Behavioural factors determine the visual cue used by primates in their interactions. The table below shows phenotype variations on social behaviour among primates (Bradley and Lawler, 2011) Phenotypic Variation: Social Behavior Example Candidate Genes Example References Gregariousness, social bonding AVPR1A 80, 81, 123 Social anxiety SLC6A4 150, 133 Aggression MAOA 134 Risk aversion, novelty seeking DRD4 145, 73 Behaviors in a group are also determined by female and male philopatric in a group or a family. Female philopatric is a social system whereby female remain in the social group or family in which they were born. In this kind of social situation, male leaves the group for sexual maturity. Due to the inefficiency of male in their families and social groups, females attract males from unrelated group. Mating between social group female with unrelated male brings about a new species in the group. The new species in the group develop unique facial characteristics such as colour, shape and size. However, the new traits must rhyme with the social behaviors of their mothers’ social group. In most cases, after mating, unrelated males return back to their original social groups, thus leaving females with the responsibility of socializing with the newborn (Darwin, 2002). On the other hand, male philopatric is the situation in which males remain in the group or family in which they were born. Female in this case leaves the group for sexual maturity. As a result of this, female attracts unrelated male in the group for sexual maturity. Intergroup mating leads to the emergence of new species. However, in most cases the newborn do not mature in the male social group or family. The newborn develop with different biological traits and makeup. Despite the differences in biological and genetic makeup, the social behaviours in the new groups force the new species to develop facial characters that will make them fit in the new group. Some of biological traits, such as colour, may to some extent not change completely but there are some behavioral traits that will change. The table below shows phenotype variations on mating behaviour among primates (Bradley and Lawler, 2011) Phenotypic Variation: Mating Example Candidate Genes Example References Mate bonding AVPR1A 80 Sexual signaling Hair and Skin Pigmentation MC1R, SLC24A5, ASIP 130, 140, 142 Iris Color OCA2 30, 31, 32 Hair Growth and Texture EDAR 127 Body Odor ABCC11 61 Sperm Competition TGM4, SEMG 124, 126 Promiscuity and STD Immunity CD45 152 The combination of new biological traits developed due to intergroup sexual and social behavior, therefore, lead to the emergence of facial diversity in a group. In this case, therefore, female philopatric brings facial diversity in their original families while male philipatric spreads facial diversity in other families or social groups. Male and female philopatric may also lead to the emergence of sexual dichromatic. Sexual dichromatic is the situation in which female and male in the same species have different facial colours and facial patterns. The sexual dimorphism also alters the color pattern among different primates. The color pattern of mandrill male monkey is a clear example of sexual dimorphism. The colorful face of alpha male is also another example of sex dimorphism (Dufour, Pascalis and Petit, 2006). The table below shows the rate of philopatric sex in different social groups. Species Number of male Number of female Monkey 2 1 Wood rats 8 2 Booboo 12 4 Chimpanzee budongo 15 6 Chimpanzee taii 12 4 Red grouse 54 10 Bell miner bird 25 15 (Dufour, Pascalis and Petit, 2006). The table expounds the nature of philopatric sex among different primates. From the table, it is clear that males are dominant in philopatric sex. As a result of this, male social behaviors are the greatest contributor to facial diversity. Solitary is another social factor that contributes to primate facial diversity. Solitary is the situation where a primate opts to scavenge separately. Those primates that engage in a solitary form of living are referred to as solitary primates. Solitary is more perceptible among male primates. In this situation, males do not associate with other males in their social life. Male offspring are, therefore, excluded from a group or a family after maturity. Solitary primates are common among prosimian species. On the other hand, social primates involve primates that interact with each other in their social life. In most cases, social primates have social groups in which they engage. The behavior of a primate in such cases is influenced and directed by social structures. There is limited facial diversity in the species which capitalizes on solitary form of life compared to the social primate. This is because facial traits of social primates are in most cases influenced by their group’s social institutions and structure. Additionally, primate which lives in small groups tend to have complicated facial pattern compared to organisms living in large groups. This is due to the fact that primate in small groups tend to have cross interaction among them compared to primates who interact in big groups (Schmidt and Cohn 2001). Ecological Behavior Ecological behavior involves the primate reaction to the environment. It includes the manner in which primates adapt to a specific environment (Waal 2008). In most cases, a primate develops traits that enable them to adapt to the ecology. The new traits developed by primates are, however, influenced by social factors. The new adoptive traits facilitate an organism with selective advantage in the environment. Different organisms have unique method of surviving in different ecological situation. There is a significant facial difference between primates that live in tropical environment and those that live in cold places. The facial diversity is to some extent influenced by ecological factors. There are exceptionally distinct differences between the facial nature of the primates living in cold regions and those living in dry areas. Primates in tropical environmental conditions have bright skin colour (Hoekstra, 2006). The colour of their fur is also bright. The brightness of the skin colour enables the primates to reflect excess heat in tropical areas. Additionally, primates in tropical areas have few furs in their skin to reduce the amount of heat stored in the skin. Their skin is also tough to facilitate their survival in harsh dry environment. The tropical primates have a thin skin to aid fast elimination of the heat in their body. On the other hand, primates in cold environment have hairy skin. The hairy skin enables them to accumulate sufficient amount of heat in their body. The colour of their skin and fur is also dull to enhance storage of heat in their body. Finally, primates in cold environment have thin skin which permits adequate preservation and storage of metabolic heat in the body. In general, the two cases explain the contribution of ecological factors to primate facial diversity. Despite of the contribution of ecological behavior, the facial diversity among the two types of primates is to a great extent influenced by social structures in their habitat. The manner in which primates interact with the environment determines the modification in facial traits among the primates (Setchell, Jean and Knapp, 2006). Behavioural Factors Visual cues influence the meaning of the spoken words among primates. In some cases, visual cues influence primate brain reaction. This can be explained by the fact that new world primates have complicated brain capacity compared to old world primates. This is due to the advancement in social interaction among new world primates. Modern social developments have a significant contribution to brain development of new world primates. On the other hand, different primates use visual cues differently. The use of visual cue in most cases is socially constructed. Some visual cues used by one society can be irritating when used in another society. For example winking in some developed countries like United Kingdom is a sign of lack of respect while the same portrays affection in South Africa. The difference in the use of visual cue in different social settings therefore leads to facial diversity. The shape and nature of some facial features are shaped by the way in which visual cues are employed in different societies. Some characters commonly influenced by visual cues include the nature of the skin as well as the size of such facial features as nose. Evolutionary Factors In biology, evolution factors entail all the aspects that interfere with genetic pool in an organism. It includes all the factors that lead to the changes in the population genetic pool. These changes are brought about by new combination of alleles in the organism chromosome (Schmalhausen, 1999). The chromosome changes are highly influenced by change in evolution. Most biologists purport that facial diversity is to some extent determined by evolutionary factors. Changes in the chromosomes traits are adversely influenced by the combination of some social factors and some evolutional factors. This can be illustrated by the straightforward differences between old world primates and new world primates (McNally, 2004). To affirm the difference between old world primates and new world primates, we will compare the differences in facial traits among the new world monkey and old world monkey. To start with, a new world monkey has a flat nose while an old world monkey has down facing nose. The difference in the nature of the nose is brought about by some changes in chromosomes. The nostrils of an old world monkey are open and far apart while the nostrils of a new world monkey are open forward and closer together. The new world monkeys have three premolars. They also have relatively large molars. On the other hand, the old world monkeys have two premolars. The two premolars are specifically used to sharpen upper canine. The molar cusps of the old world monkey are sharply connected. The tympanic membrane of the new world monkey is well connected by bony ring with the external ear while the tympanic membrane of the old world monkey is connected to external ear through bony tube. The new world monkeys have prehensile tails whereas the old monkeys’ tails lack prehensile features. Conclusion In conclusion, it is relatively impractical to talk about primate facial diversity without mentioning some crucial social factors which drive facial diversity among primates. Since a very long time ago, social factors have demonstrated their absolute role in defining and directing facial diversity among primitives. Primates alter their facial characteristics to fit in certain social settings. Face has a significant role in facilitating social interaction. Primate relies mostly on their facial appearance to express their desires and will. Although other factors such as ecological, biological and evolutionary have a role in facial diversity, social factors have the most apparent role in driving facial diversity. Primates adapt differently to social factors in their areas of jurisdiction. More research is, however, needed to understand the importance of other factors in driving facial diversity among primates. On the other hand, there is also a need for more research to compare the existing relationship between all factors involved in facial diversity. References Bradley, B. J. & Lawler, R. R. (2011). 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