Facial Diversity in Primates - Research Paper Example

What drives facial diversity in primates? Introduction Primates are one of the interesting mammals that an individual can keep staring for a long time without getting bored. Various significant features make primates’ faces interesting. One of these features includes the expressive eyes. Other features include the tomato-red skin and the long fur. Another significant feature common in primates is the snout-like nose. Other issues may inspire someone in conducting the research on facial diversity of primates. Some of these issues include the extraordinary diversity of shapes, colors and patterns. All these issues lead to the question of what drives to the facial diversity on primates. This paper will provide detailed information on various factors that drive facial diversity in primates. In order to get the required materials, the paper will include data from primary or review literatures. Factors that contribute to the facial diversity of primates Social Behaviors Social behavior tends be one of the main contributing factors that lead to facial diversity of primates. It is evident that compared to all other mammals that exist on earth, primates are the most social animals. This is the reason behind the fact of why they live in groups. The social behaviors of primates have evolved through the process of natural selection. The behaviors are significant contributing factors to the facial diversity of the mammals. Some of the common features depicted in the primates’ social lives include the fact they are always in groups (Chandrasekaran, 2011). The other social feature of these mammals is that their groups tend to be stable. The groups are always permanent meaning that they stay for a long time without breaking up. The other social feature is that the groups contain adults and young ones of both sexes. Another significant social feature is that primates have a complex social behavior. This translates to the fact that primates’ social behavior tends to have various activities that make the mammals active in most of their times (Chandrasekaran, 2011). The fact behind the reason that makes social behavior influence facial diversity among primates is that they tend to demonstrate various facial expressions while reacting to different social-ecological challenges. The flexibility that emerges during these periods of which the primates try to cope with the social-ecological challenges plays a significant role in determining their facial diversity (“Social Needs Help Sculpt Primate Faces”, 2011). This means that challenges, such as harsh environmental conditions, contribute in influencing the facial diversity of primates. Moreover, the behavioral drive model indicates that social behaviors tend to play a significant role in driving the in increasing complex of facial color (Harding, 2010). For example, some of the primate species that live in smaller groups tend to have various complex patterns of facial color. Primates that live in regions where there is a higher number of congener species tend to exhibit the same characteristics of having complex facial color. Another significant example that tends to support the fact that social behaviors influence facial diversity of primates is the fact that species that those live closer to the equator tend to have darker crowns (Harding, 2010). Furthermore, the species living near the equator also tend to have dark eye masks. However, those species that live in the far western of the tropics tend to have darker noses. The species also seems to have dark mouths while their masks tend to be lighter compared with those that live near the equator (Harding, 2010). Another significant issue to consider is that various patterns in the primates’ faces tend to contribute to facial diversity. Some of these factors include facial patterns such as skin and hair color. These features develop in order to help the primates communicate and recognize each other. An example that supports this fact indicates most of the primates that tend to live in smaller groups have different significant features compared to those that live in larger groups. This means that the species that live in smaller groups have facial figures that seem to be more complex compared to those that live in large groups. The following figure shows how geographical regions contribute to various social behaviors influencing facial diversity of primates. Genetic based methods also play a crucial role in enhancing social behaviors that contribute to facial diversity of primates. An example of genetic related that contribute to facial diversity of primates is metachromic sequence. The metachronic sequence of hair coloration change presents reliable evidence that facial coloration occurs in primates (Santana, Alfaro & Michael, 2012). Retrieved from: Santana, S. E, Alfaro, L. J. & Michael, E.A. Adaptive Evolution of facials color patterns in Neotropical primates. Proceedings of the Royal Society. (279), 2204-2211. Ecological Factors Ecological factors are also contributing factors that play a crucial role in driving the facial diversity of primates. Some of the factors related to ecology that influences facial diversity in primates include change in ecology. For example, change in the environmental conditions leads primates to adjusting to another living condition. The new area of living may force the primates to adapt in a simple or in a complicated way. In areas where the primates adapt in a hard way, they tend to develop complex facial features. However, in areas where the primates adapt in a simple way they tend to develop facial features that are not complex. Another ecological factor that contributes to facial diversity in primates is their competition over various resources. Some of the resources that the primates tend to compete include shelter. The strong ones manage to secure shelters that are more firm and stable compared to the weak ones. These states in which the weak ones manage to adapt to the poor shelters contribute them in driving to facial diversity. Therefore, it is evident that completion within the ecosystem that the primates live on contributes to their change in facial expression and diversity. Demographic Factors Various demographic factors drive to facial diversity in primates. Some of the demographic factors include food competition. Primates tend to demonstrate various behaviors while they compete for foods of which are not in others. For example, the female primates do not have more power like the male ones when competing for food (Watson & Caldwell, 2009). This translates to the fact that they exhibit various facial movements that contribute to influencing their diversity. Another issue related to food completion is the fact that some of the primates that feed on various products different from others tend to influence facial diversity that is not in other species of their family. For example, some of the primates that feed on insects tend to have their eyes moving closer to the front part of the face. Another significant issue to note related to demographic factors is that primates tend to exhibit different facial diversities depending on the area that they are living in. For example, most of the primates live in humid areas seem to have many hairs upon their skin. Moreover, most of the primates that live in dense forests also tend to have many hairs upon their skin. This particular group of primates tends to have long hair. However, as groups of primates’ gets near the equator, their hair gets shorter. This is because of the temperature regulations that take place in their bodies (Watson & Caldwell, 2009). Behavioral factors Various behavioral factors contribute in influencing the facial diversity of primates. The behavioral factors also play a crucial role in determining how the primates perceive the worlds. These factors also tend to determine how primates communicate with each other while enacting various activities in their environment. Some of the behavioral factors that primates exhibit and which influence facial diversity include vision (Haslam, 2009). Vision is one of the most significant factors considered dominant in matters related to sensory modality in most of the primates. Some of the primates, such as monkeys and the apes, have a high visual acuity. This means that they manage to see objects that are in a long distance. Moreover, these primates can also differentiate between objects that are in short and in long distances (Haslam, 2009). An example that demonstrates how vision influences facial diversity in primates is visual stimulation. The point of view of various primates contributes much to their facial diversity. When primates receive bright or more light they tend to experience various effects on their facial diversity. A significant example that fully demonstrates this fact is in situations where primates are housed in cages. In such case, primates tend to have various different facial features compared to those that are not housed. This is because the housed ones keep on changing and adapting to new visual stimulation depending on how much time they are able to access light (Haslam, 2009). Another significant issue demonstrated in areas where primates are house in cages is that mirrors also tend to affect their visual stimulation. This means that most of the primates in the housed cages may influence their facial diversity through looking on mirrors where they expand their environment. The following diagrams show an image of how caged primates tend to influence their visual diversity through visual stimulation and seeing wider images on a mirror. Retrieved from: http://www.nc3rs.org.uk/news.asp?id=187 Genetic based methods also support the fact that behavioral factors influence facial diversity in primates. An example of such a genetic based method is the behavioral drive hypothesis (Hopkins et al., 2007). On their research, Santana, Alfaro & Michael (2012) illustrated that various points of mutations tends to lead in the distribution of eumelanin and pheomalanin in primates. Moreover, they also indicated that these genetic underlying changes tend to cause dramatic difference in hair coloration (Santana, Alfaro & Michael, 2012). Evolution Evolution is another factor that plays crucial role in influencing the facial diversity of primates. Evolution tends to give the answer of why most of the primates seem to have dramatic changes on their faces compared to others. Most of the scientists believe that life is a continuous process where primates develop to features that are more complex even though it takes much time (Hagelin, 2004). Most of the primates that evolved during the first stages of evolution tend to have simple facial features compared to the ones that evolved later. The facial features are different from hair and the skin. Some of the factors that contributed to the primates which evolved during the first stages of evolution to have facial diversity that are more complex include being in low numbers (Hagelin, 2004). This translates to the fact that most of the primates that live in smaller groups tend to have facial diversity that are more complex. However, those primates that live in large groups tend to have facial diversity that is more simple and plain. For example, humans have faces that are prettier and bare in terms of the amount of hair. Some of the factors that tend to contribute in most of the primates living in smaller groups to have complex facial diversity include the fact that they do not communicate much using their facial expressions. However, most of the primates that have plain faces tend to communicate much using facial expressions. This means that facial expressions tend to be of greater importance and used in different ways by primates within large groups. Moreover, this issue is supported by the fact that humans tend to have plain faces because they are highly social. This means that the facial expressions contribute to the situation where humans find their faces plain (Hagelin, 2004). Another significant factor to note is that in areas where the primates tend to live as a family or they are more related, they tend to have complex faces. However, in areas where the primates tend to live in an environment where they are not closely related to one another, they seem to have simple and plain faces. In this case, the size of the group does not really matter (Hagelin, 2004). Some of the genetic methods that support the concept of facial diversity in primates that relate with evolution include phylogenetic analysis. While using phylogenetic analysis method, Santana, Alfaro & Michael (2012) indicate that they managed to discover there is an evolutionary relationship social and facial color complexity across Neotropical primates. Santana, Alfaro & Michael (2012) also indicate that the evolution complex phenotypes occurs mostly because of genetic factors acting on various different part of primates’ bodies, especially the face. Krause (2009) indicates that through the phylogenetic analysis, scientists managed to discover that Microcephalin genes and ASPM have a strong positive selection on facial diversity of primates. Conclusion The above information indicates that various significant factors drive facial diversity in primates. Some of the addressed factors include social behaviors. These factors translate to the fact that primates influence their facial diversity according to how they conduct socially. The other addressed factor is ecological factor. Moreover, other factors that contribute to the influence on primates’ facial diversity include demographic, behavioral and evolution factors. All the above addressed factors are the main contributors to facial diversity in primates. Some of the generic based methods that contribute to facial diversity in primates include metachromic sequence, behavioral drive hypothesis and phylogenetic analysis. References Chandrasekaran, C., Lemus, L., Trubanova, A., Gondan, M. & Ghazanfar, A. A. (2011). Monkeys and Humans Share a Common Computation for Face/Voice Integration. Plos Computational Biology, 7(9), 1-20. Hagelin, J. J. (2004). Use of live nonhuman primates in research in Asia. Journal Of Postgraduate Medicine, 50(4), 253-256. Harding, L. E. (2010). Trachypithecus cristatus (Primates: Cercopithecidae). Mammalian Species, (862/863), 149-165. Haslam, M. (2009). Primate archaeology. Nature, 460(7253), 339. Hopkins, W., Taglialatela, J., Dunham, L. & Pierre, P. (2007). Behavioral and neuroanatomical correlates of white matter asymmetries in chimpanzees (Pan troglodytes). The European Journal Of Neuroscience, 25(8), 2565-2570. Krause, K. (2009). Change we can believe in: "race" and continuing selection in the human genome. Humanist, 69(1), 20. Santana, S. E, Alfaro, L. J. & Michael, E.A. Adaptive Evolution of facials color patterns in Neotropical primates. Proceedings of the Royal Society. (279), 2204-2211. Social Needs Help Sculpt Primate Faces. (2012). American Scientist, 100(3), 248. Watson, C. I. & Caldwell, C. A. (2009). Understanding Behavioral Traditions in Primates: Are Current Experimental Approaches Too Focused on Food? International Journal Of Primatology, 30(1), 143-167. Read More