Introduction
Placental mammal is another name used to refer to primates. They include humans, apes and monkeys. Their different adaptive strategies have enabled them to survive in different environmental conditions. Availability of various foods in the forest forced them to become omnivorous. There are different factors to consider when learning about evolutionary trends of primates. These factors include diet and dentition, Crania and Limbs. This paper analyzes the evolutionary context of prosimians, anthropoid monkeys and hominoid apes. In addition, it will address the main cause of extinction among Miocene apes.
Prosimians
Prosimians are found in the order Primates together with anthropoids. Research indicates that, these primates evolved earlier than anthropoids. This is the reason why archeologists referred to them as lower primates in the 19th Century. Lorises and Lemurs are outstanding examples of prosimians. They were mainly found in tropical regions like North America. This has changed over time; records indicate that, Old World provides an ideal environment for these species. Lemurs mainly inhabit Madagascar Island. These species had a bushy tail that provided them with stability when moving from one tree to another. There herbivores nature enabled them to consume leaves, fruits and roots available in the jungle. Research has it that these species are more social than lorises (Simons, 2009).
Cheirogaleidae is one among the families of Lemurs. The size of full-grown species can be compared to that of a mouse. Fruits, baby birds and insects, make up the diet of these species. There sharp sense of hearing plays a vital role in hunting at night. Avahis, Sifakas and Indris, are in the Indriidae family. These species are bigger than other species from other families. These species use piercing vocalizations in order to guard their territories. Their long legs help them in moving from one tree to another. It is due to the nature of their legs that these species cannot be able to walk but hop. Daubentoniidae is the last family of lemurs. These species are not common because they reside mostly on trees. Their teeth and hands are unique compared to other primates. Their long incisor teeth and elongated fingers help them to obtain food from tree barks and coconut meat (Simons, 2009).
Anthropoid monkeys
Suborder Anthropoidea consists of one hundred and forty five species. Monkeys make up 90% of these species. Ten percent is mainly humans and apes. These species are more developed, intelligent and larger than Prosimians. The origin of these primates is not clear. There are different individuals who have tried to explain the origin of these primates by providing evolutionary rootstocks, places and time. Some researchers argue that anthropoid monkeys mainly evolved from prosimian primates. It is not easy to understand the evolution of anthropoids without focusing on their origin. Most individuals argue that Africa is the cradle land for these primates. Some archeologists strongly opposed this argument claiming that anthropoids did not have anything to do with Africa. They held that Asia is the cradle land for anthropoids (Trevathan, Kilgore, & Jurmain, 2011).
Catarrhine and Platyrrhine are an example of anthropoids’ infra orders. Platyrrhine has a nose that is flat with a broad septum while Catarrhine’s nose has a narrow septum. Catarrhine’s nose can be compared to that of man. Anthropoid monkeys have mammalian teeth that used for eating different types of foods. They include incisors, canines, premolars and molars. Incisors play a crucial role of nipping food. Canines do tearing and piercing of food. The multiple cusps of molars and premolars enable them to grind food. 2.1.3.2 is the dental formula of primates. Catarrhines have a different dental formula from other primates. Their dental formula is 2.1.2.3 (Trevathan, Kilgore, & Jurmain, 2011).
Old World anthropoid monkeys have the same dental formula like that of Catarrhine. Old World monkeys are bigger than New World monkeys. In addition, they are semi-terrestrial while New World Monkeys are arboreal.Prehensile helps New World monkeys to hold on branches. Ischial callosities enable Old World Monkeys sit and sleep for long periods. In addition, these pads enable them to sit on surfaces like rocks and branches. Some Old World monkey females have swellings on their genitalia (Simons, 2009).These swellings occur due to hormonal changes in their bodies. These changes are essential for ovulation preparation. These swellings also play a crucial role in attracting male species through odors they produce.
Hominoid apes
Research indicates that different geographic and environmental factors played a vital role in the development of hominoid apes. These species evolved from Africa and later moved to Eurasia. Hominoids are evident in different countries like, India, Hungary, Turkey, Pakistan, Western Europe and China. In order to understand these species, archeologists have divided their evolution into different forms. They include African form, European form and Asian forms (Jablonski & German, 2004).
This primate had a larger brain capacity than other primates. Its ability to adapt to changes in the environment enabled it to survive in Eurasia. Some apes specialized in taking fruits and leaves while others specialized in consuming small birds. The bipedal posture of these apes enabled them to climb on trees easily. Another similarity is evident from the nature of his hand. He had hands that could enable him grasp food and tools (Jablonski & German, 2004).
Extinction of most species of Miocene apes
Some people tend to think that evolution for apes has seized while that of humans is in progress. The truth is that, evolution for apes is the same as that of humans. Fossil record indicates that, the evolution for Miocene apes is poor just like that of humans. Eurasian climate was initially ideal for the survival of these primates. The forest temperatures were extremely warm. In addition, adequate rainfall enabled enough supply of fruits and leaves that served as the main source of food for these primates (Trevathan, Kilgore, & Jurmain, 2011).
It is clear that Miocene apes are becoming extinct. Nature has been blamed to the causes of this extinction. Some individuals argue that, the major contributors towards the extinction of Miocene apes are human activities. Climatic change and rainfall reduction have led to fragmentation of forests. Forests are the main source of food for Miocene apes. This means that, lack of forests forces these species to starve to death. Habitat destruction carried out by man causes this extinction. Farmers clear forests in order to attain land they can use for practicing agriculture. Man also clears bushes in order to attain charcoal and wood for cooking. Man has also been accused of capturing these animals as pets (Simons, 2009).
Conclusion
Primates can also be termed as placental mammals. Primates are made of different groups of species. Each group had unique features and behaviors that enabled it to adapt and survive in its environment. These groups include prosimians, anthropoid monkeys and hominoid apes. The evolution of these primates took place differently. The period at which prosimians evolved called Paleocene. Anthropoid monkeys evolved during the Eocene age while hominoids evolved during the epoch age. These primates mainly attained their foods from trees. They fed on insect, birds, insects and roots. Research indicates that human activities have significantly contributed towards the extinction of Miocene apes.
References
Jablonski, N. G., & German, R. Z. (2004). Shaping Primate Evolution: Form, Function, and Behavior. Cambridge University Press: Cambridge. Print.
Simons, E. L. (2009). Primate evolution: an introduction to man’s place in nature. Michigan: University of Michigan. Print.
Trevathan, W., Kilgore, L., & Jurmain, R. (2011). Introduction to Physical Anthropology 2010-2012. New York: Cengage Learning. Print.