Evolution of Locomotion and Body Configuration
Introduction
The evolutionary changes came about because of the need to adapt to the new environments. Before evolving to the grounds, primates are believed to have stayed on trees in the tropical forests. Through these periods, there have been presentations of many characteristics. For the sake of survival, the primates have had to adjust to the climate and geological changes that the earth encounter. The changes still occur in the present day. As a result of the transformation in the environment, primates experienced changes in their bodies, and they developed better movement ways. Evolution is essential in helping animals to utilize new resources in the ever-changing environment. This paper will focus on the development of these adaptive features in the body and movement of the primates. Improvement in the body structure is essential in enabling the primates to survive. Survival depends on their ability to withstand hostility in the environment.
Evolution
There is a variation in the behavioural and physical characteristics of the primates, which allows for evolution. Evolution in the body configuration rises the chances of survival. Primates that evolve without experiencing changes in their structure do not survive for long. The animals face competition in the utilization of resources which are always scarce. Among the most primitive animals are the Lemurs, Galagos and lorises. They belong to the grade one category. Their closeness to the maternal characteristics contributes to them being considered primitive. They rely on olfaction to enhance their smell. They have a dental comb which developed from the projection of canines and incisors while feeding (Diogo &Wood, 2016). They are said to have evolved for an extended period in almost 65 million years. They are found in Madagascar and are composed of different species. They face minimal competition from apes and monkeys hence the difference in their ecological niches. There is also a variation in their sizes with the smallest one being around five inches. The indri is around three feet. Their small size is an adaptation as the Island from which it evolved does not have much space. Their locomotion is also diverse as some are terrestrial while others are arboreal. Among the arboreal species, most of them are quadrupeds while others, for instance, sifakas and indris, are leapers and upright clingers.
In the woodlands of Sri Lanka and India, the Lorises are found. They are also found in the tropical forests and some parts of Africa and Southeast Asia. They are said to resemble the Lemurs, but their survival in the mainland is an adaptation to nocturnal movement. Lorises are not only very slow but also careful; hence they are easily not found by their predators. The length of their hindlimbs and forelimbs are the same. Their tails are not long, and they come in different colours (Groves,2018). When climbing trees, they use quadrupedalism as they are arboreal. Their suspension by the hindlimbs and feeding are enabled by their joints which are flexible and hand respectively. Lorises have a variation in their sizes as well, which is dependent on age and the species. The adults weigh around five pounds and are fifteen inches in size. It is not easy to take away lorises from branches because they grip powerfully. They share the same characteristics as Galagos in gripping and mounting. Their evolution happened in Sub-Saharan Africa, and they are sometimes referred to as bush baby because of their yells and how they appear. The smallest in size is equivalent to a mouse while the large ones have the size of a cat. Galagos are quick climbers with big eyes that enable them to see well at night. They have excellent hearing abilities and long tails for balancing. Besides, they are known to have strong hindlimbs which help them in gripping. They also possess nails except for the grooming claw. Their legs are longer than the arms and are strong enough to support in jumping. The legs store enough energy to enable them to jump up to about seven feet.
Evolution of the second Grade happened in around 53 million years in a place known as Eocene. These tarsiers have five species that live in Southeast Asia (Rylands &Mittermeier, 2014). They stay at the islands in the tropical forests. There is a close resemblance of some traits with the lorises and lemurs. Tarsiers, however, possess some unique characteristics which that the other primates do not have. They are tiny creatures with eyes as big as their brains. They can be carnivorous sometimes, but they are mostly insectivores. They chase birds while moving and catch insects in their jumping activities. Their feet and hands are large, which help them in clinging. When not clinging on branches, they use their legs to hop. Their bodies are about 4 to 6 inches in size. They have long fingers with most of them possessing nails. They also have grooming claws, and their third finger is much elongated than the rest. Their bodies are hairy, and their hands are also padded, helping them to move vertically on surfaces. Their tails are about eight inches long and with few hairs towards the tip. It is used in balancing while their feet and hands are used to hang on branches. They are also known to jump and cling vertically, which finds their prey by surprise. Besides, they are good leapers which are enabled by their very long hindlimbs. They use this trait when clinging on trunks and branches. Their fused leg bones also allow effective leaping.
Grade III entails the monkeys whose evolution took place in the past 35 million years (Larson,2018). They also have unique characteristics which are different from those of the prosimian group. There are the Old and the New World group of monkeys. Their bodies are more substantial, and they are divided based on their differences in characteristics. The New World ones have broad flat noses, and their nostrils protrude outward. The nostrils of the Old-World ones face downward, and their noses are narrow. They are more related to hominoids. The New World has around seventy species and is mostly found in Southern Mexico, Central and South America. They live on trees, and their sizes range from five to 7 inches. Some are quadrupedal while others such as the spider monkeys are semi brachiators because they involve their arms in swinging. Some lack claws, for instance, the tamarins and marmosets and instead have nails which use while climbing. It is worth noting that their forearms are also short. Monkeys in the Old-World group are found in sub-Saharan Africa and some parts of Northern Japan. Their species include colobus, mandrills, langur and baboons. Their sizes range from thirteen to twenty-eight inches. The largest is mandrill while the smallest is talapoin which weighs around three pounds.
They live quadrupedal and arboreal lives, but there is a variation in their locomotion. Some species, however, have long tails like the colobus species. The fourth Grade comprises of men and apes. They are hominoids and began in Miocene, 25 million years ago. The species in this group include humans, gorillas, siamangs, bonobos and chimpanzees. Their bodies are large, stable, and they lack tails. Some are found in Southeast Asia while some species like orangutan are found in Sumatra. Gibbons have long arms and bodies which enable them to jump up to 50 feet, leap and walk uprightly. They have fur, and their feet and face are marked. Chimpanzees are close to humans in their structure and appearance. They can walk bipedally or quadrupedally depending on the distance. Humans have longer arms compared to other primates. They have fingers and thumbs, which they use in grasping. In the past, their bodies were covered with hair which they have now lost. Their brains are well developed to help them in communication and reasoning. In the current times, humans can learn, write and create structures.
Conclusion
It is important to understand evolution and to know how humans evolved. The development has pointed out the link we have with the primates. Chimpanzees, for instance, appear to live in societies with hierarchy. Some primates have similar behaviours to those of human beings. The knowledge is also crucial in understanding other species. For the sake of survival, these primates developed some unique positions for movement and their body structure.
References
Groves, C. (2018). Primate taxonomy. The International Encyclopedia of Biological Anthropology, 1-6.
Rylands, A. B., & Mittermeier, R. A. (2014). Primate taxonomy: species and conservation. Evolutionary Anthropology: Issues, News, and Reviews, 23(1), 8-10.
Diogo, R., & Wood, B. (2016). Origin, development and evolution of primate muscles, with notes on human anatomical variations and anomalies. Developmental approaches to human evolution, 167-204.
Larson, S. G. (2018). Nonhuman primate locomotion. American journal of physical anthropology, 165(4), 705-725.