Fossils records
Fossils records have played a significant role in anthropology because anthropologists can now summarize the life of prehistoric primates on earth. Anthropologists care on the study of the dead because it will allow them to obtain information about the remains of once-existing creatures. Fossils provided a picture of primate’s evolution, and before the first primates died, they were believed to experience a “series of adaptive radiations leading to the diversification of the earliest lemurs, monkeys, and apes” (Shook, et al. 1). Before the existence of modern primates, the earliest archaic primates were known as Purgatorius i who were forced to extinction due to the struggle for new food resources. Another factor that had forced the earliest primate euprimates into extinction was climate change. Some parts of the world had become “increasingly dry, cold, and seasonal and as tropical rainforests gave way to deciduous forests, woodlands, and eventually grasslands” (Shook, et al. 1).
The diverse group of primates that became rare are species of Lemurs, lorises, and tarsier as more anthropoid competitors and predators increased. Anthropologists were eager to explore more about evolution, but the big question was, how did they differentiate primates with other mammals? By observing skeleton and physical traits of a mammal allowed Anthropologists to diagnose a primate. They looked at the traits such as “tooth types, nails, placentation, clavicles, posterior lobe of the brain, orbits encircled by bone, calcarine fissure of the brain, opposable thumb and or big toe, nail on the big toe, well-developed cecum, pendulous penis, testes within a scrotum, and two nipples in the pectoral region” (Shook, et al. 2). Despite Anthropologists proving these traits, many primatologists have argued that these traits are neither clear nor true of all primates, and thus they vary from one primate to another.
Anthropologists did not depend much on the traits I have mentioned above, so they went ahead and come up with hypotheses that explained that showed how primates are unique from other mammals. Arboreal hypothesis argued that primates could move, grasp and grip on branches of trees because of various sizes and our flexible joints. Visual predation hypothesis argued that primates have acute vision that helps in detecting insect prey. Primates have claws used to catch and kill insect for food. The “forward-facing eyes that enable visual field overlap” (Shook, et al. 4). Angiosperm-primate coevolution hypothesis is the third hypothesis that argued about the adaptation of primates to “moving around in the smallest, terminal branches of trees, insects are not necessarily easier to find there” (Shook, et al. 4).
The two groups which were first accepted as primates were adapoids and the omomyoids. These groups become quite distinct over evolutionary time but late on at the start of the Eocene, they started looking familiar in various ways. Adapoids were diurnal and herbivorous and appeared larger than omomyoids. Which were mainly insectivorous, nocturnal and frugivorous. Both groups achieved considerable diversity in most of the regions in North America and Europe because of the presence of rainforest. Adapoids and omomyoids were forced to extinction due to increased seasonality that changed the mammalian biogeography. Anthropologists proved that “changing global climate has had profound effects on primate dispersal patterns and ecological habits over evolutionary time” (Shook, et al. 14). Human activities such as deforestation have caused a large number of primates to extinct. Many primates are “strongly tied to patches of trees and particular plant parts such as fruits, seeds, and immature leaves” (Shook, et al. 14) and therefore “the distribution of primates mirrors the distribution of forests” (Shook, et al. 14).