Today, people are no longer unfamiliar with the evolution from ape to human. Curious humans still want to know when, where, and from which animals these apes evolved into humans. This is one of the most popular research topics in paleontology today: the origin of higher primates.
lemur
The primate family, to which we humans belong, is divided into lower primates and higher primates.
Lower primates are known in animal taxonomy as the suborder Anthropoidea, which appeared as early as the end of the Cretaceous period, more than 65 million years ago. To this day, three suborders of prosimians still inhabit the Earth: the lemur suborder, whose distribution is limited to Madagascar; the elongated monkey suborder, which lives in the forests of Africa and South Asia; and the tarsiers suborder, which are distributed on some islands in Southeast Asia.
Higher primates are classified as the suborder Anthropoidea in animal taxonomy. Their extant groups include the infraorder Proboscis (also known as New World monkeys) which live in the Americas and the infraorder Acroproboscis (also known as Old World monkeys) which are distributed in Eurasia and Africa. The infraorder Acroproboscis includes two superfamilies—the superfamily Macea and the superfamily Anthropoidea; the superfamily Anthropoidea includes the families Pheasantidae and Hominidae.
Higher primates undoubtedly originated from lower primates. But from which lower primates did they originate? And what were the time and place of origin? These are the questions that paleontologists and primatologists have to answer.
Tarsiers
Among these three suborders of lower primates, tarsiers share the greatest similarity with higher primates in both morphology and DNA sequence. Therefore, many scientists believe that higher primates and tarsiers are most closely related. Based on this, and combined with some fossil evidence, many scholars speculate that both tarsiers and higher primates originated from an ancient lower primate called *Eopterus*; however, *Eopterus* diverged from the ancestors of other lower primates long ago on the evolutionary path.
However, until the 1990s, the earliest fossil evidence of higher primates discovered by scientists consisted of animals from the Fayoum region of Egypt that lived approximately 35 million years ago (Late Eocene). These animals shared many morphological similarities with the pseudo-striker (a primitive lemur) discovered in North America during the Eocene. Therefore, some paleontologists maintained that higher primates originated from lemurs, specifically in Africa. Furthermore, since the earliest recognized human ancestor, Australopithecus, also originated in Africa, and the "mitochondrial Eve hypothesis" posits Africa as the origin of modern humans, the African origin theory of higher primates aligns with the idea that the story of human origins and development has repeatedly unfolded the "Out of Africa" narrative.
Clearly, there have been contradictions between the biological evidence provided by extant species and the paleontological evidence provided by the fossil record regarding the origin of higher primates; the two major schools of thought, the primate origin theory and the lemur origin theory, each held their own views. The question of the origin of higher primates, already a hot topic of scientific research, attracted even greater attention in the 1990s.
