Evolutionary Trend and Primate Taxonomy


Homo sapiens , the modern man, is unquestionably a primate and a distant cousin of monkeys and apes. Few people, nevertheless, are aware of their link. A little, nocturnal, insectivorous animal is most likely where the early primates originated. The two species that are most closely related to primates are tree shrews and colugos, commonly referred to as flying lemurs. The tree shrew serves as a live example of how early primates, or primate ancestors, could have looked. Primates or their predecessors entered the trees and adapted to an arboreal habitat at some time.


The two techniques that scientists employ to classify species are cladistics and conventional taxonomy. Biologists and palaeontologists both significantly rely on cladistics. Combining the two systems—specifically, the binomial nomenclature (genus and species) of conventional taxonomy and the cladistic ordering of species based on shared traits—has obvious advantages.

Strepsirhini and Haplorrhini are the two suborders that makeup primates.


  • They were the first suborder of primates to emerge.

  • Additionally, they are called "Prosimians" and "lower Primates."

  • Consists of a large, moist, hairless nose tip.

  • They are present throughout the majority of Madagascar's islands' tropical regions.

  • This group of lemurs consists of five lemur families.

Strepsirrhini (prosimians)

Infraorder Family
Lemuriformes(lemurs) Lemuridae
Lorisiformes(lorises) Indriidae


  • Regarded to be "higher monkeys" and referred to as "Anthropoids."

  • Monkeys make up more than 90% of them, with apes and humans making up the remaining 10%.

  • The most successful primates on Earth.






(Dry noses)

Infraorder Parvorder Superfamily Family





(New World monkeys)







(Old World monkeys,

apes and humans)



(Old World monkeys)




(apes andhumans)




Today, primates are often categorised according to their evolutionary past. This kind of classification is based on the scientific discipline of the phylogeny. It demonstrates how species are connected through shared ancestry. The phylogeny of primates is depicted in the tree below. At the top of the evolutionary tree are the conventional divisions of primates into prosimians and anthropoids for comparison. Several techniques are employed in analysing the phylogeny that is

  • Immunological Techniques

  • Molecular Approach

  • DNA Hybridisation

  • Mobile DNA Elements Approach

Major Events in Primate Evolution

  • The lineage from which contemporary lemurs and lorises descended split off from other early primates about 60 million years ago, marking the beginning of the first significant divergence.

  • It is believed that the common ancestor of contemporary monkeys, apes, and humans emerged approximately 40 million years ago. This event may have taken place in Asia as well. The first anthropoids, if they did originate in Asia, rapidly spread out into Africa.

  • At least 35 million years ago, the group of anthropoids that eventually gave rise to the contemporary New World monkeys diverged from their African relatives. The genus Aegyptopithecus, which existed between 35 and 33 million years ago, may have been the progenitor of Old World monkeys, apes, and humans.

  • By 23 million years ago, the Old World monkeys had separated from the group that now only consists of apes and humans. Proconsul africanus is a creature that may be the progenitor of both apes and humans.

  • The ultimate split between the chimpanzee and human lineages occurred in Africa some six million years ago. Not long after that, the first relatives of modern humans emerged.

Primate Evolutionary Trends

  • The development of the brain has been primates' primary evolutionary tendency. Comparative studies reveal a consistent upward trend in intellect, starting with prosimians and continuing through New World monkeys, Old World monkeys, apes, and ultimately humans.

  • The neocortex, which is the area of the brain responsible for sensory perception, the creation of motor orders, spatial thinking, and conscious cognition, is the section of the brain that has grown the most. Primates have extensive cognitive abilities due to their huge brains.

  • Their usage of tools is one sign of this. Some primates create tools. To "fish" for edible insects, chimpanzees, for instance, remove the leaves from twigs and place the twigs into termite mounds. Additionally, they file down wood to make spears for hunting small animals.

  • The evolution of primates has also shown a rising reliance on intricate social behaviour. The most sociable creatures are primates.

  • They cohabit in paired pairs, small family units, or communities of up to dozens of people. All members of the group are more likely to survive if everyone works together.


The ancestors of primates, an order of generalist mammals with adaptations for an arboreal lifestyle, initially appeared between 55 and 65 million years ago.

Based on morphology, primates have historically been divided into two main groups: prosimians (lemurs, lorises, and tarsiers), and anthropoids (monkeys, apes, and humans). Primate phylogeny uses molecular similarities to group primates based on their evolutionary histories. The development of the brain, particularly the neocortex, has been the primary evolutionary tendency in primates. The capacity of primates to utilise and create tools demonstrates their highly developed cognitive powers. A further evolutionary pattern in primates has been a growing reliance on sophisticated social activity.


Q1. Where did primates first emerge?

Ans. Around the start of the Eocene Epoch, around 55 million years ago or a little earlier, the first true primates appeared. Their fossils have been discovered throughout Asia, Europe, and North America.

Q2. What is the definition of a prehensile tail?

Ans. A well-adapted tail to hold or grasp objects is called prehensile. The primary function of this tail alteration is to help arboreal creatures grip food from trees. New World monkeys have prehensile tails.

Q3. What distinguishes a primate from a non-primate?

Ans. Primate animals have a big and sophisticated forebrain, whereas non-primate species have smaller brains. In addition, non-primates have an oestrous cycle rather than the typical menstrual cycle that a primate has.