Human Evolution, Apes to Man

Human Evolution is studied in anthropology.
Genology: the orderly sequencing of evolutionary phases
T.H. Huxley made the first attempt to explain the genesis of man using science in his book “The place of man in nature “
The book Descent of Man contains Charles Darwin’s theories about the origins of man.
Man was given the scientific term “Homo sapiens” by Linnaeus.
Men were described by Lucretius as “babies birthed out of the womb of Earth.”
Mammals descended from therapsid reptiles of the Mesozoic era’s Triassic epoch.
Egg-laying prototherians, which descended from reptiles during the Cretaceous period of the Mesozoic era, were the first primitive mammals.
Primates are a class of mammals that include humans, and they first appeared in the Paleocene epoch of the Tertiary Period of the Cenozoic Era.

Order primate include sub order Anthropoids and Prosomian.

Include 3 superfamilies

New world monkey (Ceboidea)

	New World Monkey (Platyrrhini)	Old World Monkey (Catarrhini)
Nose and Nostrils	Flat noses with widely separated and outwardly directed nostrils	Narrow noses with closely placed and downwardly directed nostrils
Tails	Posses long prehensile tails	Short non-prehensile tails
Use of limbs	Limbs not used for grasping	Limbs well adapted for grasping
Dentition	Primitive dentition like prosimian ancestors; 3 molars and 3 premolars in each half of jaw	Dentition more like man; 2 premolar 3 molar in each half of jaw
Molar cusps	They have 3 cusps (elevation in the crown of teeth) in molars	Have 4 or 5 cusps in molars
Brain	Less developed and unspecialized brain	Better developed and specialized brain , lesser lumbar vertebrae, smaller pinnae, sensitive fingertips, continuous spermatogenesis, menstrual cycle, and capable of expressing of emotions by facial gestures.
Origin	Native to South America	Native to Asia and Africa
Examples	Marmosets, Spider Monkey, etc.	Baboons, Proboscis Monkeys, etc.

Four types of apes have survived till today:

Brain to body weight ratio of Apes is 1:250
The diploid no. of chromosomes in Gorilla, Chimpanzee and Orangutan (pongids) is 48.
The banding pattern and chromosome number best explains the common origin of Man and Chimpanzee.

Important Hominoids are:

Homo erectus pekinensis or Pithecanthropous pekinensis or Sinanthropous pekinensis
Middle Pleistocene
Discovered by W.C. Pie
Cranial capacity 1075 cc

Periods of cultural evolution have been divided into

	Apes	Man
Habitat	Semi arboreal	Terrestrial
Limbs	Fore limbs longer than Hind limbs	Hind limbs/legs are powerful, stout and more developed than fore limbs
Posture	Body posture bent and require fore limbs for movement	Body posture erect and fore limbs free during locomotion
Head	Head is balanced on heavy shoulder and found buried	Head is erect and balanced on neck
Skull and Forehead	Fore head and skull are flat	Fore head is large , protruded; Skull, dome shaped.
Posture	Lumbar curve not found in vertebral column	Lumbar curve present, which facilitate erect posture
Lowe jaw	Lower jaw are heavy, teeth large, chin rounded and not prominent	Lower jaw is small, teeth small, chin flat and prominent
Eye brow	Eye brow ridges are heavy and protruded	Eye brow ridges are thin and not protruded
Head movement	Neck muscle attached to back of skull, hence head movement limited	Neck muscle attached below skull, hence hence movement wider range
Big Toes	Big toes in feet opposable; used for grasping	Big toes not opposable, do not help in grasping
Feet	During locomotion, soles do not touch ground, only outer ridges of fore and hind limbs	During locomotion, the soles except the bridges of feet touch the ground
Cranial capacity	Cranial capacity small. Gibbon (100 cc), Orangutan (395 cc), Chimpanzee (400 cc), Gorilla (510 cc)	Cranium is large and large cranial capacity unto 1600 cc
Examples	Gibbon, Orangutan, Chimpanzee and Gorilla	Human