The history of human culture, in which the history of science is an important, reveals at first a very slow growth with roots in the remote past.
In his various biological aspects man shows evidence of descent from ancestor related to the great apes.
Many facts suggest a vast area in south central Asia north of the Himalayan mountains as the place where the human stem arose.
The time when our ancestors became really human probably could not be stated definitely, even if all the circumstances were known, for the change must have been a very gradual one.
However, it certainly was completed before the beginning of the Pleistocene.
The geological epoch, following the Pliocene and preceding our own Recent Epoch, was distinguished by extraordinary cooling of the earth.
Four times great ice sheets spread southward over lands of the northern hemisphere, and four times they related.
During each of these Ice Ages, distinctive mammals appeared, some of gigantic proportions, and their skeleton, buried by dust storms or in the sediments of the swollen of the warm interglacial ages, enable geologist to recognize deposits laid down in any one age.
On other evidence, geologists estimate the length of these ages in years and the whole epoch is believed by American authorities to have lasted a million years ending about twenty-five thousand years ago.
Very early in the Pleistocene primitive men were living in widely separated localities, probably migrants escaping competition with more progressive races at home.
The most primitive of these is the Trinil man (Pithecanthropus) of Java. He was very ape-like, but recent discoveries (1937) shown anatomical features that distinctively human.
There is however no evidence of distinctively human behavior. It is different with Peking man (Sinanthropus), who inhibited caves eastern China at about the same time.
He had larger brain, and he made tools and fire, - activities as distinctively human as articulate speech.
When he learned a kindle a fire from sparks that flew as he chipped flints to make his crude implements, he made the first application of a physical principle to human needs.
Perhaps earlier in time, but with more modern features the Piltdown man (Eoanthropus) was established in southeastern England in the Pliocene or earliest Pleistocene.
A somewhat later type, of Mid-Pleistocene age, the Neanderthal, pursing the great beasts, overran Europe during the second interglacial period. Around their camp fires they made the first completely flaked flint implement, the hand ax- tool characteristic of the Old Stone Age, Paleolithic.
They in turn, gave way during the last Ice Age, perhaps 150,000 years ago, to modern man Homo sapiens, represented by the Brunn and Co-Magnon races.
The latter left in numerous cave dwellings implements of flint and bone and drawing and sculptures, showing fine powers or observation and great manual dexterity.
The Antiquity and Ancestry of Man
