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MAN’S FAMILY TREE. 5A7 
the human stem as breaking away from that leading on to the gorilla and chimpanzee 
rather more than half-way through the Tertiary period. He did not attempt to 
estimate the duration of geological periods in years, but in order that we may form 
some estimate of the antiquity of man or pre-man as depicted in Haeckel’s tree— 
we may apply what is the most acceptable of modern estimates, that given by Dr. 
H. Fairfield Osborn. On the Osborn scale of reckoning 60 million of years are supposed 
to have elapsed between the appearance of primates at the beginning of the eocene 
and the full evolution of man in the present or Quaternary period. On this reckoning 
Haeckel gives the antiquity of man—that is the date at which the human separated 
from the anthropoid phylum—as some 20 or 25 million of years. He represents the 
great anthropoid phylum as breaking away from that of the small anthropoid deep 
in the oligocene, the small anthropoid parting from the monkey deep in the eocene, 
and the monkey stem from the basal stem just before the dawn of the Tertiary period 
of the earth’s history. Thus, to transmute an early primate form into modern man 
has occupied nature’s evolutionary processes an zon of time—some 60 million of years 
if we apply Osborn’s reckoning to the family tree drafted by Haeckel. Looking at 
this first attempt in the light of the facts now at our disposal, we marvel at the accuracy 
of Haeckel’s intuition. 
By 1874 (Anthropogenic) Haeckel gave his tree of life a new shape. His original 
tree (1866) was flat topped, its branches streaming in one direction under the stress 
of the winds of evolution ; it was a lopsided tree. His new tree of life resembled a 
massive gnarled oak, with a single main trunk giving off many branches from each 
side and ultimately ending at the extreme top in a crown of twigs—the human family. 
Just under the top issued the anthropoid branches. Such a tree seems to me to 
reflect human vanity rather than zoological justice. It conveys a totally wrong 
impression of man’s relationship to the animal kingdom. It leads the spectator to 
conclude that the tree of life has grown and groaned all through these past geological 
zeons just to produce humanity as its topmost shoots, and that all forms of life are but 
abortive branches of the great human stem. This anthropocentric tree of life was 
introduced by Haeckel. It has still its advocates. And if we accept such a tree as 
a representation of reality, then it is but just to regard these branches which emerge 
just short of the top and represent anthropoid types of primates as abortive attempts 
at man-production. 
I have dealt thus fully with Haeckel’s family tree not only for the reason that it 
represents the first of human genealogies, but more especially because it has given 
me, an opportunity of discussing the manner in which evolutionary pedigrees are 
drafted. We must now leave these early attempts of Haeckel behind us and note 
the chief changes which have had to be made from time to time as new evidence 
came to light. Haeckel lived to see many of these changes introduced ; he died in 
1919 at the age of 85. First let me show you the pedigree which Dr. Eugen Dubois 
drafted of the highest primates in 1895. He wished to depict the position which he 
assigned to the fossil form of being he had discovered in Java to which he gave the 
name Pithecanthropus erectus. He adopted Haeckel’s anthropocentric scheme and 
gave man’s line of ascent the central place in his diagram. The central stem is 
represented at first by a Proceropitheque, the prototype or ancestor of the old-world 
monkeys. Then follows a stage represented by Prothylobates—the ancestor of the 
gibbons; then the stem ascends to become the prototype of the great anthropoid 
apes. This, as it ascends, becomes the Pithecanthropic type, and finally the stem 
ends in the human form. Dubois originally regarded the fossil being he found in 
Java as a transitional form between the protoanthropoids and man, and hence gave 
his discovery a place on the direct line of human ascent. It is a remarkable fact that 
in the human pedigree which Haeckel drew in 1879 he postulated such an intermediate 
stage, and gave to this hypothetical ancestor of man the name Pithecanthropus—a 
representative of speechless man. Dubois was impressed by the many gibbon-like 
features of Pithecanthropus, and hence he made the stock of gibbons or small 
anthropoids diverge from the main or human stem high up, just below the emergence 
_ of the great anthropoid branches. 
Some years before Dubois published his family tree (Nature 1895, vol. liii., p. 245) 
I had been dissecting apes and collecting published records in order to make a more 
complete census of the anatomical characters of the higher primates than had been 
done by my predecessors. Altogether I had dissections of-some 300 animals at my 
disposal—gorillas, chimpanzees, orangs, gibbons, old-world monkeys and new-world 
monkeys. Records of human dissections were already plentiful. Imade this extensive 
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