The Human Evolutionary Tree
Origins of Mankind
Since Darwin's publication of his "Origin of Species" there has been a increasingly widespead acceptance, particularly in the
'westernised' parts of the world,
of the idea that Mankind 'evolved' from earlier forms of life that were,
long, long, ago
more like lemurs or monkeys than Human Beings.
This graphic shows such a popularly accepted Monkey to Man progression.
The scientific view of the origins of species, which has contributed to the secularisation of the west by inherently
posing difficult questions to faith, holds that there were many naturally occuring changes in physique and behaviour - some of
these proved beneficial in terms
of survival - and were locally reinforced by such "successes-in-survival" allowing several branching divergences,
based on these survival-favouring changes,
to produce an evolutionary tree of related species - including mankind!
The following graphic demonstrates something of the Darwininian / Scientific approach to describing the Human Evolutionary Tree.
Source : The National Museum of Natural History - Washington, D.C.
Science holds that existing primate species can be divided into six subgroups: lemurs, lorises, tarsiers, New World monkeys, Old World monkeys,
and apes and humans.
Science further holds that the changes that allowed Humans to feature as part of a primate / human evolutionary tree, and which allowed Humanity
to become established as
we know it today, were very slowly accumulated due to various "survival advantages" that these changes
conferred allowing their possessors to be more generally successful in the struggle for life but particularly
so in the gaining of foodstuffs to nourish themselves, their families, and their friends.
The concept of a Human Evolutionary Tree is itself very directly related to more generalised Tree of Life concepts which lie at the heart
of Darwinian Evolutionary
Theory.
As early as July 1837 Darwin opened a notebook to record his thoughts on "that mystery of mysteries - the origin of species" as this entry from
his diary
relates:-
In July I opened my first note-book for facts in relation to the Origin of Species, about which I had long reflected, and never
ceased working on it for the next twenty years.
The direction of the development of Darwin's thoughts can perhaps be illustrated by this famous
Tree of Life sketch from his Notebook B dating from 1837-8:-
Charles Darwin's early evolutionary theory insight of how a branching tree-like genus of related species might
originate by divergence from a starting point (1) to effectively establish related species at such notional points as A, B, C and D.
There is an accompanying text annotation, from Darwin's notebook B now stored in Cambridge University library, that reads:-
I think
Case must be that one generation then should be as many living as now. To do this & to have many
species in same genus (as is) requires extinction.
Thus between A & B immense gap of relation. C & B the finest gradation, B & D rather greater
distinction. Thus genera would be formed. — bearing relation (page 36 ends - page 37 begins)
to ancient types with several extinct forms.
Although Charles Darwin seems to have formed his initial evolutionist hunches in or around 1835 his most famous work on the
Origin of Species was not published until 1859.
His chapter summary to "Chapter IV. Natural Selection" in the Origin of Species features this - Tree of Life - related assertion:-
The affinities of all the beings of the
same class have sometimes been represented by a great tree. I believe this
simile largely speaks the truth. The green and budding twigs may represent
existing species; and those produced during former years may represent the
long succession of extinct species. At each period of growth all the
growing twigs have tried to branch out on all sides, and to overtop and
kill the surrounding twigs and branches, in the same manner as species and
groups of species have at all times overmastered other species in the
great battle for life. The limbs divided into great branches, and these
into lesser and lesser branches, were themselves once, when the tree was
young, budding twigs; and this connexion of the former and present buds by
ramifying branches may well represent the classification of all extinct
and living species in groups subordinate to groups. Of the many twigs
which flourished when the tree was a mere bush, only two or three, now
grown into great branches, yet survive and bear the other branches; so
with the species which lived during long-past geological periods, very few
have left living and modified descendants.
The Human Evolutionary Tree, seen from this 'Darwinian Theoretical' perspective, becomes rather a branch of a mind-blowingly ancient
general Tree of Life.
In his work of 1859, issued as it was into a fairly faith-accepting victorian England, Darwin avoided
speculating that Human Beings were themselves subject to evolutionary processes.
Nevertheless, despite much controversy, the view that Humans also 'evolved' gradually gained an increasing acceptance - with consequences
for religious belief - as scientifically inclined contemporaries such as Thomas Henry Huxley ventured to explicitly suggest,
(in his Evidence as to Man's Place in Nature published in 1863), that Human Beings
were themselves a species that was itself closely related to some ape species.
Darwinism and Evolutionary Science in the "westernised" world has now substantially accepted, for well over a century, that Humans
have 'evolved' and that there is a Primate / Human evolutionary tree of closely related species.
Artistic spoof on the proposed human evolutionary tree
depicting a modern man on a steel branch.
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