When on
board H.M.S. Beagle, as naturalist, I was much struck with certain facts in the
distribution of the inhabitants of South America, and in the geological
relations of the present to the past inhabitants of that continent. These facts
seemed to me to throw some light on the origin of species—that mystery of
mysteries, as it has been called by one of our greatest philosophers. On my
return home, it occurred to me, in 1837, that something might perhaps be made
out on this question by patiently accumulating and reflecting on all sorts of
facts which could possibly have any bearing on it.
‘Humans evolved
from monkeys’ – is what we read / understood from school text books .. .. .. it
was surprising to see a monkey this morning at my terrace in Triplicane. It walked in a calm and composed manner, but
crows and other birds around were apparently agitated !!
Theory of Evolution
explaining how humans evolved - is the
lengthy process of change by which people originated from apelike ancestors!. There
are theories citing Scientific evidences that the physical and behavioral
traits shared by all people originated from apelike ancestors and evolved over
a period of approximately six million years.
Obviously, erect
Homo-sapiens, as we walk, took thousands of years to evolve. Human evolution, is the process by which
human beings developed on Earth from now-extinct primates. Viewed zoologically,
we humans are Homo sapiens, a culture-bearing upright-walking species that
lives on the ground and very likely first evolved in Africa about 315,000 years
ago! We are now the only living members
of what many zoologists refer to as the human tribe, Hominini, but there is
abundant fossil evidence to indicate that we were preceded for millions of
years by other hominins, such as Ardipithecus, Australopithecus, and other
species of Homo, and that our species also lived for a time contemporaneously
with at least one other member of our genus, H. neanderthalensis (the
Neanderthals). In addition, we and our predecessors have always shared Earth
with other apelike primates, from the modern-day gorilla to the long-extinct
Dryopithecus. That we and the extinct hominins are somehow related and that we
and the apes, both living and extinct, are also somehow related is accepted by
anthropologists and biologists everywhere.
Yet the exact nature of
our evolutionary relationships has been the subject of debate and investigation
since the great British naturalist Charles Darwin published his monumental book
– “origin of species’. The opening para is from the book of Charles Darwin, who
went on to state – ‘after five years'
work I allowed myself to speculate on the subject, and drew up some short notes
; these I enlarged in 1844 into a sketch of the conclusions, which then seemed
to me probable : from that period to the present day I have steadily pursued
the same object’. In his autobiography,
Darwin said he had "gained much by my delay in publishing from about 1839,
when the theory was clearly conceived, to 1859; and I lost nothing by it".
Charles
Robert Darwin FRS FRGS FLS FZS[2] [1809 – 1882]
was an English naturalist, geologist and biologist, best known for his
contributions to the science of evolution. His proposition that all species of life have
descended from common ancestors is now widely accepted and considered a
fundamental concept in science. In a joint publication with Alfred Russel
Wallace, he introduced his scientific theory that this branching pattern of
evolution resulted from a process that he called natural selection, in which
the struggle for existence has a similar effect to the artificial selection
involved in selective breeding. Darwin has been described as one of the most
influential figures in human history, and he was honoured by burial in Westminster
Abbey.
Darwin published his
theory of evolution with compelling evidence in his 1859 book On the Origin of
Species. By the 1870s, the scientific
community and a majority of the educated public had accepted evolution as a
fact. However, many favoured competing explanations which gave only a minor
role to natural selection, and it was not until the emergence of the modern
evolutionary synthesis from the 1930s to the 1950s that a broad consensus
developed in which natural selection was the basic mechanism of evolution. Darwin's
scientific discovery is the unifying theory of the life sciences, explaining
the diversity of life.
Darwin's early interest in
nature led him to neglect his medical education at the University of Edinburgh;
instead, he helped to investigate marine invertebrates. Studies at the
University of Cambridge (Christ's College) encouraged his passion for natural
science. His five-year voyage on HMS
Beagle established him as an eminent geologist whose observations and theories
supported Charles Lyell's conception of gradual geological change, and
publication of his journal of the voyage made him famous as a popular author. Puzzled
by the geographical distribution of wildlife and fossils he collected on the
voyage, Darwin began detailed investigations, and in 1838 conceived his theory
of natural selection.
In mid-July 1837 Darwin
started his "B" notebook on Transmutation of Species, and on page 36
wrote "I think" above his first evolutionary tree. In December 1831,
he joined the Beagle expedition as a gentleman naturalist and geologist. In late September 1838, he started reading
Thomas Malthus's An Essay on the Principle of Population with its statistical
argument that human populations, if unrestrained, breed beyond their means and
struggle to survive. Darwin related this to the struggle for existence among
wildlife.
On the
Origin of Species (or, more completely, On the Origin of Species by Means of
Natural Selection, or the Preservation of Favoured Races in the Struggle for
Life), published on 24 November 1859, is a work of scientific literature by
Charles Darwin that is considered to be the foundation of evolutionary biology.
The
book was written for non-specialist readers and attracted widespread interest
upon its publication. Darwin was already highly regarded as a scientist, so his
findings were taken seriously and the evidence he presented generated
scientific, philosophical, and religious discussion.
So a book published this time, 162 years ago, changed the way humans had perceived their own evolution ! interesting !
30th Nov. 2021.
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