Charles Darwin based his theory on various
observations he made as a young naturalist on board the
H.M.S Beagle, which sailed in late 1831 on a five-year official
voyage around the world. Young Darwin was heavily influenced
by the diversity of species he observed, especially of the
different Galapagos Island finches. The differences in the
beaks of these birds, Darwin thought, were a result of their
adaptation to their different environments.
After this voyage, Darwin started to visit
animal markets in England. He observed that breeders produced
new breeds of cow by mating animals with different characteristics.
This experience, together with the different finch species
he observed in the Galapagos Islands, contributed to the
formulation of his theory. In 1859, he published his views
in his book The Origin of Species. In this book, he postulated
that all species had descended from a single ancestor, evolving
from one another over time by slight variations.
What made Darwin's theory different from Lamarck's
was his emphasis on "natural selection." Darwin theorized
that there is a struggle for survival in nature, and that
natural selection is the survival of strong species, which
can adapt to their environment. Darwin adopted the following
line of reasoning:
Within a particular species, there are natural
and coincidental variations. For instance some cows are
bigger than others, while some have darker colors. Natural
selection selects the favorable traits. The process of natural
selection thus causes an increase of favorable genes within
a population, which results in the features of that population
being better adapted to local conditions. Over time these
changes may be significant enough to cause a new species
Charles Darwin developed his
theory when science was still in a primitive state.
Under primitive microscopes like these, life appeared
to have a very simple structure. This error formed
the basis of Darwinism.
However, this "theory of evolution by natural
selection" gave rise to doubts from the very first:
1- What were the "natural and coincidental
variations" referred to by Darwin? It was true that some
cows were bigger than others, while some had darker colors,
yet how could these variations provide an explanation for
the diversity in animal and plant species?
2- Darwin asserted that "Living beings
evolved gradually." In this case, there should have lived
millions of "transitional forms." Yet there was no trace
of these theoretical creatures in the fossil record. Darwin
gave considerable thought to this problem, and eventually
arrived at the conclusion that "further research would provide
3- How could natural selection explain
complex organs, such as eyes, ears or wings? How can it
be advocated that these organs evolved gradually, bearing
in mind that they would fail to function if they had even
a single part missing?
4- Before considering these questions,
consider the following: How did the first organism, the
so-called ancestor of all species according to Darwin, come
into existence? Could natural processes give life to something
which was originally inanimate?
Darwin was, at least, aware of some these questions,
as can be seen from the chapter "Difficulties of the Theory."
However, the answers he provided had no scientific validity.
H.S. Lipson, a British physicist, makes the following comments
about these "difficulties" of Darwin's:
On reading The Origin of Species,
I found that Darwin was much less sure himself than he is
often represented to be; the chapter entitled "Difficulties
on Theory" for example, shows considerable self-doubt. As
a physicist, I was particularly intrigued by his comments
on how the eye would have arisen.1
Darwin invested all his hopes in advanced scientific
research, which he expected to dispel the "difficulties
of the theory." However, contrary to his expectations, more
recent scientific findings have merely increased these difficulties.