How to study Darwin’s Theory
for MH-CET 2014
Darwin’s theory of Natural selection and the objections raised against it
Darwin’s theory of Natural selection is based on the following principles:
i. Over production or enormous fertility or prodigality of production: Every
living organism has a great potentiality of reproduction. Therefore, they produce
many young ones but only few can survive up to maturity. Any population tends to
increase in geometrical proportion causing over production of its members.
ii. Struggle for existence: Organisms multiply in geometric ratio but the space and
food remain constant leading to competition for survival. This competition is
called struggle for existence. The struggle may be intraspecific, interspecific or
iii. Variations and heredity: Variations are the differences between individuals of
the same species. Variations may be harmful, neutral or useful variations, i.e. they
can be favourable variations and unfavourable variations. The useful variations, are
preserved and passed on to their offsprings.
iv. Survival of the fittest or Natural selection: The organisms having useful and
favourable variations succeed in the struggle for existence. These organisms are
the fittest for survival. While the organisms with unfavourable variations are unfit
to survive and thus nature does not select them. This is called survival of the fittest.
Since the nature selects the organisms which are provided with favourable
variations hence the theory is known as the theory of Natural selection.
v. Origin of new species: A new species originates by the gradual accumulation of
favourable variations for a number of generations. Nature selects organisms with
favourable variations which have better chance for survival. The favourable
characters are transmitted to the next generation. Due to gradual changes in the
organism after many generations the descendants appear to be different from their
ancestors. These different forms of organisms are identified as new species.
Objections to Darwin’s theory of Natural selection: The objections raised
against Darwin’s theory of Natural selection are as follows:
i. Darwin could not explain ‘the arrival of the fittest’. He simply insisted on
survival of the fittest.
ii. He did not consider the hereditary principles.
iii. He did not differentiate between somatic and germinal variations.
iv. This theory has no satisfactory explanation for the cause, origin and inheritance
v. Darwin’s theory of Natural selection does not give any idea about the
inheritance of useless variations like the vestigial organs.
Keep on visiting www.ednexa.com for more study material about MH-CET
- Team Ednexa