Question

Fill in the blanks: A goat which cannot walk properly can’t live for a long time. According to Darwin, this represents...................

Answer 1

Charles Robert Darwin was a great naturalist, geologist and biologist who was born in 1809 in England. He was known as ‘Father of Evolution’ due to his great work in evolutionary biology. The work of Darwin is known as Darwinism.

Complete answer:
-The work done by Darwin on evolution was first published in the year 1859 in his book titled ‘On the Origin of species’. Darwin explained his theory - origin of species by natural selection in this book. -According to this theory: -
-The individuals within each species are not similar to each other; rather they show dissimilarities in their physical characteristics. These dissimilarities are known as variations. Variations among individuals are due to dissimilarities in genes which in turn occur due to gene mutations.
Mutations are due to DNA damage, DNA replication, DNA repair or DNA recombination. Sexual reproduction is the main cause of variations as there is recombination of DNA.
-Some of these variations are hereditary and they are passed on to next generation i.e. from parents to offspring by genes. The transmission of these genes occurs independently to each other.
- In each generation, the number of offsprings produced is much more that that can survive Till the age of reaching sexual maturity (the age at which the organism can produce young ones). This increases the competition for food, space and reproduction. This is known as struggle for existence. Many individuals perished in this competition.
- The organisms that are fit are only able to survive in this competition and only they are able to reach sexual maturity and reproduce. The survival of such organisms is not at random. The individual or organisms that have characteristics (known as adaptations) that make them fit or best suited to tackle the environmental conditions are selected by nature to survive, reproduce and pass on their genes to next generation i.e. only fit individuals are selected by nature for survival. This is called natural selection and it helps in survival of fittest. The survived or fit individuals continue reproduction and gradually they evolve into new species. The unfit
individuals or individual that lack adaptations neither survive nor they pass their genes to next generations.
Thus according to this theory the goat which can’t walk properly will not be selected by nature for survival as it is unfit. So, a goat which cannot walk properly can’t live for a long time, according to Darwin, represents survival of the fittest.

Note: Darwin made his scientific studies about evolution on Galapagos Islands. Galapagos Islands are small volcanic islands in the Galapagos archipelago located in eastern Pacific Ocean. The islands are under the administrative boundaries of Ecuador. Darwin visited the islands five times to study evolution by a ship called HMS Beagle.