(a) Mendel introduced mathematics into biology. Till then biology was mainly thought of as a descriptive science and people could not appreciate Mendel’s uniqueness of using mathematics in biology. Mendel’s monohybrid ratio is in fact nothing but the expansion of the First bionomial of algebra.
(b) Mendel lived in a country which was not politically dominant. At that time British Empire and particularly Great Britain was almost the centre of the world’s interest and any contribution from there used to attract worldwide attention.
Again during that time, the whole intellectual world was busily engaged in discussing Charles Darwin’s evolutionary theory which seemed to question the unique position that man had given to himself in the biological world.
It is a strange irony that Charles Darwin was not aware of the existence of Mendel much less of his work had only Darwin knew about Mendel’s work, he (Darwin) would have greatly modified his theory on evolutionary mechanism.
The uniqueness of Mendel’s work not only lies in propounding the few of inheritance but also in providing an explanation for the origin of heritable variations. Darwin evaded the most fundamental aspect in the mechanism of evolution namely the origin of heritable variations.
Mendel provided an answer in the form of producing new heritable variations from the existing ones. The basic variation however has to be brought about by mutation.
Mendel explained the means, whereby variations present in different individuals get distributed, undergo various permutation combinations thus producing new traits.
What Mendel did with the pea plants i.e. Hybridization, has been going on in nature ever since life began, to produce myriads of forms and expressions of life.