Given below are two statements: One is labelled as Assertion (A) and the other is labelled as Reason (R) :
Assertion (A) : Meiosis is the mechanism by which conservation of specific chromosome numbers of each species is achieved across generations in sexually reproducing organisms.
Reason (R) : Variations are very important for the process of evolution. 
In the light of the above statements, choose the most appropriate answer from the options given below :

Both A and R are correct but R is not the correct explanation of A.
Assertion (A) is correct because meiosis is indeed the process by which the specific chromosome number of each species is maintained across generations in sexually reproducing organisms. During meiosis, the diploid (2n) parent cell undergoes two successive divisions (meiosis I and meiosis II) to produce haploid (n) daughter cells. This reduction in chromosome number ensures that when gametes (sperm and egg cells) fuse during fertilization, the resulting zygote will have the correct diploid chromosome number characteristic of the species.

Reason (R) is also correct because variations generated during meiosis are indeed essential for the process of evolution. Meiosis introduces genetic variation in offspring through several mechanisms, including independent assortment of homologous chromosomes, crossing over during prophase I, and random fertilization. These processes result in genetic diversity among individuals within a population, which is crucial for natural selection and adaptation to changing environments over successive generations.