1 can two species reproduce with each other?
2 Does variation occurs in same species due to sexual reproduction?
No. two species cannot reproduce with each other as the gametes of the different species are not compatible to fuse and form a new offspring.
Yes, variation can occur in same species due to sexual reproduction. This is so because gametes of two different individuals combine together in sexual reproduction. This combination of gametes gives rise to variations in the offsprings.