All variations in a species do not have equal chances of survival. Some of the variations may be so drastic that the new DNA copy cannot work with the cellular apparatus it inherits. Such, a new born cell dies soon.

Depending on the nature of variations, different individual will have different kinds of advantage. Variations results from change in genetic composition. Advantageous variations are selected by environmental factors. This leads to evolution and speciation.

In asexual reproduction, the variations that occur due to sexual reproduction are absent but may occur due to mutations.

So, the correct answer is 'All variations in a species have equal chance of survival'