Regarding the mechanism and outcomes of variation, which statements are true?
a. Mutations are random and directionless, causing large differences that arise suddenly.
b. Darwinian variations are small and directional.
c. Saltation is the process where speciation occurs due to gradual accumulation of minor variations.
d. Genetic drift can sometimes lead to the original drifted population becoming founders (the founder effect).
e. The rate of appearance of new forms is linked to the life cycle or life span of the organism.
