This is slightly misleading.
Here is how it actually works:
You have Allele A, which has a comparitive 3% fitness advantage (organisms with A have 1.03x more kids), meaning that it only takes ~768 generations in a population of 1 million (average human population, excluding the last 5,000 years) for A to become reliably present in the community.
At this point, Allele B, which depends on Allele A and has a comparitive 3% fitness advantage on its own, can start to spread amongst the population. After another 768 generations, it is a reliably present dependency.
After this, a modified version of A, which we will call A*, comes about, which is dependent on B and backwards-compatible with A, so B still works with the new A*, and A* has some comparitive fitness advantage so it spreads too.
Along comes C, dependant on B and A*, and then along comes B*, dependant on C and A*, and then along comes D, dependant on A* and B* and C... etc
at the end, you get a crazy fucked up archlinux-style dependency hell where if you remove one thing everything breaks, but this absolutely does not mean that the system could not have evolved incrementally. To say so is retarded.