> do not individually confer any evolutionary advantage
Genes which do not confer any advantage are just as likely to spread as ones that do. Evolution doesn't select for advantages, it selects against disadvantages. Evolution is just an emergent property of death.
The point is that a mutation that causes no harm can persist, resulting in traits that serve no discernible function. Later on, multiple harmless but non-useful mutations might together make something interesting happen. Therefore the local maxima problem is not really a problem.
Genes which do not confer any advantage are just as likely to spread as ones that do. Evolution doesn't select for advantages, it selects against disadvantages. Evolution is just an emergent property of death.