The Surprising Origins of Evolutionary Complexity

Seems that Natural Selection isn't all there is when it comes to Evolutionary Complexity. Not a surprise for those who realize other Selections... It's a big step to place at the same level Sexual Selection an Natural Selection as engines of Evolutionary Complexity!

• Conventional wisdom holds that complex structures evolve from simpler ones, step-by-step, through a gradual evolutionary process, with Darwinian selection favoring intermediate forms along the way.
• But recently some scholars have proposed that complexity can arise by other means—as a side effect, for instance—even without natural selection to promote it.
• Studies suggest that random mutations that individually have no effect on an organism can fuel the emergence of complexity in a process known as constructive neutral evolution. 

https://www.scientificamerican.com/article/the-surprising-origins-of-evolutionary-complexity/