DNA studies topple the ladder of complexity (2014) (nautil.us)

Interesting that Wolfram predicted this in 2002, was mocked by Cosma Shalizi as having "absolutely no understanding of evolution"

According to Darwin's theory, don't organisms evolve simply in order to adapt (by natural selection) to their environment? Where did this belief in growing complexity come from? (Could it be perhaps just a crude reflection of the progressivist ethos of Modernity?)

This should be obvious? Complexity isn't an adaptation if it does not prove enough of an advantage to justify the increased maintenance and construction costs.

Biologist here : This belief of increasing complexity is just a relic of the times when we thought humans were the pinnacle of evolution.

It is a basic misunderstanding of evolution. The single-celled organisms of today have evolved longer. Their DNA has been mutating, adapting for 10-times longer than ours (as a species) has been.

There is no reason to think that they would be any more simpler than us. They are just adapted to different environments than us.

"Perhaps the fact that people are stunned whenever organisms become simpler says more about how the human mind organizes the world than about evolutionary processes. People are more comfortable envisioning increasing complexity through time instead of reversals or stasis. "

That's a W.E.I.R.D. thing to say...