Sep 6, 2023 04:35 PM
It's reassuring to think humans are evolution's ultimate destination, but research shows we may be an accident
https://theconversation.com/its-reassuri...ent-201048
EXCERPTS: Modern biologists agree that the most complex organisms have become more complex over the last 4 billion years, but they disagree about what sort of process accounts for this.
Because most organisms are still very simple, one possibility is that maximum complexity has increased “accidentally”, like the diffusion of a drop of ink in a glass of water. If true, this could be a blow to our human sense of significance as the most complex organisms.
Another theory is that increasing complexity is driven, on average, by natural selection. Sometimes selection acts on many, independent branches of the tree of life in a similar way and in parallel. This can produce similar effects in many of those branches and is known as a driven trend.
While driven trends need not imply divine purpose, they at least suggest that complexity was mostly an improvement, which is reassuring for us humans.
So which pattern is the most common in the evolution of complexity: accidental diffusion or driven trend?
[...] Our paper shows that increasing complexity in mammals has both diffusive and driven aspects. Rather than marching towards greater complexity, mammals evolved in lots of different directions, with only some lineages pushing the upper bounds of complexity.
Unfortunately, there is little research addressing this question. One of the few published studies demonstrates that crustaceans (crabs, lobsters, shrimps and their relatives) evolved with a driven trend for increasing complexity over the last half a billion years... (MORE - missing details)
https://theconversation.com/its-reassuri...ent-201048
EXCERPTS: Modern biologists agree that the most complex organisms have become more complex over the last 4 billion years, but they disagree about what sort of process accounts for this.
Because most organisms are still very simple, one possibility is that maximum complexity has increased “accidentally”, like the diffusion of a drop of ink in a glass of water. If true, this could be a blow to our human sense of significance as the most complex organisms.
Another theory is that increasing complexity is driven, on average, by natural selection. Sometimes selection acts on many, independent branches of the tree of life in a similar way and in parallel. This can produce similar effects in many of those branches and is known as a driven trend.
While driven trends need not imply divine purpose, they at least suggest that complexity was mostly an improvement, which is reassuring for us humans.
So which pattern is the most common in the evolution of complexity: accidental diffusion or driven trend?
[...] Our paper shows that increasing complexity in mammals has both diffusive and driven aspects. Rather than marching towards greater complexity, mammals evolved in lots of different directions, with only some lineages pushing the upper bounds of complexity.
Unfortunately, there is little research addressing this question. One of the few published studies demonstrates that crustaceans (crabs, lobsters, shrimps and their relatives) evolved with a driven trend for increasing complexity over the last half a billion years... (MORE - missing details)
