Evolution: not always simple to complex (Introduction)

by David Turell , Thursday, November 10, 2022, 20:20 (742 days ago) @ David Turell

One animal proves the point:

https://phys.org/news/2022-11-ancient-simple.html

"Researchers at the University of Nottingham have solved an important piece of the animal evolution puzzle as their new study reveals that our ancient ancestors were more complex than originally thought.

"Way back in our distant evolutionary history, animals underwent a major innovation. They evolved to have a left and right side, and two gut openings. This brought about a plethora of significant advantages in terms of propelling themselves directly forward at increased speed through the early seas, finding food, extracting nutrients, and/or avoiding being eaten.

"It was such a successful strategy that, today, we share our planet with a huge diversity of other animals with bilateral symmetry and two gut openings just like us. They include animals as diverse as starfish, sea cucumbers, elephants, humans, crickets, and snails. They also include an enigmatic group of very simple marine worms called Xenacoelomorphs, who lack many of the complex features of their fancier looking cousins.

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"For years, scientists have debated who is more closely related to who in this diverse collection of bilaterally symmetrical animals. Some experts argue that Xenacoelomorphs mark the first group to branch in that major jump in innovation from animals with circular body plans (e.g. jelly fish and corals) to bilateral symmetry. If this was the case, then the first bilaterian itself was also a very simple animal. Others argued for different placements of Xenacoelomorphs on the family tree.

"However, a research team, led by Dr. Mary O'Connell at the University of Nottingham has found that Xenacoelomorphs branch much later in time, they are not the earliest branch on the bilaterian family tree, and their closest relatives are far more complex animals like star fish. This means that Xenacoelomorphs have lost many of the complex features of their closest relatives, challenging the idea that evolution leads to ever more complex and intricate forms. Instead, the new study shows that loss of features is an important factor in driving evolution."

Comment: if a designer is involved, He can take any direction He wishes, just like the jump in Cambrian forms. And yes, to forestall the obvious, this jumping around suggests free-for-all if your thinking is skewed toward a human-like God.