Cambrian Explosion: Ediacarans ae so simple (Introduction)

by David Turell , Saturday, January 08, 2022, 19:02 (1050 days ago) @ David Turell

A new intensive study finds them sessile and passive feeders depending on water currents:

https://phys.org/news/2022-01-combine-paleontology-fluid-physics-uncover.html

"Their research features strange, vase-like organisms (in the genus Ernietta) that lived in the Ediacaran era—approximately 635 million to 541 million years ago. These organisms lived in marine environments, where fluid dynamics drive the evolution of the organisms that inhabit them.

"This work brought two distinct areas of science together—paleontology and fluid dynamics, which describes the flow of liquids and gasses. "Paleontology is at its most exciting—and arguably most successful—when it works at the interface with other disciplines. In this case, it's fluid physics," Darroch said.

"Computer models of fluid dynamics that affect communities of organisms suggest that when isolated, larger individuals have better nutrient circulation in their body cavities than smaller individuals. However, when different sizes of individuals live together, larger ones can create beneficial conditions for smaller ones that are downstream. Gibson led this research, conducted within the Evolutionary Studies Initiative,

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"'Perhaps the greatest benefit is that smaller Ernietta would be protected from adverse flow when downstream of larger ones, but they also consistently receive stronger cavity recirculation (probably aids in suspension feeding)," Gibson said. "Our simulations suggest that these sorts of ecological dynamics, which are well-known in living animals, also helped to structure Ediacaran communities composed of organisms that are entirely mysterious to us.'"

Comment: it is obvious how different an early Cambrian was like, as they actively hunted for food. Not the normal small step advance in evolution, which demands the recognition of fresh design.