More about how evolution works: more on patterns (Evolution)

by dhw, Friday, November 09, 2018, 12:26 (2204 days ago) @ David Turell

QUOTE: "Widely known simply as the Turing Model, RD is a theoretical construct used to explain self-regulated pattern formation in the developing animal embryo.

"The model, Cooper says, explains the progression of epithelial appendages – external structures such as hair, feathers, scales, spines and teeth – over at least 450 million years, a timeframe that spans the evolution of vertebrates.

"These structures, he says, all possess similar developmental positioning in relation to one another because they grow from a common foundation – the thickened areas of the epithelium known as placodes.

DAVID’s comment: Perhaps the diversity is not as diverse as it appears. More evidence patterns guide evolution. Easy to imagine a designer would set up patterns in advance. It helps explain convergence.

The article clearly illustrates common descent. I find it easy to imagine self-regulating cells/cell communities combining to form patterns and, as conditions change, changing their patterns in an ongoing process of variation and innovation. I don’t see patterns “guiding” evolution, but evolution resulting from organisms creating and varying patterns. Convergence simply means that organisms develop similar patterns to deal with similar conditions. What I find difficult to imagine is organisms developing (or in your hypothesis being given) new patterns in advance of the conditions that require or allow for change.