Cambrian Explosion: another article on early brains (Introduction)

by David Turell @, Friday, November 13, 2015, 19:45 (1703 days ago) @ David Turell

This on from Sci. Am. with interesting speculations. These brains appeared early and quickly once multicellularity with multiple organ systems appeared in the Cambrian.

http://blogs.scientificamerican.com/life-unbounded/500-million-year-old-brains-and-life...

"The three-part brain systems may be similar to those in modern insects, arachnids, crabs and lobsters, and appear to be preserved as thin films of carbon or iron oxide-based mineral discoloration. This is a remarkable discovery. The 520-million-year-old fossils come from the Cambrian period, the time in Earth's history where life seems to have undergone a number of profound transitions. That includes the 'Cambrian explosion' in multicellular diversity and the first discoverable remains of animal ancestral phyla.

"Exactly why these brains (dense collections of nerve cells and nerve networks) evolved at this time is open to speculation. But some researchers propose that the advent of multi-cellular life which had senses and complex body movements and contractions, including those positioned around feeding systems, would gain clear efficiency advantages with specialized and speedy nerve-like cells. Connecting and localizing these cells via nets and clumps would offer further gains, especially as novelties like hunting (and evading hunters) began to pop up in larger and larger bodied creatures.

"The bottom line is that the basic biological structures of brains emerged at least half a billion years ago, seemingly very soon after the emergence of truly complex multi-cellular life. Modern human brains may be very different than those ancient arthropod brains, but the evolutionary 'attractor' for specialized neural networks manifested itself a long time ago. (my bold)

Comment: The usual Darwinian explanations. They were required so they appeared. Really?


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