LOL cnidarians


Read LOL Cnidarians on Tangled Up in Blue Guy. He describes two new discoveries in evolution:

  1. Light sensitivity developed in hydras, a group that includes tiny water animals (pictured) and jellyfish.
  2. The proteins for a nervous system occur in sponges (who don’t have one). The first nervous system evolved in cnidarians.

Sponges separated from cnidarians about 600 million years ago, so that puts a time estimate on both those developments.

Ha!


New research on monkeys suggests that the brain is hard-wired to mull over decisions even after they’ve been made.

The researchers, led by Howard Hughes Medical Institute international research scholar Ranulfo Romo, reported their findings in the October 16, 2007, issue of the Proceedings of the National Academy of Sciences. Romo and his colleagues are at the National Autonomous University of Mexico….

“To our surprise, when the monkeys held the decision for several seconds, what we saw in the activity of these brain cells in the medial premotor cortex is that they were still remembering the sensory information on which the decision was based,” said Romo. “During that time the neurons were recalling the first stimulus, recalling the second, comparing the second against the first, and even reporting in their activity the categorical decision.”

The researchers’ measurements showed that neurons in the medial premotor cortex were switching back and forth between encoding the sensory information and the decision. “It is a dynamic process, as if the monkeys were constantly trying to revise or update their decision. So, whether it is conscious or unconscious, the working memory is still `brewing’ the perceptions that led to the categorical decision,” he said.

So it’s not just me being wishy-washy.

James Watson opens mouth to change feet

James Watson, one of the discoverers of DNA, is not thereby immune from being wrong or even wrong-headed. By all accounts, he’s a bit of a jerk*. But still, people were shocked when he announced that African races were not as intelligent as melanin-deficient ones. He ignored alternative explanations, such as cultural effects. And even if there were an innate average difference in general intelligence, it would be swamped many times over by individual differences. It’s not the only time he’s put his foot in it. Recently he’s been suggesting that darker skin means a higher sex drive and illustrating his lectures with pictures of bikini-clad women. This suggests to me that he’s reached his dotage and has started re-living his ignorant youth when such attitudes were more prevalent.

Now, people are refusing to listen to his nonsense. One of his lectures in London, previously sold out, has been cancelled by the organizers.

*See Rosalind Franklin and DNA.

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