550 million years of chordate evolution

Check it out. Also in Nature June 19.

With the aim of understanding the evolution of chordates, the JGI sequenced the amphioxus genome .... A thorough analysis ... shows that the creature's 19 chromosomes map onto the human genome in 17 segments, each of which is represented four times in the human genome.

"The human genome is a mosaic of these 17 ancestral pieces constructed by two rounds of duplication, followed by gene loss and chromosome rearrangments and fusions. That took some computational gymnastics to sort out, but the evidence is still there," said Rokhsar.

Interesting Illusions

These are from the Best Illusion of 2008 Contest.
They each show something cool about our perception.





"Filling in the Afterimage after the Image" (I could not get Blogger to accept the link to the animation; get it from the contest page) shows that (in my interpretation) the retina sees the 8-pointed figure as a superposition of two uniformly colored 4-pointed stars, and produces the corresponding afterimages.






"Dramatically Different Percepts between Foveal and Peripheral Vision" tells it all. (Again, link to animation from the contest page).