Original organisers

western model predicted the site of two other tropical kelp species off Cabo Frio in Brazil. The researchers also came across a reference to another deep-water kelp species off the Philippines. This species was last known to science following collection from a site predicted by the model to be suitable for tropical kelp. With these predictions to hand, the team decided earlier this year to mount an expedition to the Galapagos to look more carefully for kelp at the sites predicted by their model. Only limited observations of the local species, Eisenia galapagensis, had occurred since its original description in 1945 with specimens largely confined to just one site after the El Niño event of 1982–1983. The researchers' model however, predicted large areas of suitable habitat around the archipelago, with the largest areas predicted along the west coast of Isla Fernandina and the southwest coast of Isla Isabela. And indeed, through scuba dives, the team were able to find kelp populations at predicted sites up to a maximum dive depth of 60 metres. The team were unable to explore any deeper but noted that specimens growing at 50–60 metres were denser, larger and healthier than shallower-growing specimens. The researchers believe that the predictions of their model and their dive findings suggest that these kelp populations may be old and resilient features of the tropical seas. They point out that the Philippines species is the most morphologically and ultrastructurally primitive of current kelp species. " The global significance of these systems likely extends beyond simple ecological curiosity with broader impacts to tropical sublittoral systems worldwide, " they write. Kelp forests may " develop unique communities relative to other tropical systems " , they believe. Original organisers An old tenet holds that in science there's nothing as much fun as taking an experiment that works and doing it over and over again. While such unoriginality would be the end of any career in the arts, in science it can be rewarding. Writing in this issue of Current Biology, Ulrich Technau and colleagues took a well-established experiment — Spemann and Mangold's amphibian organiser transplant — and repeated it in a distantly related animal. But going beyond repetition, their work suggests that the evolution of the organiser might predate the origin of the chordates. In the mid 1920s, Hans Spemann and Hilde Mangold transplanted parts of one early newt embryo to another, among them …