Thursday, February 19, 2009
Chelicerata Morphing Evolution
Chelicerata is the class of arthropods whose members are characterized by appendages (chelicerae) that appear before the mouth. The class includes species of spiders, ticks, mites, scorpions, horseshoe crabs, as well as others, including the extinct sea scorpions (pictured left). The common ancestor lived back in the Cambrian period.
Yale University's Peabody Museum of Natural History has put together a video that looks at the chelicerata evolutionary tree from a different perspective. They've used morphing technology to show the transformation of the ancestral Cambrian progenitor into each of the major sub-groups. Of course it's not perfect. For one thing, the ancestor must be an approximation based on the fossils of the time. Also, photographic morph isn't the most accurate depiction of how evolution works--especially when transitional fossils are sparse. Different body parts change at different rates and often go through stages that don't fit into the progressio of pictures in the morph.
Having said that, it's a very cool video. Check it out!