Sea Spiders Aren't Spiders

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Sea spiders aren't spiders, according to an article in ScienceNOW 19 October 2005 and Nature, vol 437, p 20 October 2005. Sea spiders live on the sea floor where they eat seaweed and small invertebrates. They are believed to have evolved 490 million years ago and have been classified as spiders because they have eight legs and a pair of pincers, called chelifores at the front of their heads. The chelifores are believed to be modifications of the fangs of land dwelling spiders. Biologists at Harvard University have studied the brains developing embryos of sea spiders to find out where the chelifores get their nerve supply from. Land spider fang nerves come from the midbrain, but sea spider chelifore nerves come from the front part of the brain. According to ScienceNOW "This supports the theory that sea spiders belong to their own ancient lineage that predates the origin of all other modern arthropods." Max Telford, an evolutionary biologist at the University College London, UK commented that the study showed convincingly that sea spiders were "extraordinary living fossils".

Editorial Comment: Charles Darwin invented the term "living fossil" to describe any creature that has not changed since it first appeared in the geological record. Any creature that has appeared suddenly with a distinctive body plan that is unchanged for 490 million years certainly is an "extraordinary living fossil", but this also means the Sea Spider provides no evidence for evolution. This study is good evidence that sea spiders were created as distinct fully functional creatures and have multiplied after their kind ever since - just as Genesis describes all living creatures. (Ref. embryology, arachnids, classification)

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