(January 23, 2014 at 3:45 pm)Pickup_shonuff Wrote:(January 23, 2014 at 3:38 pm)Mister Agenda Wrote: It was quite a mystery in the late 1800s when the Burgess Shale fossils were first discovered, but more than a century of new finds make it clear that the 'explosion' happened over the course of at least 30 million years. A lot can happen in 30 million years. There's nothing here that's a problem for the theory of evolution.
I know it has something to do with regulatory genes but how come new body plans have not come about since the Cambrian explosion? What environmental conditions account for the sudden appearance and diversity of skeletal body plans at ONLY that time? Sure there may have been more oxygen in the atmosphere but how come fundamental body plans haven't diversified since then as we might expect?
First, you would have to establish that we would expect them to. What new body plans should we have expected to appear that are missing?
Natural selection is conservative, it preserves what works for as long as it works better than the alternatives.
