Temporal Patterns in 'Living Fossils'
Type of Submission
Poster
Campus Venue
Dixon Ministry Center, Alumni Hall
Location
Cedarville, OH
Start Date
4-10-2013 1:00 PM
End Date
4-10-2013 5:00 PM
Creative Commons License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 3.0 License.
Apr 10th, 1:00 PM
Apr 10th, 5:00 PM
Temporal Patterns in 'Living Fossils'
Cedarville, OH
Comments
Abstract:
"Living fossils" are taxa which are living today and can be found in the ancient rock record. Well-known examples include the ginkgo tree (Ginkgo, 252-0 Ma), the coast redwood (Sequoia, 151-0 Ma), horsetails (Equisetum, 360-0 Ma), a brachiopod (Lingula, 488-0 Ma), an annelid worm (Spirobls, 488-0 Ma), and a mussel (Mytilus, 418-0 Ma). Many living genera have morphologically close sister taxa including the coelacanth fish (Latimeria) with Coelacanthus (318-247 Ma) and the horseshoe crab (Limulus) with Limuloides (419-416 Ma). A recent query of the Paleobiology Database (pbdb.org) was completed to find how many living fossil genera have been reported: 99 were fluid from the Paleozoic, 548 from the Mesozoic and 3,582 from the Cenozoic, for a total of 4,229. The database is continually being updated, so this Is surely an underestimate. The data were graphed using 10 Ma bins. The graph shows a spike In the number of genera at the K-T boundary; a time which corresponds to the transition from Flood to post-Flood rocks, about 4,300 years ago. From an old earth/evolutionary perspective "living fossils" are an unexpected problem. Evolution demands change over time, but some genera remain unchanged (maintain stasis) for tens or hundreds of millions of years. Furthermore, why are the numbers of living fossil taxa "flat" in Paleozoic and Mesozoic tines with a sudden spike during Cenozoic times? A Creation model might answer this observation as a result of rapid diversification of organisms following the Flood. Relatively few genera that were alive before the Flood were able to survive, morphologically unchanged. Rapid diversification may have been due to post-Flood climate changes or the opportunity to fill new niches in the empty post-Flood world. The biblical "kind" Is most commonly thought to be at the taxonomic level of the family; so when similar work is completed at this level, a more even distribution is expected through time.