You know, if you have questions about science, there are many people who can help - but this has nothing to do with religion.
Claim CC216.1:
There are gaps between land mammals and whales.
Source:
Gish, Duane T., 1994. When is a whale a whale? Impact 250 (Apr.). http://www.icr.org/index.php?module=articles&action=view&ID=379
Response:
1. The transitional sequence from a land mammal to whales is quite robust. See Babinski (2003) or Zimmer (1998) for pictures of some of these.
1. Pakicetus inachus: latest Early Eocene (Gingerich et al. 1983; Thewissen and Hussain 1993).
2. Ambulocetus natans: Early to Middle Eocene, above Pakicetus. It had short front limbs and hind legs adapted for swimming; undulating its spine up and down helped its swimming. It apparently could walk on land as well as swim (Thewissen et al. 1994).
3. Indocetus ramani: earliest Middle Eocene (Gingerich et al. 1993).
4. Dorudon: the dominant cetacean of the late Eocene. Their tiny hind limbs were not involved in locomotion.
5. Basilosaurus: middle Eocene and younger. A fully aquatic whale with structurally complete legs (Gingerich et al. 1990).
6. an early baleen whale with its blowhole far forward and some structural features found in land animals but not later whales (Stricherz 1998).
The whale's closest living relative is the hippopotamus. A fossil group known as anthracotheres links hippos with whales (Boisserie et al. 2005). The common ancestor of whales and hippos likely was a primitive artiodactyl (cloven-hoofed mammal); ankle bones from the primitive whales Artiocetus and Rodhocetus show distinctive artiodactyl traits (Gingerich et al. 2001).
Links:
Babinski, E. T., 2003. Cetacean evolution (whales, dolphins, porpoises) http://www.edwardtbabinski.us/babinski/whale_evolution.html
Sutera, Raymond, 2001. The origin of whales and the power of independent evidence. Reports of the National Center for Science Education 20(5): 33-41. http://www.talkorigins.org/features/whales/
References:
1. Boisserie, Jean-Renaud, Fabrice Lihoreau and Michel Brunet. 2005. The position of Hippopotamidae within Cetartiodactyla. Proceedings of the National Academy of Science USA 102(5): 1537-1541.
2. Gingerich, P. D. et al., 1983. Origin of whales in epicontinental remnant seas: New evidence from the Early Eocene of Pakistan. Science 220: 403-406.
3. Gingerich, P. D., B. H. Smith, and E. L. Simons, 1990. Hind limb of Eocene Basilosaurus: Evidence of feet in whales. Science 249: 154-157.
4. Gingerich, P. D. et al., 1993. Partial skeletons of Indocetus ramani [Mammalia, Cetacea] from the Lower Middle Eocene Domanda Shale in the Sulaiman Range of Punjab [Pakistan]. Contributions from the Museum of Paleontology of the University of Michigan 28: 393-416.
5. Gingerich, P. D. et al., 1994. New whale from the Eocene of Pakistan and the origin of cetacean swimming. Nature 368: 844-847.
6. Gingerich, P. D. et al. 2001. Origin of whales from early artiodactyls: Hands and feet of Eocene Protocetidae from Pakistan. Science 293: 2239-2242. See also: Rose, K. D. 2001. The ancestry of whales. Science 293: 2216-2217.
7. Thewissen, J. G. M. and S. T. Hussain, 1993. Origin of underwater hearing in whales. Nature 361: 444-445.
8. Thewissen, J. G. M., S. T. Hussain and M. Arif, 1994. Fossil evidence for the origin of aquatic locomotion in archaeocete whales. Science 263: 210-212. See also Berta, A., 1994. What is a whale? Science 263: 180-181.
9. Stricherz, Vince, 1998 (10 Oct.). Burke displays fossil of toothless whale. http://depts.washington.edu/uweek/archives/1998.10.OCT_29/_article2.html See also http://more.abcnews.go.com/sections/science/DailyNews/baleen980916.html
Further Reading:
Gould, S. J. 1995. Hooking leviathan by its past. In: Dinosaur in a Haystack. New York: Harmony Books, pp. 359-376.
Pojeta, John Jr. and Dale A. Springer. 2001. Evolution and the Fossil Record, American Geological Institute, Alexandria, VA. http://www.agiweb.org/news/spot_06apr01_evolutionbk.htm , http://www.agiweb.org/news/evolution.pdf .
Thewissen, J. G. M. (ed.). 1998. The Emergence of Whales: evolutionary patterns in the origin of Cetacea. New York: Plenum. (technical)
Thewissen, J. G. M., S. I. Madar, and S. T. Hussain. 1998. Whale ankles and evolutionary relationships. Nature 395: 452. See also Wong, K., 1999 (Jan.). Cetacean creation. Scientific American 280(1): 26,30.
Thewissen, J. G. M. and E. M. Williams. 2002. The early radiations of Cetacea (Mammalia): Evolutionary pattern and developmental correlations. Annual Review of Ecology and Systematics 33: 73-90. (technical)
Zimmer, Carl. 1995. Back to the sea. Discover 16(1) (Jan.): 82-84.
Zimmer, Carl. 1998. At the Water's Edge. New York: Touchstone, ch. 6-10.
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Claim CC200.1:
Given all the species that exist and have existed, there should be billions of transitional fossils in the fossil record; we should have found tens of thousands at least.
Source:
Gish, Duane T., 1994. When is a whale a whale? Impact 250 (Apr.). http://www.icr.org/index.php?module=articles&action=view&ID=379
Response:
1. Some important factors prevent the formation of fossils from being common:
* Fossilization itself is not a particularly common event. It requires conditions that preserve the fossil before it becomes scavenged or decayed. Such conditions are common only in a very few habitats, such as river deltas, peat bogs, and tar pits. Organisms that do not live in or near these habitats will be preserved only rarely.
* Many types of animals are fragile and do not preserve well.
* Many species have small ranges. Their chance of fossilization will be proportionally small.
* The evolution of new species probably is fairly rapid in geological terms, so the transitions between species will be uncommon.
Passenger pigeons, once numbered in the billions, went extinct less than 200 years ago. How many passenger pigeon fossils can you find? If they are hard to find, why should we expect to find fossils that are likely from smaller populations and have been subject to millions of years of potential erosion?
2. Other processes destroy fossils. Erosion (and/or lack of deposition in the first place) often destroys hundreds of millions of years or more of the geological record, so the geological record at any place usually has long gaps. Fossils can also be destroyed by heat or pressure when buried deep underground.
3. As rare as fossils are, fossil discovery is still rarer. For the most part, we find only fossils that have been exposed by erosion, and only if the exposure is recent enough that the fossils themselves do not erode.
As climates change, species will move, so we cannot expect a transition to occur all at one spot. Fossils often must be collected from all over a continent to find the transitions.
Only Europe and North America have been well explored for fossils because that is where most of the paleontologists lived. Furthermore, regional politics interfere with collecting fossils. Some fabulous fossils have been found in China only recently because before then the politics prevented most paleontology there.
4. The shortage is not just in fossils but in paleontologists and taxonomists. Preparing and analyzing the material for just one lineage can take a decade of work. There are likely hundreds of transitional fossils sitting in museum drawers, unknown because nobody knowledgeable has examined them.
5. Description of fossils is often limited to professional literature and does not get popularized. This is especially true of marine microfossils, which have the best record.
6. If fossilization were so prevalent and young-earth creationism were true, we should find indications in the fossil record of animals migrating from the Ark to other continents.
Links:
Hunt, Kathleen. 1997. Transitional vertebrate fossils FAQ, part 1A. http://www.talkorigins.org/faqs/faq-transitional/part1a.html#gaps
Further Reading:
Kidwell, S. M. and S. M. Holland. 2002. The quality of the fossil record: Implications for evolutionary analyses. Annual Review of Ecology and Systematics 33: 561-588. (technical)