Book review of Nature\'s I.Q. (Evolution)

by David Turell , Saturday, September 12, 2009, 01:39 (5350 days ago) @ xeno6696

Here, critique these:
> 
> http://talkorigins.org/indexcc/CC/CC300.html
> 
> http://talkorigins.org/indexcc/CC/CC301.html -Makes no point. Not worth anything.
 
> (Sorry to use talkorigins but I know quite a few biologists and paleontologists worked to put it together.)-Please don't ask me again to refute incorrect material:
Claim CC300:
Complex life forms appear suddenly in the Cambrian explosion, with no ancestral fossils. 
Source:
Morris, Henry M. 1985. Scientific Creationism. Green Forest, AR: Master Books, pp. 80-81. 
Watchtower Bible and Tract Society. 1985. Life--How Did It Get Here? Brooklyn, NY, pp. 60-62. 
Response:
1.	The Cambrian explosion was the seemingly sudden appearance of a variety of complex animals about 540 million years ago (Mya), but it was not the origin of complex life. Evidence of multicellular life from about 590 and 560 Mya appears in the Doushantuo Formation in China (Chen et al. 2000, 2004), and diverse fossil forms occurred before 555 Mya (Martin et al. 2000).
 
DJT: Multicellular does not mean complex like in the Cambrian. Edicaran are branching fronds. Bilatarians were digesting sacks with mouth and anal opening. Complex? Hardly like Cambrian.-2.	Testate amoebae are known from about 750 Mya (Porter and Knoll 2000). There are tracelike fossils more than 1,200 Mya in the Stirling Range Formation of Australia (Rasmussen et al. 2002). Eukaryotes (which have relatively complex cells) may have arisen 2,700 Mya, according to fossil chemical evidence (Brocks et al. 1999). 
DJT: Eukaryotes 'may' have arisen from chemical evidence. A nice stretch.
3.	Stromatolites show evidence of microbial life 3,430 Mya (Allwood et al. 2006). Fossil microorganisms may have been found from 3,465 Mya (Schopf 1993). There is isotopic evidence of sulfur-reducing bacteria from 3,470 Mya (Shen et al. 2001) and possible evidence of microbial etching of volcanic glass from 3,480 Mya (Furnes et al. 2004). 
DJT: 2 & 3 are all about one celled forms; Stromatolites are large masses of bacteria!-4.	There are transitional fossils within the Cambrian explosion fossils. For example, there are lobopods (basically worms with legs) which are intermediate between arthropods and worms (Conway Morris 1998). 
DJT: Is this fact on point? I don't see it.
5.	Only some phyla appear in the Cambrian explosion. In particular, all plants postdate the Cambrian, and flowering plants, by far the dominant form of land life today, only appeared about 140 Mya (Brown 1999). 
Even among animals, not all types appear in the Cambrian. Cnidarians, sponges, and probably other phyla appeared before the Cambrian. Molecular evidence shows that at least six animal phyla are Precambrian (Wang et al. 1999). Bryozoans appear first in the Ordovician. Many other soft-bodied phyla do not appear in the fossil record until much later. Although many new animal forms appeared during the Cambrian, not all did. According to one reference (Collins 1994), eleven of thirty-two metazoan phyla appear during the Cambrian, one appears Precambrian, eight after the Cambrian, and twelve have no fossil record. The fish that appeared in the Cambrian was unlike any fish alive today.-DJT: 36 out of 37 ANIMAL phyla appeared in the Cambrian. All the fish found so far, there are 3, relate to current species. One is identified as a hagfish.
 
6.	The length of the Cambrian explosion is ambiguous and uncertain, but five to ten million years is a reasonable estimate; some say the explosion spans forty million years or more, starting about 553 million years ago. Even the shortest estimate of five million years is hardly sudden. 
DJT: No point to this. Proves nothing.-7.	There are some plausible explanations for why diversification may have been relatively sudden: 
·	The evolution of active predators in the late Precambrian likely spurred the coevolution of hard parts on other animals.
 
DJT: there is no evidence of this-·	Early complex animals may have been nearly microscopic. Apparent fossil animals smaller than 0.2 mm have been found in the Doushantuo Formation, China, forty to fifty-five million years before the Cambrian (Chen et al. 2004). Much of the early evolution could have simply been too small to see. -DJT: How come we can find ancient bacteria (one cell) but not microscopic complex animals. Ridiculous!-·	The earth was just coming out of a global ice age at the beginning of the Cambrian (Hoffman 1998; Kerr 2000). 
·	DJT: True-·	A "snowball earth" before the Cambrian explosion may have hindered development of complexity or kept populations down so that fossils would be too rare to expect to find today. The more favorable environment after the snowball earth would have opened new niches for life to evolve into. -·	DJT: My main objection: Does not explain the huge jump in complexity, just a time delay.-·	Hox genes, which control much of an animal's basic body plan, were likely first evolving around that time.-·	 DJT: 'Likely' is a wonderful weasel word-·	Atmospheric oxygen may have increased at the start of the Cambrian (Canfield and Teske 1996; Logan et al. 1995; Thomas 1997).
 
·	DJT: it did-
DJT:Both 8 & 9 beside the major point, the rapid jump in complexity.