Posted by anyman on Apr 01, 2002 at 19:18
The development of jaws was a critical event in vertebrate evolution, marking a transition to a predatory lifestyle, but how this innovation came about has been a mystery. In the embryos of jawed vertebrates (gnathostomes), the jaw cartilage develops from the mandibular arch, where none of the Hox patterning genes is expressed — but if the Hox genes are expressed artificially, jaw development is inhibited. The discovery that in the lamprey, a primitively jawless (agnathan) fish that is a sister group to the gnathostomes, a Hox gene is expressed in the mandibular arch of developing embryos suggests that loss of Hox expression from the mandibular arch of gnathostomes may have facilitated the evolution of jaws. (emp mine -- am)
 once again, there is a mystery about how evolution occured...in other words, that evolution happened is a fact but we have, or had until now, absolutely no idea how it happened
and we're still not sure...but maybe
 it was, once again, a loss of information that made it possible
isn't that interesting...
in observational science...we regularly find information being lost from various genomes
but we have yet to observe a single instance of brand new, absolutely novel, never before extant highly specific complex information arising from non-organic material
there are examples of lateral transfer ( borrowing ) of information from one genome to another...but...that information is already extant...it is not brand new, it is not absolutely novel, and it is not never before extant
we encounter the same problem for recombination of extant highly specific complex genetic information, etc...these mechanisms all require highly specific complex information that is by definition... already extant
therefore, for the darwinian paradigm to be valid, there must be some mechanism by which massive quantities of
highly specific complex information can arise...millions of times...and not only arise...but arise in the right place at the right time and in the right order before it can serve any useful biological function
unless one would now argue that all genetic information now contained in the myriad of genomes was already present in the protoorganism...even then you would have to demonstrate how it was dispersed and all just accidentally, by random chance luck without direction or purpose managed to coalesce into the known genomes (and the ever so many implied via the extinct fossil record) with the minimum fundamental systemic parts for every physiological system in the right place at the right time and in the right order...
no...you wouldn't argue that...
and a another thought here...
The development of jaws was a critical event in vertebrate evolution, marking a transition to a predatory lifestyle...
if "the development of jaws was [such] a critical event in vertebrate evolution, marking a transition to a predatory lifestyle"...then why are so many vertebrates with jaws NOT predatory
more lost info ----> evo or devo
- Re: mandibular evolution dogrock 02/4 03:36 (0)
- Re: mandibular evolution mara 01/4 23:06 (17)
- Re: mandibular evolution anyman 02/4 02:28 (8)
- Re: mandibular evolution mara 09/4 14:45 (0)
- Re: mandibular evolution Ben 02/4 19:04 (6)
- Re: mandibular evolution anyman 02/4 02:24 (0)
- Re: mandibular evolution DA Morgan 02/4 02:11 (6)
- Re: mandibular evolution y 01/4 20:58 (6)
- Re: mandibular evolution y 01/4 20:56 (0)
- Re: mandibular evolution Andy™ 01/4 20:27 (1)
- Re: mandibular evolution y 01/4 21:16 (0)
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