Real Life, some of my thoughts about the article, I will , of course play off your post for discussions sake.
Quote:a particular feature began and completed it's development-- not slowly as is generally pictured, but quite rapidly. A whole can of worms is open here since no one can seem to agree if evolution takes a long time or not.
Not to be flippant but evolution takes as long as is needed, no more, cause once a "Baldwin model" kicks in the genotype is aligned to strengthen that trait.Remember, IMHO , most evolution is adaptive , and there were plenty of events in the past to either adapt to, or die.
Quote:Further, it is hypothesized that this same feature evolved numerous times independently of each other in groups of similar fish in scattered locations. So that the end result is that similar groups of fish all coincidentally have the same feature and 'evolution is the reason why
This is evidence based logic. In most cases, we have so many incidental fossils to deal with that it within the bauplan at interim times (stratigraphically) that "evolution seems to be the best model" <As Ive said in a number of previous posts and noone argued, "There is ample evidence that convergent features occur in many rootstocks and divergent daughter populations (feathers on dinosaurs,"Sabre tootness etc)"
I think Timber gave a consensus about genes being economic and multiple in their expressions. Think about the consequences of that very point. The Creationists have been crying"not enough time for evolution" yet they fail to remember that the same Hox gene that multi expresses for many features thoracic is known from genomic studies of everything from lamreys to muskrats.Once a gene is useable and is set , it becomes part of the "baggage" that the organism carries throughout its future progeny. Also, his comment about genetic diversity is part of a thread that Ros had started awhile back.
As far as "a fish is still a fish", you, metaphorically, need to "put your fingers into the nailholes" before you will be convinced.
The fossil collections of major U's and big museums have thousands and maybe even millions more "intermediates" than they plant out for the kiddies to see on display. The lesson we learned from reading the fossil record and applying genome structures back to root taxa that are alive today, provides some pretty hard evidence to an open minded person.
Im used to the reasoning that Creationists had used to implant doubt in their audiences regarding evolution of higher taxa. Theyve said that there "are gaps unaccounted for by science" So, in the last 20 or so yeqrs , most of the remaining gaps have been filled in and the bush of evolution has been filled out. So when we parade this evidence out, the Creationists say, "well now there are 2 gaps"
Im aware that we wont agree that intermediate fossils are meaningful.Thats probably because I use their signs in stratigraphic analyses , and when were stumped, we usually send the specimen to a colleague who can pinpoint it closely to the unit or type-unit that we are seeking.
I look at fossils as a basic tool in investigations. I usually have to acquire money from my clients to devvelop prospect areas and , in order to do a believable job, I need to present compelling evidence. Id call that a "wallet test" of whether descent with modifications is valuable.
We are now on the edge of seeing when the bony fishes made their first attempts at land living (and to deduce an environmental cause for them to leave their perfectly safe habitat and go out on land and develop into amphibians and reptiles). Your article about stickelbacks is useful, since a heretofore genetic mystery, as to which came first amphibians , or reptiles from fish.
The easy observation has been that the major taxa, as they began to appear in the Paleozoic, usually follwed some environmental cataclism or stratigraphic disruption .The remainders did not lose their basic genetic code, they only lost a large part of their diversity so the remainders provide the rootstock to go in a direction that the resultant environment readily supports (until the next cataclysm comes along)
I think that the best we can do is let the article sink in. Im happy with its fundamental reporting. I have some disagreements with the reporters misunderstandings and conclusions , but seeing as science reporting is done by "journalists first" I dont object strongly to them. All in all the article supports the fact that the genome is economic (once a gene functioning group is tripped on, the entire sequence of genes stays put and does not get excised in future evolutionary descendants--that saves time and money), genetic diversity is the root of most all evolution (in response to adaptive pressure), Multiple genes can have single effects and single genes , multiple effects,: Phenotypic variation fits a small numbber of basic body plans.
Quote:An alternate position would point out that the fish very likely could have been given various genetic variations to produce features as needed, as part of their initial design, so that perhaps no 'change' has really 'happened' at all.
. How do you propose to evidence this ? You would have to (by your own rules) rule out intermediate species because if they display too much non "fishness" they cant be valid data. Im concerned that youve painted yourself into a corner here.
