MikeFerrara:
I certainly do see a trend. You don't offer proof. You offer what you accept as proof. I say, a fossil of a funny looking fish is proof that there were funny looking fish and you say it's proof that some fish evolved into mamals.
Mike, the problem is that you need to know what it is youre looking at. If all you see is a funny-looking fish, then you need to learn a lot more anatomy before you make fun of that which you do not yet understand. Paleontologists look at more than the gross morphology of the funny-looking fish. There are entire phylogenies that have been constructed by just looking at the pectoral fins, or the vertebrae, or the eye orbit, or the gill arches, or the baso-cranial circulation. Then experts have compared these phylogenies and dealt with discrepancies using the best evidence available. Thats how it was done before electrophoresis, immunological distance analysis and gene sequencing were available.
MikeFerrara:
How many generations must have existed in that transition from fish to mamal? How many are represented in the fossilt record. It seems to me that they are claiming to understand the nature of a chain that has almost countless links because they have what they think are a very few of those links. Then we have the obvious holes n the fossil record as illustrated by fish that they believed extinct for 65 million years or so (gone from the fossil record?) and then shows up alive and well.
Millions of generations. But when you look at the details of the component parts, the changes are rather clear. Finding relic populations of a fish species for which there has been no record for 65 million years, is not at all surprising to me and does not case any doubt on evolution.
MikeFerrara:
DNA...now here's proof for you. Where is the surprise that all life shows some DNA similarities? Where the sirprise in the fact that animals that are different show differences in DNA? But then they try to use the DNA differences to indirectly measure the time since splitting from a common ancestor...the existance of which is assumed rather than proven by DNA. To make matters worse they calibrate the time inference based on what? The fossil record. ok so now they add short term change data from bacteria and insects. The problem is that data points over such a short time aren't suficient to calibrate such a measurement over such a long time. The fossil record seems to offer far too few data points over the whole range to be valid. Assumptions as to linierity? curve fitting? Backed by data? How about a good old fashioned guage R&R. We engineers don't even accept the output of a mic or a simple weight scale without that much. So the problem is two pronged...the calibration of the time inference and the lack of direct evidence that the event, from which they are measuring time lapsed, ever happened in the first place.
Forget for a minute the idea of relating DNA change to time-scale, to me thats the least important thing anyway. There are many ways of analyzing DNA, indirect methods such as electrophoreses where you look at the proteins DNA produces or immunological distance studies where you prepare species specific anti-sera and them use the anti-sera to see how similar two other species are, and direct methods such as gene sequencing. The interesting thing is the consistency of results. All of these other techniques, which can be use to evolutionary trees that are time independent (they just describe who begat whom, so to speak), yield remarkably similar results, just as independent analysis of specified body parts has yielded remarkable similar results. An the clincher is that the all these independent methods: hard part analysis or many different specific structures, protein analysis, immunological distance analysis and gene sequencing yield evolutionary trees that are substantively the same. The evolutionary relationships have been confirmed so many different ways that the gross items are no longer even up for debate, and the fine items that have been carefully and exhaustively studied (e.g., primates) are also clearly defined.
MikeFerrara:
I saw something cute that seems to illustrate it well.
Frog(t) = prince at t = instantaneous = fairytale
Frog(t) = prince at t = a very long time = science
Cute, like a pre-teen beauty queen, and just as fatuous.