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mikeynov said:Two questions for you (being serious, not trying to pick a fight)
1) What WOULD qualify as evidence to establish common ancestry between any two organisms in your mind? Meaning, supposing the idea were true for a second (hypothetically), what would you expect to see with common ancestry? As such, how does this differ from what we do see? I mean this in any terms you'd like - fossils, DNA, comparative anatomy, whatever.
Frankly, I would expect a comprehensive transitional:
The oldest fossil whales are often grouped together, largely for convenience, in a taxon known as the archaeocetes. Archaeocetes show several features that modern whales lack. Their teeth, like those of most land mammals, still show differentiation into several types. (Modern whales either lack teeth, or have teeth that are all virtually identical in shape and size). Archaeocetes also had nostrils near the tip of the nose, like land mammals, rather than a blowhole on the top of the head. Some retained substantial hind limbs that would have been visible outside the animal's body; in the earliest archaeocetes, these limbs and the pelvis were attached to the vertebrae by a sacral joint, but in later ones the limbs and pelvis were not attached to the rest of the skeleton.
http://www.ucmp.berkeley.edu/mammal/cetacea/cetacean.html
Homo habilis
The type specimen was a mandible, with associated postcranial bones, and a fragmentary cranial vault; Olduvai Hominid 7 (OH 7). They based their placement of OH 7 in Homo primarily on brain expansion. Until then, an arbitrary lower limit had been set between 700cc and 800cc as the cutoff for the genus Homo. With an estimated cranial capacity of 680cc, Leakey and his colleagues chose to lower this number to 600cc. While calling attention to anatomical differences between OH 7 and Australopithecus, they chose a behavior- the ability to make stone tools-to help place OH 7 in Homo. This point relied on stone tools found in the same geologic horizon as the fossils.
http://www.mnh.si.edu/anthro/humanorigins/ha/hab.html
The Homo habilis Debate
One debate in paleoanthropology today is whether or not ER 1470, and several other fossils previously identified as H. habilis, should be grouped into a new species, Homo rudolfensis. This classification would acknowledge that ER 1470 and the other members of Homo rudolfensis differ more from Homo habilis, sensu stricto ("in the strict sense," meaning: as originally defined), than could possibly be accounted for by variation within a population or between sexes. This would place two species of the genus Homo in Africa during the same time period in addition to two members of the genus Paranthropus, and, possibly, late surviving members of the species Australopithecus africanus. Far more complicated than the original neat, linear model.
http://www.mnh.si.edu/anthro/humanorigins/ha/habdebate.html
Homo rudolfensis
The species Homo rudolfensis was originally proposed in 1986 by V. P. Alexeev for the specimen to the left, KNM ER 1470. Originally thought to be a member of the species Homo habilis, much debate surrounded the fossil and its species assignment. It was thought that 2 million years ago there existed a single species in the genus Homo, and this species evolved in a linear fashion into modern humans.
But the differences in this skull, when compared to other habilines, are too pronounced, leading to the formulation of the species Homo rudolfensis, contemporary with Homo habilis.
Homo erectus
The species Homo erectus is thought to have diverged from Homo ergaster populations roughly 1.6 million years ago, and then spread into Asia. It was believed that Homo erectus disappeared as other populations of archaic Homo evolved roughly 400,000 years ago. Evidently, this is not the case. Recent studies into the complicated stratigraphy of the Java Homo erectus sites have revealed some surprising information. Researchers have dated the deposits thought to contain the fossils of H. erectus near the Solo River in Java to only 50,000 years ago. This would mean that at least one population of Homo erectus in Java was a contemporary of modern humans
http://www.mnh.si.edu/anthro/humanorigins/ha/erec.html
The reason evolutionists are confident that mesonychids gave rise to archaeocetes, despite the inability to identify any species in the actual lineage, is that known mesonychids and archaeocetes have some similarities. These similarities, however, are not sufficient to make the case for ancestry, especially in light of the vast differences. The subjective nature of such comparisons is evident from the fact so many groups of mammals and even reptiles have been suggested as ancestral to whales
It is important to understand that, in calling these creatures a series of transitional fossils, the evolutionist does not mean that they form an actual lineage of ancestors and descendants. On the contrary, they readily acknowledge that these archaeocetes cannot be strung in procession from ancestor to descendant in a scala naturae.
http://www.trueorigin.org/whales.asp
The generally accepted order of the archaeocete species, in terms of both morphological (primitive to advanced) and stratigraphical (lower/older to higher/younger) criteria, is Pakicetus, Ambulocetus, Rodhocetus, Indocetus, Protocetus, and Basilosaurus (see note 16). One problem for this tidy picture is that the stratigraphical relationships of most of these fossils are uncertain
http://www.trueorigin.org/whales.asp#b22
2) If you have real doubt as to the capacity for 'microevolutionary' changes amounting to speciative events, how do you respond to empirical examples of such speciative events? You did acknowledge ring species in another thread, yes? There are examples of this in the literature, and it wouldn't be hard pointing you to many other examples of speciation, if you're interested.
The microevolutionary changes do not accumulate, thats the whole problem with this supposed theory. They revert back to the original condition because the genetic blueprint makes it so. I am sure you all have seen the peppered moths of england and the finches Darwin described in Origin of Species. Does it mean nothing to you that both of those populations have reverted back to their original form?
Now as to ring species, I know that there are times when speciation occures and that there are times when related groups are not capable of producing fertlile offspring. This is not a problem for creationism, nature was allways intended to become diverse and complicated. Still none of you have offered a definition of species, which is curious, since it is the whole point of the thread.
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