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Message: <blockquote data-quote="MANTI5" data-source="post: 7665546" data-attributes="member: 627711">"Trying to bridge the gap between amphibian and reptile poses other serious problems. A most difficult one is the origin of the shelled egg. Creatures prior to reptiles laid their soft, jellylike eggs in water, where the eggs were fertilized externally. Reptiles are land based and lay their eggs on land, but the developing embryos inside them must still be in a watery environment. The shelled egg was the answer. But it also required a major change in the process of fertilization: It called for internal fertilization, before the egg is surrounded by a shell. To accomplish this involved new ****** organs, new mating procedures and new instincts—all of which constitute a vast gulf between amphibian and reptile.Enclosing the egg in a shell made necessary further remarkable changes in order to make possible the development of a reptile and, finally, its release from the shell. For example, within the shell there is the need for various membranes and sacs, such as the amnion. This holds in the fluid in which the embryo grows. The Reptiles describes another membrane called the allantois: “The allantois receives and stores embryonic waste, serving as a sort of bladder. It also has blood vessels that pick up oxygen that passes through the shell and conduct it to the embryo.”Evolution has not accounted for other complex differences involved. Embryos in fish and amphibian eggs release their wastes in the surrounding water as soluble urea. But urea within the shelled eggs of reptiles would kill the embryos. So, in the shelled egg a major chemical change is made: The wastes, insoluble uric acid, are stored within the allantois membrane. Consider this also: The egg yolk is food for the growing reptile embryo, enabling it to develop fully before emerging from the shell—unlike amphibians, which do not hatch in the adult form. And to get out of the shell, the embryo is distinctive in having an egg tooth, to help it break out of its prison."Much more is needed to bridge the gap between amphibian and reptile, but these examples show that undirected chance just cannot account for all the many complex changes required to bridge that wide gulf. No wonder evolutionist Archie Carr lamented: “One of the frustrating features of the fossil record of vertebrate history is that it shows so little about the evolution of reptiles during their earliest days, when the shelled egg was developing.”</blockquote>

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