EVIDENCE OF COMMON ANCESTORY AND GAIA PROGRAMMING?
"... This interaction sometimes results in such a balanced steady state that some authors have proposed a Gaia hypothesis, according to which the Earth's inanimate and living worlds together form a well-balanced and programmed system."
"... seven competing theories for the origin of life have been proposed. Although no fully satisfactory theory has yet emerged, the problem no longer seems as formidable as at the beginning of the twentieth century. One is justified to claim that there are now a number of feasible scenarios of how life could have originated from inanimate matter. To understand these various theories requires a good deal of technical knowledge of biochemistry. To avoid burdening this volume with such detail, I refer the reader to the special literature dealing with the origin of life (Schopf 1999; Brack 1999; Oparin 1938; Zubbay 2000)".
"...the same reason why all terrestrial vertebrates (tetrapods) develop gill arches at a certain stage in their ontogeny. These gill-like structures are never used for breathing, but instead are drastically restructured during the later ontogeny and give rise to many structures in the neck region of reptiles, birds, and mammals. The evident explanation is that the genetic developmental program has no way of eliminating the ancestral stages of development and is forced to modify them during the subsequent steps of development in order to make them suitable for the new life-form of the organism. The anlage of the ancestral organ now serves as a somatic program for the ensuing development of the restructured organ (Mayr 1994). What is recapitulated are always particular structures, but never the whole adult form of the ancestor.
Vestigial Structures. Many organisms have structures that are not fully functional or not functional at all. The human caecal appendix is an example (sometimes has to be removed from acute appendicitis) and so are the teeth in baleen whale embryos and the eyes in many cave animals. Such vestigial structures are the remnants of structures that had been fully functional in their ancestors but are now ready reduced owing to a change in niche utilization. When these structures lose their function owing to a shift in lifestyle, they are no longer protected by natural selection and are gradually deconstructed. They are informative by showing the previous course of evolution.
These three phenomena: embryonic similarities, recapitulation, and vestigial structures raise insurmountable difficulties for a creationist explanation, but are fully compatible with an evolutionary explanation based on common descent, variation, and selection."
"Biogeography. Evolution also helped to explain another great puzzle of biology, namely, the reasons for the geographic distribution of animals and plants. Why are the faunas of Europe and North America on both sides of the North Atlantic so relatively similar, whereas those of Africa and South America on both sides of the South Atlantic are so very different? Why is the fauna of Australia so strikingly different from that of all other continents?
Why are there normally no mammals on oceanic islands? Could these seemingly capricious patterns of distribution be explained as the product of creation? Not easily. Darwin, however, showed that the present distribution of animals and plants is due to the history of their dispersal from their original points of origin. The longer that two continents were isolated from each other, the more different their biota became."
... the reasons for the similarity of the fauna of Europe and of North America were not fully understood until it was discovered that in the early Tertiary (40 million years ago) there was a broad land connection across the north Atlantic between the two now-separated continents. This permitted an active faunal exchange. By contrast, Africa and South America were separated by continental drift 80 million years ago and their biota diverged greatly during their long isolation. Again and again, puzzling distribution patterns can be explained as the result of common descent and sometimes subsequent extinction. Thus evolution continues to provide the answer to many previously puzzling observations."
For a creationist there is no rational explanation for distributional irregularities, but they are completely compatible with a historical evolutionary explanation."
... "different kinds of molecules have different rates of evolutionary change. Some change very rapidly, like the fibrinopeptides, and others change very slowly, like the histones. Even though the lineages of man and chimpanzee separated at least 6 million years ago, the highly complex molecules of the hemoglobins of these two species are still virtually identical. What is gratifying is the fact that when a phylogeny based on morphological or behavioral characteristics is established, it is usually found to be essentially the same as a phylogeny based exclusively on molecular characteristics. The extremely close relationship of man to the chimpanzee and to the other anthropoid apes is as convincingly documented by molecular as by structural characters."
Taken from: Ernst Mayr, What Evolution Is, 2001