As we have stated before, the theory of evolution proposes that some imaginary creatures that came out of the sea turned into reptiles, and that birds evolved from reptiles. According to the same scenario, reptiles are the ancestors not only of birds, but also of mammals. However, there are great differences between these two classes. Mammals are warm-blooded animals (this means they can generate their own heat and maintain it at a steady level), they give live birth, they suckle their young, and their bodies are covered in fur or hair. Reptiles, on the other hand, are cold-blooded (i.e., they cannot generate heat, and their body temperature changes according to the external temperature), they lay eggs, they do not suckle their young, and their bodies are covered in scales.

Given all these differences, then, how did a reptile start to regulate its body temperature and come by a perspiratory mechanism to allow it to maintain its body temperature? Is it possible that it replaced its scales with fur or hair and started to secrete milk? In order for the theory of evolution to explain the origin of mammals, it must first provide scientific answers to these questions.

Yet, when we look at evolutionist sources, we either find completely imaginary and unscientific scenarios, or else a profound silence. One of these scenarios is as follows:

Some of the reptiles in the colder regions began to develop a method of keeping their bodies warm. Their heat output increased when it was cold and their heat loss was cut down when scales became smaller and more pointed, and evolved into fur. Sweating was also an adaptation to regulate the body temperature, a device to cool the body when necessary by evaporation of water. But incidentally the young of these reptiles began to lick the sweat of the mother for nourishment. Certain sweat glands began to secrete a richer and richer secretion, which eventually became milk. Thus the young of these early mammals had a better start in life.147

The above quotation is nothing more than a figment of the imagination. Not only is such a fantastic scenario unsupported by the evidence, it is clearly impossible. It is quite irrational to claim that a living creature produces a highly complex nutrient such as milk by licking its mother's body sweat.

There is no difference between fossil mammals dozens of millions of years old in natural history museums and those living today. Furthermore, these fossils emerge suddenly, with no connection to species that had gone before.

The reason why such scenarios are put forward is the fact that there are huge differences between reptiles and mammals. One example of the structural barriers between reptiles and mammals is their jaw structure. Mammal jaws consist of only one mandibular bone containing the teeth. In reptiles, there are three little bones on both sides of the mandible. Another basic difference is that all mammals have three bones in their middle ear (hammer, anvil, and stirrup). Reptiles have but a single bone in the middle ear. Evolutionists claim that the reptile jaw and middle ear gradually evolved into the mammal jaw and ear. The question of how an ear with a single bone evolved into one with three bones, and how the sense of hearing kept on functioning in the meantime can never be explained. Not surprisingly, not one single fossil linking reptiles and mammals has been found. This is why the renowned evolutionist science writer Roger Lewin was forced to say, "The transition to the first mammal, ...is still an enigma."148

George Gaylord Simpson, one of the most important evolutionary authorities and a founder of the neo-Darwinist theory, makes the following comment regarding this perplexing difficulty for evolutionists:

The most puzzling event in the history of life on earth is the change from the Mesozoic, the Age of Reptiles, to the Age of Mammals. It is as if the curtain were rung down suddenly on the stage where all the leading roles were taken by reptiles, especially dinosaurs, in great numbers and bewildering variety, and rose again immediately to reveal the same setting but an entirely new cast, a cast in which the dinosaurs do not appear at all, other reptiles are supernumeraries, and all the leading parts are played by mammals of sorts barely hinted at in the preceding acts.149

Furthermore, when mammals suddenly made their appearance, they were already very different from each other. Such dissimilar animals as bats, horses, mice, and whales are all mammals, and they all emerged during the same geological period. Establishing an evolutionary relationship among them is impossible even by the broadest stretch of the imagination. The evolutionist zoologist R. Eric Lombard makes this point in an article that appeared in the leading journal Evolution:

Those searching for specific information useful in constructing phylogenies of mammalian taxa will be disappointed.150

In short, the origin of mammals, like that of other groups, fails to conform to the theory of evolution in any way. George Gaylord Simpson admitted that fact many years ago:

This is true of all thirty-two orders of mammals ... The earliest and most primitive known members of every order [of mammals] already have the basic ordinal characters, and in no case is an approximately continuous sequence from one order to another known. In most cases the break is so sharp and the gap so large that the origin of the order is speculative and much disputed ... This regular absence of transitional forms is not confined to mammals, but is an almost universal phenomenon, as has long been noted by paleontologists. It is true of almost all classes of animals, both vertebrate and invertebrate...it is true of the classes, and of the major animal phyla, and it is apparently also true of analogous categories of plants.151

147 George Gamow, Martynas Ycas, Mr. Tompkins Inside Himself, The Viking Press, New York, 1967, p. 149.
148 Roger Lewin, "Bones of Mammals, Ancestors Fleshed Out," Science, vol. 212, June 26, 1981, p. 1492. (emphasis added)
149 George Gaylord Simpson, Life Before Man, Time-Life Books, New York, 1972, p. 42. (emphasis added)
150 R. Eric Lombard, "Review of Evolutionary Principles of the Mammalian Middle Ear, Gerald Fleischer," Evolution, vol. 33, December 1979, p. 1230.
151 George G., Simpson, Tempo and Mode in Evolution, Columbia University Press, New York, 1944, pp. 105, 107.