Biology for Survival

Abstract

The very acceptance of the word survival connotes the belief that extinction is possible. As individuals we expect to become extinct; as a group of organisms we hope to survive. At best calculations it is usually conceded that there must be living today at least a million species of animal life. Yet this great number is, perhaps, but a handful compared to the vast hordes that have lived and become extinct in all the past ages of the earth. The brief notations in the earth's own fossil dairy are interpreted to us by paleontologists as indicating that there have been eras in the past, some of them millions, of years in length, when certain groups were very abundant both in number of species and number of individuals. There was the age of mollusks, the age of great reptiles, the age of fishes. Thousands of species in these larger groups were abundant enough to leave many fossils but they are now extinct. How many more may have existed but have never been found? We do not know where life came from nor when it began. We do not even know if it ever began. When that statement is made to a group of students they always look up with a puzzled expression. They say that if life exists today it must have had a beginning; everything had to have a beginning. But when asked if it is not quite possible to think of life as continuing on down through the future for eternity, they agree. We have thought of this for most of our lives. If life can exist from the present to infinity in the future, why could it not have existed from the present to infinity in the past? Most persons struggle with this idea, but only because it is new to them. So we do not know where or when life began or if it began, but we do know that it has existed in myriad forms from ultramicroscopic viruses and phages to giant saurians and whales. We do know that many more forms have become extinct than have survived, and can assume that many forms now extant will become extinct. Are there reasons to believe that man will be different from the rest? Man is an organism, composed of cellular units, and chemical compounds like other organisms. Man is a mammal, a member of a special group of organisms. He has hair and milk glands, reproduces, rears his young, carries on body funetions, and dies like the others. Man is larger than most animals, but smaller than some. Man is stronger than most animals, but weaker than some. Man's life span is longer than most animals, but shorter than others. Man has many generalizations, but a few specializations. A horse has a highly specialized foot. Only one toe remains; bones have disappeared and the nail has become a hoof. These are good weapons of defense and offense and an excellent means of rapid transit over long distances. But a horse cannot play a piano or finger the strings of a violin, or paint a picture. Man cannot claw with the tiger, or bite with the wolf, or fly with the bird, or swim with the fish. He lacks the appropriate specializations to do this although he possesses the same basic structures. But he can make a sharp headed spear that will slay the tiger and the wolf; and he * Presented before the sectonal meetings of the National Association of Biology Teachers and Detroit Biology Club at Cranbrook Institute, Michigan, November 19, 1949.