Most of us have seen movies or read books that portray times in Earth's history when life forms were much larger in size than in today's world. It was not just certain dinosaurs that were large. We find fossil remains of things that we are familiar with that indicate that even insects grew to incredible sizes in the past. There are wonderfully preserved fossil remains of a dragon fly called Meganeura which was the size of a modern day hawk. Ants a foot long and centipedes that were as big as two feet in length show up in the fossil record. There are also fossils of mammals that were massive in size, far beyond any land mammal living today, with a sloth that stood forty-five feet tall and weighed as much as fifteen tons.
A major key to these huge sizes seems to be the amount of oxygen that was in the atmosphere at the time these animals lived. New laboratory techniques in nuclear chemistry are giving us accurate methods of determining the oxygen content of the atmosphere in the past, and ice cores and tree rings have provided ways of confirming the measurements. We now have a fairly complete story of how the earth's atmosphere has changed over the centuries. Studies show that the earth's atmosphere has had oxygen content as high as 35 percent in the past (as opposed to 21 percent today.) This higher oxygen content would have some negative consequences, with fires burning much hotter and faster, corrosion happening faster, etc. It's impact on some living things however, would be very positive.
Laboratory experiments have also shown us how oxygen content affects the size of living things. Insects do not breathe. Oxygen diffuses into the animal's bloodstream directly from the atmosphere, so there are no lungs present to get oxygen into the insect's system. Dr. Robert Berner at Yale has shown that a 35 percent level of oxygen in the atmosphere would increase the diffusion rate of oxygen into an insect's bloodstream by as much as 67 percent. Arizona State University researchers have shown that body size varies directly with oxygen concentration. Experiments with fruitflies and mealworms consistently show high growth rates with increased oxygen concentrations. Studies done on alligators have shown that variations in egg development and growth in alligators also are in direct proportion to the oxygen concentration of the atmosphere they are breathing. Dr. Paul Falkowski of Rutgers has verified that similar data applies to mammals. Falkowski says "Pound for pound, mammals typically need three times as much oxygen as reptiles do," so conditions that would support reptiles might not be capable of supporting mammals.
All of this is very helpful in understanding a variety of issues that relates to the Bible as well as to the evolution/creation controversy. It is increasingly obvious that dinosaurs and humans could not survive together on this planet. Not only can mammals not tolerate the high temperatures and low oxygen content that was present on the earth in the past, but domestication of reptiles is impossible and competition for food and living space would be most difficult.
The Bible does not describe dinosaurs to us, and no Hebrew word in Genesis 1 could legitimately be interpreted to mean dinosaurs. The animal described in Job 40:15-18 wonderfully describes the giant ground sloth that we find fossils of in ancient rocks. The huge size with a tail that "moves like a cedar" is very understandable in terms of what has lived in the past, and the low oxygen content of our planet today explains why we do not see animals like that in today's world. The emphasis that the Bible gives to the breath of living things as seen in the Hebrew word nephesh becomes more and more relevant as we learn more about how vital that concept of breath is (see Genesis 2:7; 7:22, etc.).
Our studies of the atmosphere also help us understand the reasons for God doing things as He has in the past. Many people seem to feel that dinosaurs were unnecessary to man's existence on planet Earth, and that somehow their presence denigrates God's creative ability in the cosmos. The balance between the composition of the atmosphere and the abundance of life on the earth is critical. For plants to grow, there has to be soil. Soil is not as simple as it looks. Dirt has to have the critical elements necessary for food chains and cell reproduction, and the production of all of those resources is not simple. Plants take in carbon dioxide, and as they lock in carbon into the earth, oxygen is released to the atmosphere. The ecological system of the planet at the time at which the dinosaurs lived allowed not only soil, but massive amounts of coal and fossil fuels to form. Oil is not mushed dinosaurs, but the ecological system that the dinosaurs were a part of produced the oil and gas that we are so dependent upon.
We take air for granted, but the lesson of the past as seen in the laboratory and the fossil record tells us that the biblical emphasis on the "breath of life" is a special gift of God, and is not to be taken lightly. --Data quoted from Science News, December 19, 2005, pages 395-396.
Back to Contents Does God Exist?, SepOct06.