This is the text for lessons in the Science and Religion Adult Sunday School series at St. Francis of Assisi Episcopal Church in Chapin, SC, April 6-May 18, 2008
Religious Notes
Genesis 1:1-2:3, In these verses we are told that it was not until the 5th day that the first animals, fish and birds, were created. The rest of the animals, including humans, were created on the 6th day. There is no doubting the meaning; all life comes from God.
Isaiah 42:5 “God created the heavens and spread forth the earth. He gives breath to the people on it and spirit to those who walk on it.”
1 Timothy 6:13 “In the sight of God, who gives life to everything…”
Job 33:4 “The spirit of God has made me, the breath of the almighty gave me life.”
Psalm 100:3 “Know the Lord is God. It is he who hath made us, and we are his. We are his people, the sheep of his pasture.”
Psalm 139:13-16 “For you created my inmost being; you knit me together in my mother’s womb. I praise you because I am fearfully and wonderfully made; your works are wonderful, I know that full well. My frame was not hidden from you when I was made in the secret place. When I was woven together in the depths of the Earth, your eyes saw my unformed body. All the days ordained for me were written in your book before one them came to be.”
Proverbs. 22:2 “Rich and poor have this in common: The Lord is the maker of them all.”
Isaiah 64:8 “Yet, O Lord, you are our Father. We are the clay, you are the potter, we are all the work of your hand.”
Jeremiah 27:4, 5 “Give them a message for their masters and say, ‘Tell this to your masters: With my great power and outstretched arm I made the Earth and its people and the animals that are on it, and I give it to anyone I please.’”
Hebrews 12:9 “Moreover, we have all had human fathers who disciplined us and we respected them for it. How much more should we submit to the Father of our spirits and live!”
1 Corinthians 8:6 “yet for us there is but one God, the Father, from whom all thing came and for whom we live; and there is but one Lord, Jesus Christ, through whom all things came and through whom we live.
Science Text
The origin of life remains one of the most important questions for which modern science has not formed a consensus. In order to try to understand how life might have formed, let us begin with a discussion of what we do know, and let us begin that discussion with what the study of geology has taught us.
For many years, geologists thought the earliest life forms were those obviously marine organisms seen in rocks dating only from about 540 million years ago, the start of the Cambrian Period. In part that was due to the fact that, until the 20th century, most biologists and geologists considered all living things to be classifiable as either a plant or an animal. But in the 1950s and 1960s, biologists came to the realization that this system failed to accommodate such life forms as fungi, protists, and bacteria. By the 1970s, a system of Five Kingdoms had come to be accepted as the model by which the model by which all living things could be classified could classify all living things. In 1979, an entirely new group of organisms, different from all of the above, was discovered. Currently, biologists recognize more fundamental levels of organisms – eukaryotic kingdoms (plants, animals, fungi, & protists), the prokaryotic kingdom (bacteria), and Archaea (bacteria-like but with significant differences).
Earliest Life-forms
The earliest forms of the biosphere first appeared approximately 3.8 billion years ago, during the Pre-Cambrian Eon. These forms were bacteria-like and were probably anaerobic, organisms that do not need molecular oxygen for metabolism, and heterotrophic, organisms for which organic compounds were their primary food source. Approximately 2.5 billion years ago, life forms evolved that used photosynthesis to produce atmospheric O2. The rise of single celled plants coincided with the time that atmospheric O2 had become so abundant that it was toxic. Organisms had to be able to survive in an O2-rich atmosphere. Thus the rise of organisms that employed aerobic respiration. Aerobic respiration is a much more efficient process than anaerobic respiration. As a result larger cells could form and the potential for multicellular organisms was put in place.
Earliest Obvious Life – Marine Invertebrates and the “Cambrian Explosion”
At approximately 540 mya (million years ago), the start of the Cambrian Period, an explosion of life occurs. During the 40 million years attributed to the Cambrian, all existent phyla develop, including many marine invertebrate animals (marine animals with mineralized shells: shell-fish, echinoderms, trilobites, brachiopods, mollusks, primitive graptolites). The first vertebrate animals and the earliest primitive fish also appear. Interestingly, there was also a mass extinction of trilobites at the end of the Cambrian, thought by some to be due to glaciation.
Land Plants
During the Ordovician Period (505 to ~440 mya), the first primitive land plants appear, as well as the more primitive fishes. During the Silurian Period (440 – 410 mya), the first vascular land plants appear.
The Age of Fishes
Sharks and more advanced types of fishes first appear during the Devonian Period (410 -360mya). Also, land plants become abundant, and we see the first appearance of amphibians.
The Coal Age
We see abundant coal deposits in rocks of the Carboniferous Period (360-280 mya), indicating an abundance of land plants. We also see the first appearance of reptiles and insects, including winged insects.
The Age of Amphibians
Amphibians and reptiles dominate the landscape during the Permian Period (280-250 mya). The life activities of plankton and plants cause the atmosphere to become enriched in oxygen to approximately present-day levels. The Permian Period ended with one of the greatest mass extinctions, including 50% of all animal families, 95% of all marine species and many trees.
The Age of Dinosaurs
Dinosaurs first appear, then become the dominant form of life, and then become extinct during Mesozoic Era (the Triassic, Jurassic and Cretaceous Periods, approximately 250 – 65 mya). During this time we also see the first appearance of mammals and true birds, which may have evolved from the dinosaurs. The end of the Mesozoic came with another huge extinction, including 50% of marine invertebrate species as well as the dinosaurs. This was probably caused by a meteorite or asteroid impact.
The Age of Mammals
Mammals become the dominant life form during the Cenozoic Era (the Tertiary and Quaternary Periods – 65 my – present). The “Age of Humans” comes during the Quaternary Period (~1 mya – present). This will be the topic of the next lesson.
Origin of the first life form
OK, but how did life begin, from the point of view of scientists? Before the middle of the 17th century, most people believed that God was the Creator of all life forms. But that was not an answer that scientists accepted, because that answer was not testable as good science should be. Since that time, science has become progressively more sophisticated, and science is making important advances that impact on the question of how life began.
Louis Pasteur showed that the concept of spontaneous generation was incorrect. He discovered that even bacteria and other microorganisms are the progeny of similar life forms. However, that discovery did not answer the question as to from where did the first forms of life come.
Scientists now believe that the last of the sub-systems of the Earth System, the biosphere, is thought to have come about through chemical processes in which inorganic compounds combined to produce organic chemicals which in turn somehow became living cells. But, to understand how we even came to this conclusion, it is necessary to understand some basic chemistry of life processes.
All known forms of life are comprised solely of biomolecules. Biomolecules are combinations primarily of carbon and hydrogen, along with nitrogen, oxygen, phosphorus and sulfur. Other elements sometimes are incorporated but are much less common. Examples of biomolecules include, but are not limited to proteins, amino acids, vitamins and sugars. Prior to the middle of the 17th century, it was generally believed that only living beings could produce the molecules of life (from other, previously existing biomolecules). But biomolecules could not have formed in an oxygen-rich atmosphere, such as there is on Earth today. This led to the conclusion that the chemistry of the Earth’s early atmosphere was different from what is today. In an early experiment, Stanley Miller and Harold Urey created an artificial ocean based chemically on the composition of the early Earth atmosphere, which was thought to have contained methane, ammonia, water and hydrogen. They then subjected this “atmosphere” to “lightning” (in the form of electrical arcs). When the products of this experiment were identified, they found that some of the carbon had been transformed into organic molecules, including amino acids. The discovery of amino acids was particularly exciting, because these are the building blocks of proteins. Their conclusion was that an Earth with an oxygen-poor atmosphere and oceans containing carbon and hydrogen (from methane), oxygen (from water, not as gaseous O2) and nitrogen (from ammonia) could produce simple biomolecules like amino acids. But, the big question that still remains is: How did the Earth get from making simple biomolecules to making more complex biomolecules that are able to self-replicate, a process that is necessary for the origin of life. There is no consensus yet on how exactly that process occurred, but it has been shown that, with time, biomolecules, with the help of catalysts, could be transformed into more complex, self-replicable biomolecules.
Evolution
Now that we have some information on what scientists know and don’t know about the origin of life, let’s move on to look at how scientists explain how many different life forms might have changed over time and how life forms came into existence throughout the geologic record.
In 1831, a young naturalist named Charles Darwin set sail from England on the H. M. S. Beagle. Darwin did not set out to “discover” evolution, although the data that he collected on that fie-year expedition led to the publication in 1859 of his book, On the Origin of Species, in which he proposed that organisms change, or evolve, over time. Even though Darwin is credited with being the founder of the theory of evolution, it should be mentioned that idea basic idea of change over time was first suggested before Aristotle. In the late 1700’s and early 1800’s, another naturalist and geologist, Jean Baptiste Lamarck proposed that all species, including humans, descended from similar but less complex forms. Today, biological evolution is considered to be the change in the inherited traits of a population from generation to generation.
Darwin’s greatest contribution, and one that had not been made before, was to propose a valid mechanism for evolution. His proposal, which is generally known as “natural selection”, is still the basic framework of our understanding of how evolution works. Natural selection is based on five premises:
* Organisms result in like organisms – there is stability in reproduction.
* In the case of most species, many more individuals are produced than the number of those that survive and reproduce.
* In any given population of individuals, there is some variability and that variability can be passed on to later generations.
* The determination as to which individuals will survive and reproduce is determined by the interaction of the variations and the environment. Favorable traits allow individuals to survive longer and reproduce more offspring, i.e., become more common, whereas harmful traits become rarer.
* Over a long enough period of time, natural selection can lead to the accumulation of changes that differentiate later groups of organisms from earlier forms of the same organism.
At this point, we should also define a species as a group of organisms that can reproduce with one another. When a species is separated into populations that are prevented from interbreeding, mutations and the favoring of different traits by different environments result in the formation of a new species.
Evolution of Horses
The fossil record illustrates a number of stages in evolutionary history. Prime examples include the evolution of elephants and horses, both of which have evolved over the past 50-60 million years. Each has followed an evolutionary path that has resulted in several different species and all moving from the less complex to the more complex.
Still, while there is definitive evidence that evolution has occurred and the theory of evolution can help us understand how organisms have changed over time in the past, evolution cannot accurately predict how, or even if any particular species is going to evolve in the future. This is because natural selection is driven by genetic mutations and genetic mutations, while not absolutely random, are certainly unpredictable.
Further, despite the fact that the fossil record illustrates a number of stages in evolutionary history, there are numerous gaps in the record. Darwin himself noted in On the Origin of Species that the geologic record is “…a history of the world imperfectly kept, and written in a changing dialect; of this history, we possess the last volume alone, relating only to two or three countries. Of this volume, only here and there a short chapter has been preserved; and of each page, only here and there a few lines.” To be sure, since Darwin’s writing, fossil records in more countries have been explored and gaps in more of the fossil record have been filled in. Still, there are probably more gaps in the fossil record than biological and geological scientists would like to see.
To that end, two paleontologists, Niles Eldridge of the American Museum of Natural History and Stephen Jay Gould of Harvard University published a radical proposal that noted that the fossil record, overall, does not support only the kind of gradual evolutionary change over time that Darwin proposed. They called their model punctuated equilibrium. They proposed that for many organisms, a species lasted for 5-10 million years undergoing little change, only to become extinct. Shortly (geologically speaking) after that a new species, similar but obviously a different species, would take its place, with no evidence of gradual change. This second species would often mimic the earlier species, lasting 5-10 million years with little change, disappear and be replaced by other, similar, but different species.
Extinctions
Not only do organisms change over time, many of them die off completely. Extinctions encompass a scale from species to entire groups of organisms. In fact, only a very small fraction, far less than 1% of those species that ever lived are still alive today. Extinctions occur both individually and en masse. Individual species become extinct at a rather steady rate of 200-300 per million years, when they are no longer able to compete. However, there are periods in the geologic record when extremely large numbers of species become extinct over a very short period of time. One of the largest of these mass extinctions occurred approximately 250 million years ago, marking the end of the Permian period. At that time 80-85% of all living species became extinct. Another famous extinction occurred approximately 65 million years ago, marking the end of the Cretaceous period, when all living species of dinosaurs, creatures that were extremely hardy and adaptable, and numerous other species of terrestrial animals became extinct.
A very great amount of research has gone into finding the causes of mass extinctions. It is well established that a meteorite, with a diameter of approximately 10 kilometers, impacted Earth at the end of the Cretaceous period and was the ultimate cause of the mass extinction that included all of the living species of dinosaurs. Meteorite impacts of this magnitude can cause clouds of debris to be thrown into the atmosphere, circling planet Earth for months, extinguishing much of the sunlight, slowing or ceasing photosynthesis and strongly limiting food supplies. Even so, after a mass extinction, many organisms are still able to compete, live and reproduce. New species occur, and the evolution of life goes on.
Reflective Questions
1. How do theistic scientists reconcile biblical and scientific accounts of the origin of life?
With respect to the origin of life, “science cannot present a detailed, step-by-step account of the origin of life from non-living matter…”(Miller, K. R. Finding Darwin’s God). Accepting this idea, we can see that there is no proof from scientific research that life originated purely from naturalistic causes and therefore, science cannot disprove the belief that the first living cell was he direct, miraculous, intentional work of a Creator.
Fred Hoyle, the eminent astrophysicist who is credited with coming up with the idea of the Big Bang to explain the origin of the Universe once said: “Once we see, however, that the probablilit of life originating at random is so utterly minuscule as to make it absurd, it becomes sensible to think that the favorable properties of physics on which life depends are in every respect deliberate… It is therefore almost inevitable that our own measure of intelligence must reflect…higher intelligences…even to the limit of God…such a theory is so obvious that one wonders why it is not widely accepted as being self-evident.”
2. With respect to biologic evolution, what is the fundamental difference between the views of most scientists and the views of Creationists?
Creationists tell us that the Bible informs us that God created the Universe and all life forms and therefore it is not necessary to try to understand these matters using science.
Scientists seek to understand how the Universe and all its components work, through the natural laws of physics, chemistry, biology and geology. While the scientific view of how the Universe works does not need God, theistic evolutionists, of which I am one, believe in both God and evolution, and do not see any conflict in this and actually need God in order to gain a more wholistic view of the Universe, our Solar System, the Earth and all life forms. We believe that since science has not been able to replicate the origin of even the simplest of living cells, we can’t rule out the fact that life was first created by God! In fact, it makes sense to me that God must have created the first life form, and then put in place the processes of evolution by which all other life comes into existence, changes and dies. It can be argued, even using the Creationists’ arguments, that God gave us a complex brain as well as a soul, and that with our complex brain, the ability to think, to question and to reason. Why should we not use that brain to understand nature in terms of natural laws, now that we have all of our previously gained scientific knowledge?
3. But, isn’t biologic evolution just a theory?
From the Episcopal Church’s “Catechism of Creation”, we read: “Theories are not mere guesses or hypotheses, as people often suppose. When enough evidence supports a hypothesis that has been created to explain some facts of nature, it becomes a theory…Biologic evolution is a web of theories strongly supported by scientific observations and experiments. It fits in with what we know about the physical evolution of the Universe, and has been confirmed by evidence gathered from the remains of extinct species and the forms and environments of living species.
4. So, why is evolution so controversial?
For many, perhaps most, people, there is no doubting the meaning of the verses in the Old and New Testaments – God is the creator of life – and they object to the idea that all diversity in life, including human beings, arose through natural processes without a need for supernatural intervention. Some also argue that evolutionary common descent degrades human beings by placing them on the same level as other animals, in contrast with past views of a great chain of being in which humans are above animals.
Since the publication of Darwin’s “The Origin of Species” in 1859, evolution has been a source of nearly constant contsroversy. iN general, controversy has cent ered on the philosophical, social, and religious implications of evolution, not on the science itself. The theory that biological evolution occurs through the mechanism of natural selection is competely uncontested within the scientific community and many religions, including Anglicans and Roman Catholics, have reconciled their beliefs with evolution through theistic evolution.
While many concepts in other fields of science also conflict with a literal interpretation of many religious texts, evolutionary biology has borne the brunt of these debates.
5. What exactly is meant by “Intelligent Design”?
Many people outside the scientific community believe that certain features of the Universe and of living things are best explained by an intelligent design, not an undirected process such as natural selection. This is a modern form of the traditional teleological argument for the existence of God, that is, an argument for the existence of God or a creator based on perceived evidence of order, purpose, design and/or direction in nature. Although intelligent design has been modified to avoid specifying the nature or identity of the designer, its primary proponents believe the designer to be the Abrahamic God. Advocates of intelligent design claim it is a scientific theory, but since it involves the concept of an Intelligent Designer that cannot be tested or proven, it fails that test. Furthermore, there is a record of biologic evolution of the eye in the geologic record, from simple variations that worked for some organisms to progressively more complex systems that worked better for different organisms, making these later organisms more adaptable and better able to survive. The scientist will ask: If each of these organisms, with progressively more sophisticated “eyes” was separately created by some Creator, why did it take him/her so long to get it right?
