Things that used to be on a blog.
Like talking to a rock, I try to debate creationists
April 22, 2012
In June, 2005, I represented Australian Skeptics in an online debate against the creationists at Answers in Genesis (now Creation Ministeries International). The debate took place on the Sydney Morning Herald's Webdiary site and was conducted along the lines of a normal spoken debate, but done in writing with each team producing three papers over a week. Here is the first presentation from the side known as "Us". It was deliberately written to try to force the other side to argue the scientific case for their position, rather than the religious argument from authority that "God said that this is what happened so this is what must have happened" or the false dilemma fallacy that "Evolution theory is incomplete so it must be wrong so the world is only 6,000 years old".
I was inspired to republish this essay after seeing Eugenie Scott from NCSE twice in Melbourne, at the Global Atheist Convention and at a dinner with Victorian Skeptics.
My three contributions to the debate were published and sold by CMI in the book at the right. They did not offer me any royalties, or even a free book. I only found out about the book by accident.
Did the universe and life evolve, or was it specially created in 6 days?
The question we have been asked to address here could have the simple answer of "Yes", because the two options are not mutually exclusive. It is quite possible that the universe and life came to where they are today by a multi-billion-year process of evolution following a six-day big bang, but taking this position leaves us nothing to talk about.
This debate then is really about the evidence for two of the many possible scenarios about the origin of what we see around us today. I will call these the Creationist view and the Scientific view. I will repeat that these are only two of many possibilities. Refuting one does not automatically make the other one correct, so what is required is to evaluate the evidence for both and to compare the bodies of evidence to see which more accurately describes reality and accords with what else is known about how the universe works.
Before going on to discuss these two world views, I would like to say what is necessary to turn a hypothesis into a scientific theory. Science requires that any assertion must meet three criteria:
- Testability - This really means that the claims make predictions which can be tested for validity, either by direct experiment or by observation of regularities in what has happened in the past. "Observation" can be indirect or by inference - nobody alive today has ever seen an electron or an ice sheet covering Europe, but the theories about both result in testable predictions.
- Falsifiability - It must be possible to imagine the sort of observation or experimental result which would result in the theory being shown to be false. It is possible, for example, to imagine that under certain circumstances an increase in pressure lowers the boiling point of water. That no such observation has been made does not of itself make the relevant physics theories correct or valid, but the recognition of the possibility allows the theories to be a part of science.
- Corrigibility - Science does not claim absolute truth or complete knowledge, and any theory accepted as being scientific must allow for correction and modification as knowledge is extended and new information becomes available. This allowance must go as far as abandoning a theory completely if subsequent research shows that the observations it was based on were illusory or that the methodology used to investigate it was flawed. Newton's calculations about gravity are perfectly useful for everyday use, or even for navigating spacecraft to distant planets, but Einstein extended the theory to interactions between objects further towards the ends of the mass scale. Lord Kelvin's work on thermodynamics has been refined over the years as better measuring equipment and calculating power has become available, but his theories about the age of the Earth (which he corrected himself over the years as better data became available) were discarded completely when radioactive decay was identified as the mechanism maintaining core temperature.
Creationism makes the following claims, among others:
- The universe and everything in it was created somewhere between 6,000 and 10,000 years ago.
- The process of creation took place over six twenty-four hour days.
- The sequence of creation was (Genesis 1):
- Pre-existing water
- Light and darkness
- Heaven as distinct from water
- Dry land and oceans
- Plant life
- The sun, moon and stars
- Fish, whales and birds
- Land animals
- Man and woman
- Except when the order of creation was (Genesis 2):
- The earth and the heavens
- Plant life
- Animal life
- There was a world-wide flood about 4,500 years ago
- In this flood, all human, plant and animal life was destroyed except for eight people and the plants and animals which they had managed to load onto a boat and keep alive for just over a year
- All humans on Earth today are descendants of those eight people
- All animals and plants on Earth today are descended from the occupants of the boat
- All geological formations seen today were laid down during the eight to ten months of the flood
I will leave it up to the opposing side to provide evidence for these claims, and to say how they can be tested, the sort of evidence which would indicate that they may be false, and what action would be taken to correct or adjust them in the light of additional evidence.
The scientific position makes the following claims, again among others:
- According to the latest research, the universe is about 13.7 billion years old. The conditions and events which initially brought the universe into being are unknown at this time, but not necessarily unknowable
- The Earth is approximately 4.5 billion years old
- There are certain rules, processes and constant values which operate across space and apply throughout the universe
- Apart from an extremely tiny period of time following the universe coming into existence, there are certain rules, processes and constant values which operate across time, so that some observations made now have applied to the universe since it began and some conditions of the new universe still apply today
- Self-replicating molecules first appeared on the Earth about 3.5 billion years ago
- All life on Earth is descended from these molecules, although there may have been many originations at different times and in different places
- The enormous variety of life forms on the planet is the result of a very long process of trial and error, with many dead ends and many (but fewer) successes
- Every living organism today, be it plant, animal, fish, bacteria or whatever, has a long line of ancestors who all have one thing in common, and that is that they were able to produce viable offspring which themselves lived long enough to reproduce
None of the above claims are derived from guesswork or wishful thinking or divine fiat. All are based on the principle of Occam's Razor, that is, they reflect the best interpretation of available data and observations. They are what fits the evidence.
The scientific evidence for evolution does not come from just one source, but is derived from research in many fields of science. Some areas of science are so tightly wedded to the principle that they would cease to exist if the creationists are right. It has been said that evolution is the most important theory in all of science, simply because of its pervasiveness and what would have to be thrown away if it were wrong.
Here are just some of the sciences affected and the evidence they produce:
- Biology - All living matter on Earth shares a common method of coding for the design of the organism and for producing chemicals needed for the organism to survive in its environment. Everything has genes, genes are made of DNA, and genes are shared widely across the spectrum of organisms. Humans share 98% of their genetic coding with chimpanzees, our closest relatives, but we also share a not insignificant proportion of our genes with tomatoes.
- Geology - The physical world we see today has been produced through a long and often repeated process of vulcanism, glaciation, tectonics, erosion, sedimentation and other processes. There are reliable ways of dating both the age and the sequence of historical events.
- Palaeontology - The age and sequence of fossils support both evolution of species and the great age of the Earth
- Anthropology - There has been continuous human occupation of some locations for more than 40,000 years and evidence of the development of modern humans from ancestors hundred of thousands of years in the past.
- Nuclear physics - The mixture of isotopes in rocks and the known decay rates of radioactive elements indicate rocks of a great age.
- Cosmology and astronomy - The universe is a very big place and the edges are a very long way away.
One of the criticisms levelled against evolution is that it is "only a theory". This criticism is disingenuous for two reasons. First, the word "theory" has a specific meaning within a scientific context and it means an idea which has enough evidence to support it such that rejection would require not just philosophical arguments but disconfirming evidence. Second, it is a strawman argument. Science is always a work in progress. The fact that the theory of evolution cannot provide absolute answers to all questions about the origins of life does not invalidate the theory any more than the fact that research has not yet uncovered a cure for cancer invalidates medicine or the fact that oil companies drill dry holes invalidates geology. The world-wide scientific community exists just because there are unanswered questions. That is what science is and is for. Science does not have a book which states absolute truths - if it did it would be religion, not science.
All science expects of a theory is that it be testable, falsifiable and corrigible. The theory of evolution is all three. Creationism is none of the three. The evidence for evolution is overwhelming. The evidence for special creation is non-existent.