The Origin of Life

The Answers in Genesis (AIG) newsletter of June 13, 2003 asks, "How can scientists investigate life's origin when it supposedly occurred so long ago?" Their answer concludes science is not up to the task:

"It's a big problem. Think about this--in 1995 there was a murder trial involving a famous athlete that went on for many months. If lawyers and the forensic scientists had such a hard time trying to reconstruct an event that occurred just months earlier, how can scientists ever reconstruct what happened supposedly millions or billions of years ago? Do creationists and evolutionists argue about photosynthesis, how a computer works, or how to put up a space shuttle? No, they don't disagree about those things. But do they argue about origins? Most definitely! So what's the difference? Current technology deals with what we can observe in the present. But, when it comes to origins and the past, this is outside real science because we don't have the past with us! In Genesis, though, we have a record of a witness Who has been there in the past. This is the basis for TRUE science."

The AIG contends that without a witness science is stuck "because we don't have the past with us." The work of lawyers and forensic scientists is admittedly hard. Because that work is hard, it doesn't mean that crimes are not worth investigating or will necessarily remain unsolved, however. A knowledgeable and persistent detective can often find just the clues they need for a solution and conviction. Sometimes, all it takes is a showman lawyer whose rhyme and charges of racial bias causes the jury to disregard all of the (admittedly complicated) DNA evidence.

The AIG question is actually two questions: What is the origin of life? And, how do scientists investigate the past? The origin of life question remains unanswered. In fact, evolution, including Darwin's work, is concerned with the origin of the observed diversity of life (the origin of species) and not the origin of life. Experiments have shown how chemicals characteristic of living things could have been made from components of Earth's early atmosphere. Or, life may have begun as complex chemical interactions in the vicinity of hot, metallic, sulfur-rich springs at the bottom of dark oceans. There is also evidence that clay may have acted as a catalyst that hosted self-reproducing chemicals. It may be that life originated somewhere else in the universe and made its way to Earth on comets or meteorites. As yet, there is no clear winner in this debate. Until we reach other planets and star systems and have other examples of life, this question will likely remain unanswered, but that doesn't mean the question is unanswerable. It simply means that for now, the only way we have available to directly investigate origins relies on fossils and the chemical reactions that were the precursors to life didn't leave traces ("fossils") that we know how to detect. It is sufficient (but not scientifically satisfying) that sequences of chemical reactions that produce those precursor chemicals of life can be demonstrated.

We do have the past with us; the rock record is around and underneath us. Using the basic principles of geology, the rocks around us can be ordered, oldest to youngest. Once placed in that context, methods for studying the past go far beyond just identifying fossils. To list a few techniques, rocks are photographed, classified, tasted, hammered, blasted, cut and polished into micro-thin wafers, examined with microscopes, dyed, crushed, sieved, dissolved in acid, x-rayed, CT-scanned, and tested with Geiger counters. Structures in the rocks (mud cracks, worm burrows, roots, soils, crossbedding, and others) are described, counted, and measured. The relationships of a rock unit to those above it, below it, and laterally equivalent are studied.

All of this information is compared to processes and rocks we can see forming today. Was rock formed by the action of a volcano, water, wind, ice, earthquake, storm, or landslide? Was it formed in a lake, beach, river, swamp, forest, flood, or desert? Did water flow back and forth, like tides, or in just one direction, like rivers? Was water deep or shallow, fast, slow, or still, or fresh or salty? Current technology allows geologists to make observations and conduct experiments that lead to answers to all these questions. This detective work combined with the relative geologic time scale and radiometric age dating enables us to answer more questions. When was this area a lake? Where were the rivers and mountains when that soil formed? How old is the Atlantic Ocean?

Some of the investigations are as detailed and painstaking as any murder investigation. In Trilobite: Eyewitness to Evolution, Richard Fortey describes one researcher who spent a lifetime examining the trilobite fossils in a single rock unit. After examining thousands of specimens, the paleontologist showed that rather than many species of distinctly differing sizes and number of body segments his trilobite fossils represented different life stages of the same species from larva to adult.

Geologists and paleontologists are the detectives of the Earth's past. Wherever there are rocks on the surface or deep within the Earth, scientists are looking at them. Understanding this past is essential to our future. For example, to better know the effect of greenhouse gases on Earth's climate, we need to know how Earth's climate has changed in the past, what caused those changes, and how those changes affected living organisms. These are the types of problems "real" and "true" scientists can investigate by interrogating our witnesses, the rocks.

Fossils and Circular Reasoning

Ken Ham's organization, Answers in Genesis, publishes a weekly newsletter in which he poses a series of questions that are supposedly impossible for scientists to answer in an acceptable fashion. He then provides an answer, eponymosly derived from Genesis, that is authoritatively supposed to trump science. I don't know if AIG maintains an archive of these newsletters at their web site, but I do. I need to post more regularly here and so, I'll begin answering Ken Ham's questions.

The AIG newsletter of March 3, 2003 asks, "How do evolutionary scientists date fossils to get such OLD dates?" Their answer posits that science gets it wrong.

"It’s hard to believe, but the fossils date the rocks that they’re in, and the rocks date the fossils they’re in! The main evidence for evolution is the fossil record. Supposedly, this is a record of the evolution of life, with the oldest and simplest creatures at the bottom and the younger and more complex forms at the top.

"But the fossil sequences are actually based on a belief that the Earth is millions of years old. And the geologic ages of millions of years have been built upon the basis that the idea of evolution occurring over millions of years is true. Isn’t this circular reasoning? It certainly is. In fact, evolutionary thinking is full of that kind of circular reasoning.

"Biology professors tell you the geologists have the evidence for evolution; geology professors tell you the biologists have the evidence for evolution. In reality, the evidence doesn’t fit with evolution, but it DOES fit with what the Bible records in Genesis."

The AIG answer misrepresents both geology and biology. The geological and biological branches of science both have separate lines of evidence supporting evolution. And, yes, geologists and biologists both cite literature from the other field. I am and a geologist and will answer Ken Ham geologically.

How do geologists use fossils and how are dates determined? Each branch of science is based on some fundamental principles. The periodic table in chemistry and conservation of matter and energy in physics are examples. The founding principles of geology are:

1. (Nicholas Steno, 1638-1686) Superposition. In an undisturbed sequence, a rock layer is younger than the layer upon which it rests and older than the unit that rests on it.

2. (Steno) Original horizontality. Sedimentary rocks were originally deposited in nearly flat layers.

3. (Steno) Lateral continuity. Within the limits of a particular environment, you can match similar sequences of rocks from one area to another, across a valley, underground, and even between continents.

4. (James Hutton, 1726-1797) Cross-cutting relations. A fold, fault, or volcanic rock is younger than the rock units it effects.

5. (Hutton) Unconformities. Some boundaries between rock units represent significant time during which either no rocks were formed or pre-existing rocks were removed by erosion.

6. (Hutton) Uniformitarianism. The “present is the key to the past” idea. Environments and processes we see shaping the Earth around us today can be used as models for what happened in the past.

7. (William "Strata" Smith, 1769-1839) Faunal succession. The fossils in a rock unit are unique to that unit. This modern name implies change through time, but succession is a more recent idea than the original concept. Charles Darwin didn't publish Origin of the Species until 20 years after Smith died.

For more on this, see my Principles of Geology post.

Careful application of these ideas led to the development of the relative geologic time scale, a "Table of Contents" for past Earth history. With the scale in hand, geologists could say, “this rock is older than that one.” Geologists and paleontologists could observe the change of fossils from one unit to the next. For example, fossils of trilobites [oldest], dinosaurs, and humans [youngest] do not occur in the same rock layers.

To answer the question of how much time, scientists had to wait until the discovery of radioactivity and the development of radiometric age dating. Some rocks and minerals preserve traces of radioactive elements and their decay products. These elements can be used as a clock. The amazing thing is that radiometric age dating confirmed the order of rock units established by the relative geologic time scale.

Fossil sequences are not based on the "belief that the Earth is millions of years old." Rather, rock units were ordered according to the Relative Geologic Time Scale. AIG says, "fossils date the rocks that they’re in." No, the fossils in a rock unit are used to help place it in the context of the relative geologic time scale. For example, if you are looking for dinosaur fossils and you find a rock with trilobites, you know you need to look somewhere else. AIG also says, "the rocks date the fossils they’re in." Radiometric age dating establishes absolute ages of certain rock units. In an undisturbed sequence of rocks, the absolute age represents the youngest possible age for all rocks it rests on and the oldest possible age for all units that rest on it.

The claim of circular reasoning in AIG's first paragraph is invalidated by the manner in which the geologic time scale and absolute age dating techniques are used. Geologic principles and the beginnings of the relative time scale were developed before Darwin and are not based on the assumption of millions of years. As the relative time scale was developed, geologists realized it certainly took much longer than 6,000 to 10,000 years for the rock sequences to develop, but they had no good idea how long until radiometric age dating techniques were developed. Finally the claim that geological citation of biological lines of evidence and biologists citing geologists is a straw man argument fabricated simply to discredit both branches of science.

Guppies

AIG recently posted a newsletter item (21-July-2007) that asked "Can speciation occur quickly?" Not surprisingly the answer is yes and the basic evidence is that all of the species we see today are descended from the "kinds" (a term not in the newsletter) that were on the Ark. Evolutionists, because of their insistence that speciation occurs over geologic time (millions to billions of years), must be wrong.

AIG has often been accused of the sin of "quote mining," accurately quoting some authority out of context in such a way that the cited text represents a position completely opposed to the thesis of that authority. This newsletter item exhibits a mined quote of a different sort. As presented by AIG:

But in the journal Science, a report stated:

“These examples say that natural selection can cause a population to change very quickly and hint that speciation could [occur] very quickly …”

This statement is followed by the conclusion "true operational science confirms Biblical history."

What nonsense. No reference to the report or article is provided; it could be a letter to the editor written by AIG staff. Nothing is known about what the examples might be or what is meant by "very quickly." To an evolutionist (in this case, a geologist or paleontologist), very quickly can mean any time period from less than a second to a couple of million years; the quote provides no context for establishing the time scale.

Worse still, AIG has conflated quick change with speciation. This becomes pretty obvious when you visit the page on speedy speciation linked in the AIG newsletter. Here we meet the AIG version of a guppy story. Guppies in Trinidad were transplanted into a pool (previously without guppies) above a waterfall. These guppies matured later, became bigger, and had fewer offspring than those in the predator-filled pool below the falls. Again, "quickly" remains undefined by AIG; time should be in terms of the number of generations of guppies it took for these adaptations to occur. (Maybe the original article in "Science" has this information, but AIG won't tell you.) A more pressing problem is the question: were the observed adaptations sufficient to give rise to truly separate species?

Or, were the adaptations simply a response to an environment with fewer predators and plenty of food? In the United States, there are many environmental factors that have changed over the last 200 years or so (an extremely quick blink of the eye in geologic and evolutionary time) that are giving rise to the same sorts of changes. High quality food items are available in many varieties. Our healthcare system is widespread and generally accessible. Sanitation, clean air, and clean water are priorities. A visit to the museums in Jamestown or Williamsburg, cities founded by early European settlers, will reveal adult shoes that are almost unimaginably tiny compared to our modern feet. Men and women exceeding 6 feet in stature are no longer uncommon. American humans are changing relatively rapidly within a favorable environment. However, there is no Homo norte-americansis; no separate species. Given enough time and the political will to enforce isolationist political policies (i.e., geographic isolation in evolutionary terms), those adaptations might lead to the evolution of a separate species.

Has AIG made a case for rapid speciation? No. Given the failure to define the time periods involved, the failure to adequately reference any of their statements, and the invalid assumption of the equivalence of adaptation with speciation, it is fair to say they have again only slain their own straw man.

12/6/2007: In reading this post, I note that I made an error in logic. It can be concluded that I conflated rapid speciation as being somehow inconsistent with evolution. It isn't. There are plenty of relatively rapid speciation events, including some that are happening on laboratory time scales well within the span of a human lifetime that are cited at many sites, for example search for "rapid speciation" at TalkOrigins.

Foundations of Science

When addressing the questions invoked by debate between scientific and religious viewpoints, it is appropriate to look at their underpinnings to arrive at a how and why science is successful in doing what it does. Unfortunately, such an examination must delve into topics for which only philosophical discourse exists and not answers. I'm not a philosopher and will likely mangle any number of subjects, but they are worth thinking and discussing on the way to understanding.

The natures of consciousness and reality are problematic to say the least. We have to start somewhere (nihilists not withstanding) and so I'll start with consciousness. Consciousness seems to be a confluence or interaction between thought, emotion, and self-awareness. Many belief systems, especially the Abrahamic traditions (Judiasm, Christianity, and Islam) will readily identify consciousness with the soul. It is that which makes humanity unique, that is saved or lost, and that perseveres forever in heavenly bliss or eternal damnation. Modern neurochemists feel they are on the verge of determining the biological nature of this aspect of humanity. Whether consciousness is a quality bestowed upon us or it arises from biochemical activity, it is what makes each of us a "self."

That self interacts with our surroundings by the senses at our command. Taste and touch act in our immediate vicinity. Smell and sound are a bit more far reaching. Sight, however, can operate over vast distances. Everything our selves perceive are filtered through the narrow windows of these senses and then processed by the conscious mind. What is it that we perceive? It is nothing less than the "reality" in which we are immersed. There are two possibilities for the nature of reality: objective or subjective. In an objective reality, we and the universe in which we exist operate according to specific principles (laws) that exist completely apart from whether we understand those principles. Subjective realities, on the other hand, open up the possibility that the universe may operate in the manner we believe it does. Subjective universes allow that if sufficient numbers of people believe in ghosts, then they exist. This is an "it's true for me" viewpoint.

Dr. Susan Blackmore argues that because of the nature and limitations of our senses, objective realities don't exist; each of us live in the reality of our own making. However, she continues, unless we pretend there is an objective reality then existence is without meaning. (I heard an interview with her on the Guardian Unlimited Science Podcast of April 23, 2007. This is difficult philosophy and I may have made mistakes summarizing Dr. Blackmore's thesis.)

So, then, where does this get science and religion? Basically, each of us, a collective of conscious entities, perceive a reality for which there is a consensus about the way that reality works. It is at this point that science and religion diverge. Religion takes the tact that those things revealed in a sacred text and affirmed by itself to be true are, in fact, true statements about the nature of reality. An omnipotent and omniscient God created the universe 6,000 (+/-) years ago. That God tossed humanity out of Eden because the first woman ate an apple and thus condemned all the generations of Man to existing in sin which can only be forgiven if a person accepts the death and resurrection of a man/god/part of a 3-for-1. Faith and belief (existing without and often in spite of evidence) are the basis of this reality.

In science, reality has rules. There is a way the universe works that isn't capricious and that humanity can (eventually) understand. In a very fundamental sense, science is about building a consensus on how a reality works. Science makes the assumption that reality is objective. Once that assumption is accepted, it becomes possible to accumulate a consistent body of evidence-based knowledge that is consistent with and demonstrates particular claims about the nature of reality: the Earth orbits the Sun, the surface of the Earth is comprised of plates that move respect to each other, life evolved. In science, if someone proposes a weird idea, they must be ready to present their evidence and methods for testing and verification by others. In some cases, ideas languish for lack of evidence (continental drift), are dismissed as self-delusion (N-rays), or are revealed as frauds and hoaxes (Piltdown man).

When science makes claims about the nature of reality, those supporting the claims are obligated to present evidence. If that evidence is found to be insufficient to support the claim, it must either be abandoned or revised. Science readily does this and is often criticized as so fluid as to be meaningless. (Whatever happened to the Brontosaurus?) It is this progressive change that differentiates science from religion and is the basis of the success of science.

Starting points and viewpoints

Creationists challenge those who do not hold their opinions to be open minded and they criticize scientists for being closed minded for failing to consider the creationist position. Creationists also state that they are scientists doing scientific things, it is just that they have a different starting point than evolutionists. All of these assertions make an appeal a reasonable fair person, why then is the creationist position so rejected by the scientific community?

One of the main points where the scientific and creationist viewpoints diverge is that "starting point," the age of the Earth. On the authority of Genesis, creationists assert that Bishop Ussher's 6,000 year (+/-) estimate of the age of the Earth is true. The bulk of the arguments presented in support of their hypothesis consist of attempting to demonstrate that various processes occur very quickly (rapid burial of coal, fossilization of creatures giving birth, etc) or that the Earth would be a very different place "if it were as old as evolutionists say" (all continents eroded to sea level, seas filled with sediment, seas saltier, ¹⁴C at equilibrium, etc.).

Scientists started with the same viewpoint as did creationists. There was a time when the age of the Earth, on Biblical authority, seemed to be young, and Bishop Ussher, using genealogy and other text clues set the date of creation to about 4004 BCE. However, as people began looking at the world around them, this date was not consistent with physical evidence. The layered rocks weren't formed as the result of a single event; they weren't even formed by one single process. Rather, the layered rocks were formed by many different processes. From this point, scientific and creationist views diverged; scientists realized that on human terms, Earth is unimaginably old. From this viewpoint, scientists say, yes, some coal was buried quickly, but there are many different coal layers. Formation of coal and burial occurred not once, but thousands of times. Rapid burial is a condition necessary for preserving fossils; without rapid burial, scavengers and decomposers scatter and break down the body and bones so that no remains are left.

Are scientists open-minded? There are scientists who have developed a cherished idea and have force fit all observations and evidence into that framework. That is the weakness of an individual. Science, however, has a requirement that an idea be reproducible and verifiable by others. A scientist starts with evidence and comes to conclusions. OK, I will concede at this point that scientists operate within a framework of the evidence and ideas of their predecessors. Scientists, don't automatically assume their predecessors are correct. What real scientists do not do, is pledge that no matter what they do, it will always and invariantly be in compliance with a preconceived notion revealed in a sacred text.

Creationists do not appear particularly scientific or open minded. If one chooses data on the basis of whether it demonstrates a preconceived idea and rejects contrary information, if one repeats the same arguments and holds to the same idea in the light of new information, these are the hallmarks of someone who is not doing science.

Science and Religion

On the question of religion and science, faith-based ideologies have not fared very well in judging the validity of science-based propositions especially when science is in apparent conflict with revealed knowledge as set forth in sacred texts. Galileo demonstrated that Copernicus was right about the structure of the Solar System, but it took the Catholic Church centuries (1737 to 1992) to express regret over the supression of his work. Evolution is another idea that stands in opposition to sacred teachings. Stephen J. Gould sought a way around direct conflict by suggesting that religion and science were "non-overlapping magisteria." Science and religion exist in parallel but don't come into conflict because they answer different types of questions: religion examines who and why, whereas science examines how and when.

Richard Dawkins rejects Gould's ideas as soft peddling to vocal religious minorities. Dawkins and Victor Stenger posit that religion makes certain claims about the way the world (or universe) works and have the chutzpah to say those propositions can be investigated scientifically (the reason Dawkins rejects Gould's NOMA idea). Sam Harris rejects faith in general as a very dangerous and divisive idea. Eugenie Scott sees a continuum of belief systems from literal flat-earth fundamentalists to atheism. Eugenie Scott and E.O. Wilson feel that religious moderates who accept scientific propositions can be enlisted in the campaign to increase scientific literacy.

The majority of folks, when they consider the question at all, are somewhere in the middle: accepting of religion and sacred texts, but also accepting of science and its findings. Often the debate makes them uncomfortable. When questioned, the controversy seems to require them to make a definitive decision one way or the other with no middle ground. For a politician, accepting a concrete position is establishing them as a target whereas waffling offends the fewest number of potential voters. Personally, I think taking this middle ground is why most of the opinion polls show a high percentage of persons who reject evolution. The poll questions are often phrased so the respondent either has to reject God or choose among faith-based answers. Most will choose an answer that is flavored by their faith.

It turns out that the vast majority of religious persons are religious and accepting of particular traditions for no better reason than that their parents were religious and passed those traditions to them. As thinking and educated adults, no one I know of has embarked upon a comparative study of religion to determine which is the most satisfying (or "truth full" if you will). Most people are simply indoctrinated as children. [I know this is simplistic and cynical, but psychologically and developmentally it is true. Why is someone Baptist instead of Presbyterian, Methodist, Catholic, or Muslim?]

The point I am getting to is that religious persons who endorse scientific propositions have accepted a fundamental proposition: the sacred text on which their faith is based (Bible, Koran, or other) is not literally true in all its aspects and was not transcribed without error from direct communication with a creator. In other words, they have chosen to disregard outdated or inconsistent parts of their particular sacred text. The canonical works become a guide to morality and ethics, a source of hope and inspiration. This redacted framework then does not come into conflict with the fact that today we simply know more about the way the world works than was known thousands of years ago.

It has been stated by Dawkins and others that there is only one group of persons who are not electable. We have politicians at local, state, and federal levels who are Jewish, female, Muslim, African-American, bi-racial, Puerto Rican, Irish, Italian, Baptist, Catholic, and all other denominations. But of all the diverse groups, no candidate has ever run on an Atheist platform or stated before an election that that was their position. Maybe, a Secular Humanist could be elected because many voters wouldn't know what that was. But, if you run a Baptist against a Secular Humanist, my bet is the Baptist would be a shoe-in.

Stories in rock

Most people notice the different layers, thicknesses, and colors of rocks. They are the ubiquitous backbone of our scenery and when uplifted and eroded into shapes like mountains, arches, mesas, buttes, caves, canyons, and cliffs they become the focal points of parks and scenic overlooks. Other than that, rocks usually don't get much attention except from geologists. Not only do we admire them from afar, we look at them with microscopes, x-rays, and MRI. We crush them, dissolve them, sort them by size, and dye them. We see which parts float in what liquids. The things geologists haven't done to rocks to try and tease out a bit more information probably just haven't been thought of yet.

The rocks that contain fossils are sedimentary rocks. As part of the rock cycle, erosion breaks rocks into particles. These particles are moved around by wind, water, or ice and eventually settle into layers. Each process, blowing wind, still or flowing water, and creeping ice leave traces in the rocks. Wind blown dust is small. The particles are often sharp, angular, and frosted like ground glass. Swiftly flowing water rapidly rounds and polishes particles and sorts them by size. As flowing water slows down, bigger particles settle first followed by smaller ones.

Each environment places its own characteristic mark on rocks. Geologists study many modern environments: beach, estuary, swamp, marsh, reefs, barrier islands, sabkha, tidal channel, river, delta, pond, lake, desert, and more. The conditions that prevail in each environment leave clues in rocks that can be used as analogs to determine how ancient layers were deposited; this is Hutton's "uniformitarianism". The type of rock deposited is often limited by the environment. Most limestones form in relatively shallow, warm tropical seas; they don't indicate arctic conditions. Coal forms in swamps. The rocks on an ocean beach pile up differently than the rocks forming in a delta where a river meets that same ocean.

Fossils also are characteristic of the environments where rocks form. A mixture of fish, shells, and star fish indicate ocean conditions. The tree trunks, branches, and leaves (as in coal) indicate swamps. Some environments don't have many fossils. Creatures that die in open, temperate grass lands are scavenged, scattered, and crushed. Bugs and microbes finish the job breaking down the bones into the soil. In other places, the relentless action of waves grinds any fossils to tiny particles you wouldn't recognize as a fossil, but geologists with a microscope would.

It is the type of rock (limestone, sandstone, shale, and others), the mixture of particle sizes and shapes, the abundance and types of fossils, the marks left by wind, water, and ice (ripples, cross bedding, striae, and more) that all tell stories about how a rock layer came to be. The rock layers are stacked one upon another in somewhat predictable patterns. Rock types formed side-by-side over large distances can often be stacked as well. For example, along the Gulf Coast from New Orleans to Key West several different rock types are being deposited. As these environments shift over time, the places where mud (Mississippi River delta), quartz sand (Destin), and lime sand (Key West) will shift and stack.

The processes responsible for depositing rocks occur at different rates. Floods, storms, landslides, slumps, and earthquakes are all very fast and each can change the rocks being deposited in the course of seconds to weeks. Glaciers, lakes, and rivers are slow, the processes often persisting for thousands of years. Regular daily tides move mud around broad flats (like the Bahamas) but show variations related to spring and neap tides; the deposition of a single layer may be fast (a day), but the environmental conditions may persist for millennia. All of these processes are dynamic, a continuous cycle of eroding and depositing, shifting environments, and drifting continents.

It is the stacking of rock layers that demonstrate the many layers weren't deposited by a single catastrophic flood. The variations of rock layers over time show rocks were deposited by many different processes. In geology, the studies of the environments and processes whereby rocks are deposited and then relating that information to understanding ancient layered rocks are stratigraphy and sedimentology.

Of Fossils and Floods

Fossils are the remains of ancient life preserved in rocks. Fossils may be the hard parts of animals (teeth, skeletons, shells, stems, and the like), impressions (trees, leaves), traces (tracks and trails), and organic chemicals (collagen as in the recent T. Rex study and others). "Fossil" fuels, coal, oil, and natural gas, are the cooked and altered remains of plants and animals.

In the early 1500's, the exact nature of fossils was a topic of much debate. There were several prevailing theories: they were creatures that lived and grew in the rocks; or, they were creatures that had perished in the Biblical flood. Another theory claimed they were marks left in the rock by Satan to vex humanity. Leonardo da Vinci thought a great deal about fossils and between 1506 and 1510 he wrote down his ideas in a manuscript that is now known as the Codex Leicester.¹ Observing that there was a mixture of large and small shells, that they showed growth lines, that there were no nutrients, and the creatures couldn't move around, Leonardo concluded the fossils were once living creatures that had been buried. This left the question of how the fossils came to be on dry land and at the top of mountains.

Leonardo dismissed the notion that fossils originated as a result of a global flood. Leonardo reasoned that if there were a global flood:

1. There would be nowhere for the water to go when it receded.
2. The rocks containing fossils would be a single layer containing a vast and jumbled mixture of shells rather than in the regular steps and layers that characterize the rocks.
3. The torrential rains of a great flood would carry fossils downhill and away from mountaintops and land.

Leonardo described oysters and corals and considered it impossible that a single flood could have carried them 300 miles inland and uphill, nor could they swim or walk there. Leonardo's reasoning was clear and simple. He concluded that fossils were creatures that once lived in the seas and the rocks formed when those seas were somehow lifted up to the mountains. This uplift wasn't adequately until the mid 20th century when Alfred Wegener proposed continental drift which was expanded into the idea of Plate Tectonics.

¹ The Codex Leicester has been scanned, translated, indexed, and produced as a multimedia CD by Corbis. Unfortunately, it is out of print and you may have to look for it at your local library (where I found a copy). Other print editions are also available.

Principles of Geology

Each branch of science is based on fundamental principles. The periodic table in chemistry and conservation of matter and energy in physics are examples. The founding principles of geology are:

1. (Nicholas Steno, 1638-1686) Superposition. In an undisturbed sequence, a rock layer is younger than the layer upon which it rests and older than the rocks that rest on it. Like a brick wall, older rocks (like the first laid bricks) are at the base of a sequence and younger layers (later courses of brick) are on top.
   

2. (Steno) Original horizontality. Sedimentary rocks were originally deposited in nearly flat layers.

3. (Steno) Lateral continuity. Within the limits of a particular environment, similar sequences of rocks from one area can be matched to those in another area: across a valley, extending underground, and even across continents.

4. (James Hutton, 1726-1797) Cross-cutting relations. A fold, fault, or volcanic rock is younger than the rocks it effects.

5. (Hutton) Unconformities. Some boundaries between rock layers represent significant time during which either no rocks were deposited or pre-existing rocks were removed by erosion.

6. (Hutton) Uniformitarianism. The “present is the key to the past” idea. Environments and processes we see shaping the Earth around us today can be used as models for what happened in the past.

7. (William "Strata" Smith, 1769-1839) Faunal succession. The fossils in a rock are unique to that unit. This modern name implies change through time, but succession is a more recent idea than the original concept. Charles Darwin didn't publish Origin of the Species until 20 years after Smith died.

These principles form a set of guidelines for studying rocks. They are not unbreakable laws like the law of gravity, for example. They do, however, establish an orderly way to begin the study of rocks. When a sequence of rocks doesn't conform to these principles, geologists know to look closely and carefully to determine what the story is that the rocks are telling.

Apparent violations of Superposition, like the Lewis Overthrust, for example, are often cited as cause to reject geology and the fossil record. This criticism fails to admit that geologists (and many others): 1) have observed rocks moving in earthquakes; 2) have seen and investigated the structures and marks left in rocks by that movement; and 3) have found those same features in faults and overthrusts that may have moved millions of years ago. Geologists have been able to trace the movement of the rocks over time and match the rocks that moved to their original positions.

Before I leave this subject, a couple of terms should be defined:

1. Fault -- a break in a sequence of rocks along which movement has occurred, the San Andreas Fault for example
2. Fold -- an upward (anticline) or downward (syncline) bending of rocks (occurs after they were formed or deposited)
3. Overthrust -- a type of fault that is nearly flat and where the rocks above the fault have moved a long way relative to the rocks below
   
4. Thrust fault -- a type of fault implying a specific movement of one side of the fault relative to the other

As a geologist, I'm sorely tempted to define such minutiae as hanging wall, foot wall, normal fault, slickensides, recumbent folds, facies, and others, but I hear the patter of patter of dodos approaching.

Faith and Open Minds

Conservative and "fundamentalist" Christians often the criticize the scientific world view for its failure to consider their viewpoint; scientists are closed minded. This critique is incorrect.

Faith is "a belief that does not rest on logical proof or evidence"¹, see Heb 11:1. Faith is thus immune to evidence. No scientific claims made, evidence collected, or logic applied can ever be expected to dissuade someone of their faith-based notions. Faith itself is considered evidence of things not seen. This argument is transparently false; faith that the Sun is a horse-drawn chariot driven across the sky doesn't make it so.

Openminded, on the other hand, is defined as "having or showing a mind receptive to new ideas or arguments".² Science is malleable. As new evidence and ideas are tested and verified, scientists change their minds. Conservative Christians label this provisional nature of science a weakness. It certainly doesn't help that some philosophers question whether an objective reality exists and if anything can be known at all.

In Biblical times, the world's best thinkers knew the Earth was flat and the sky supported by pillars (see for example Job 9:6 and Psalms 75:3). Copernicus, Galileo, Columbus and others demonstrated otherwise. Without their foundation for a spherical earth and a heliocentric solar system, the ability to launch weather, communication, and digital television satellites would be impossible.

Scientists change their mind for good reasons. That doesn't mean they can't fool themselves or be fooled by others. Science, unlike faith, is self-correcting. Self-delusion and fraud will not stand the scrutiny of reasoned testing and evidence.

1. faith. (n.d.). The American Heritage® Dictionary of the English Language, Fourth Edition. Retrieved April 22, 2007, from Dictionary.com website: http://dictionary.reference.com/browse/faith

2. openminded. (n.d.). Dictionary.com Unabridged (v 1.1). Retrieved April 22, 2007, from Dictionary.com website: http://dictionary.reference.com/browse/openminded