I WISH that I had written the below, I did not. Please feel free to discuss., and for the record, I do agree in the absolute with the below, but pay me not the compliment as to assume my authorship. The bottom half is WIKIPEDIA, the top half with the colours (I did that, pretty eh?) was written by ChunkyDiaperJesus, whoever they may be–a good thinker/writer for sure.
“We live, we are constantly told, in a scientific age. We look to science to help us achieve the good life, to solve our problems (especially our medical aches and pains), and to tell us about the world. A great deal of our education system, particularly the post-secondary curriculum, is organized as science or social science. And yet, curiously enough, there is one major scientific truth which vast numbers of people refuse to accept (by some news accounts a majority of people in North America)–the fact of evolution. Yet it is as plain as plain can be that the scientific truth of evolution is so overwhelmingly established, that it is virtually impossible to refute within the bounds of reason. No major scientific truth, in fact, is easier to present, explain, and defend.
Before demonstrating this claim, let me make it clear what I mean by evolution, since there often is some confusion about the term. By evolution I mean, very simply, the development of animal and plant species out of other species not at all like them, for example, the process by which, say, a species of fish gets transformed (or evolves) through various stages into a cow, a kangaroo, or an eagle. This definition, it should be noted, makes no claims about how the process might occur, and thus it certainly does not equate the concept of evolution with Darwinian Natural Selection, as so many people seem to do. It simply defines the term by its effects (not by how those effects are produced, which could well be the subject of another argument).
The first step in demonstrating the truth of evolution is to make the claim that all living creatures must have a living parent. This point has been overwhelmingly established in the past century and a half, ever since the French scientist Louis Pasteur demonstrated how fermentation took place and thus laid to rest centuries of stories about beetles arising spontaneously out of dung or gut worms being miraculously produced from non-living material. There is absolutely no evidence for this ancient belief. Living creatures must come from other living creatures. This is called Biogenisis. It does no damage to this point to claim that life must have had some origin way back in time; this is referred to as Abiogenisis, perhaps in a chemical reaction of inorganic materials (in some primordial soup) or in some invasion from outer space. A highly probable theory is that life sprang into existence billions of times before one organism had the ability to reproduce and divide. That may well be true. But what is clear is that any such origin for living things or living material must result in a very simple organism. There is no evidence whatsoever (except in science fiction like Frankenstein) that inorganic chemical processes can produce complex, multi-cellular living creatures (the recent experiments cloning sheep, of course, are based on living tissue from other sheep).
The second important point in the case for evolution is that some living creatures are very different from some others. This, I take it, is self-evident. Let me cite a common example: many animals have what we call an internal skeletal structure featuring a backbone and skull. We call these animals vertebrates. Most animals do not have these features (we call them invertebrates). The distinction between vertebrates and invertebrates is something no one who cares to look at samples of both can reasonably deny, and, so far as I am aware, no one hostile to evolution has ever denied a fact so apparent to anyone who observes the world for a few moments.
The final point in the case for evolution is this: simple animals and plants existed on earth long before more complex ones (invertebrate animals, for example, were around for a very long time before there were any vertebrates). Here again, the evidence from fossils is overwhelming. In the deepest rock layers, there are no signs of life. The first fossil remains are of very simple living things. As the strata get more recent, the variety and complexity of life increase (although not at a uniform rate). And no human fossils have ever been found except in the most superficial layers of the earth (e.g., battlefields, graveyards, flood deposits, and so on). In all the countless geological excavations and inspections (for example, of the Grand Canyon), no one has ever come up with a genuine fossil remnant which goes against this general principle (and it would only take one genuine find to overturn this principle).
Well, if we put these three points together, the rational case for evolution is air tight. If all living creatures must have a living parent, if living creatures are different, and if simpler forms were around before the more complex forms, then the more complex forms must have come from the simpler forms (e.g., vertebrates from invertebrates). There is simply no other way of dealing reasonably with the evidence we have. Of course, one might deny (as some do) that the layers of the earth represent a succession of very lengthy epochs and claim, for example, that the Grand Canyon was created in a matter of days, but this CONCLUSIVELY violates scientific observation and all known scientific processes as much as does the claim that, say, vertebrates just, well, appeared one day out of a spontaneous combination of chemicals.
To make the claim for the scientific truth of evolution in this way is to assert nothing about how it might occur. Darwin provided one answer (through natural selection). The above argument is intended, however, to demonstrate that the general principle of evolution is, given the scientific evidence, logically unassailable and that, thus, the concept is a law of nature as truly established as is, say, gravitation. The theory of evolution and the theory of gravity are both SCIENTIFIC THEORIES. Scientific theories are not your every-day “I got an idea” theories. These have been studied, tested, experimented, and are now accepted as NATURAL LAW. That scientific certainty makes the widespread rejection of evolution in our modern age something of a puzzle (but that’s a subject for another essay). In a modern liberal democracy, of course, one is perfectly free to reject that conclusion, but one is not legitimately able to claim that such a rejection is a reasonable scientific stance. Science doesn’t tell us what we WANT to hear. It tells us what is real, observable, and testable. And it has yet to tell us anything about a creator.“
Law of superposition
The law of superposition (or the principle of superposition) is a key axiom based on observations of natural history that is a foundational principle of sedimentary stratigraphy and so of other geology dependent natural sciences:
“ Sedimentary layers are deposited in a time sequence, with the oldest on the bottom and the youngest on the top. ”
The principle was first proposed in the 11th century by the Persian geologist, Avicenna (Ibn Sina), and the law was later formulated more clearly in the 17th century by the Danish scientist Nicolas Steno.
Development of the Law of Superposition
While discussing the origins of mountains in The Book of Healing in 1027, Avicenna first outlined the principle of the superposition of strata as follows:
“ It is also possible that the sea may have happened to flow little by little over the land consisting of both plain and mountain, and then have ebbed away from it. … It is possible that each time the land was exposed by the ebbing of the sea a layer was left, since we see that some mountains appear to have been piled up layer by layer, and it is therefore likely that the clay from which they were formed was itself at one time arranged in layers. One layer was formed first, then at a different period, a further was formed and piled, upon the first, and so on. Over each layer there spread a substance of different material, which formed a partition between it and the next layer; but when petrification took place something occurred to the partition which caused it to break up and disintegrate from between the layers (possibly referring to unconformity). … As to the beginning of the sea, its clay is either sedimentary or primeval, the latter not being sedimentary. It is probable that the sedimentary clay was formed by the disintegration of the strata of mountains. Such is the formation of mountains. ”
Assuming that all rocks and minerals had once been fluid, Nicolas Steno reasoned that rock strata were formed when particles in a fluid such as water fell to the bottom. This process would leave horizontal layers. Thus Steno’s principle of original horizontality states that rock layers form in the horizontal position, and any deviations from this horizontal position are due to the rocks being disturbed later.
There are exceptions to this case, because sediments may be deposited on slopes or gradients. These may be steep, locally, and can be up to several degrees. Nevertheless, the principle is essentially true.
Steno stated another, more general principle in this way:
“ If a solid body is enclosed on all sides by another solid body, of the two bodies that one first became hard which, in the mutual contact, expresses on its own surface the properties of the other surface. ”
In other words: a solid object will cause any solids that form around it later to conform to its own shape.
Steno was able to show by this reasoning that fossils and crystals must have solidified before the host rock that contains them was formed. If a “tongue stone” had grown within a rock, it would have been distorted by the surrounding rock, in much the same way that a tree root is distorted by growing into a crack in the earth. Instead, the “tongue stone” must have been buried in soft sediments which hardened later. Veins (mineral-filled cracks) and many crystals, on the other hand, must have formed after the surrounding rock was a solid, because they often did show irregularities of form caused by having to conform to the surrounding solid rock.
Finally, in the case of strata, layers on top of a set of strata conform to the shape of lower layers. . . and therefore, in a set of strata, the youngest layers must be those of the top layer, and the oldest must lie on the bottom. This is because the youngest layer was deposited after the oldest layers, which determines their place in the layers. Since the oldest was deposited first it is on the bottom and vice versa.
From Steno’s observation that rock strata form when particles fall out of suspension in a fluid, it then follows that the youngest stratum is on the top of a sequence. However, this principle also applies to other types of rocks that do not form with water, such as volcanic rocks which spread on older flows, by flow banding.
Steno realized that other geological processes could create apparent exceptions to his laws of superposition and horizontality . He reasoned that the formation of caves might remove part of a lower layer, and that the collapse of a cave might transport large pieces of an upper layer downwards. He recognized that rocks might be uplifted by subterranean forces. Geologists now recognize that tilting, folding, and faulting may also complicate the analysis of a stratigraphic sequence. Molten rock may force its way through surrounding rocks and may sometimes squeeze between older rock layers, also forming an exception to Steno’s law. However, such anomalies leave physical evidence in the disturbed rocks; for example, faulted rock layers may be cracked, broken, or metamorphosed along the fault lines.
Steno’s law is a statement of relative time, not absolute time: two rock layers, in principle, could form millions of years apart, or days apart.
Application of the law of superposition
Steno himself saw no difficulty in attributing the formation of most rocks to the flood mentioned in the Bible. However, he noticed that, of the two major rock types in the Apennine Mountains near Florence, Italy, the lower layers had no fossils, while the upper ones were rich in fossils. He suggested that the upper layers had formed in the flood, after the creation of life, while the lower ones had formed before life had existed. This was the first use of geology to try to distinguish different time periods in the Earth’s history – an approach that would develop spectacularly in the work of later scientists.
Thrust faults were unknown to Steno and his contemporaries and were not described until the late 19th Century and early 20th century by Peach and Horne at Knockan Crag, Scotland, on the Moine Thrust Fault. Thrust faults can cause confusion with the Law of Superposition because they occur parallel to bedding and can be difficult to detect, thus creating situations where inexplicably, older strata can overlay younger.
When combined with the related principle of faunal succession, the law of superposition provides a very powerful tool for dating rocks and strata.
Superposition as modified by archaeological considerations
Superposition in archaeology and especially in stratification use during excavation is slightly different as the processes involved in laying down archaeological strata are somewhat different from geological processes. Man made intrusions and activity in the archaeological record need not form chronologically from top to bottom or be deformed from the horizontal as natural strata are by equivalent processes. Some archaeological strata (often termed as contexts or layers) are created by undercutting previous strata. An example would be that the silt backfill of an underground drain would form some time after the ground immediately above it. Other examples of non vertical superposition would be modifications to standing structures such as the creation of new doors and windows in a wall. Superposition in archaeology requires a degree of interpretation to correctly identify chronological sequences and in this sense superposition in archaeology is more dynamic and multi- dimensional.
From Wikipedia, the free encyclopedia
Atheists can be said to have a sand layered bottle with the layers intact, while theists have bottles with the sand all mixed up. –rudhro