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Author Topic: Nothing in Biology Makes Sense Except in the Light of Evolution  (Read 13414 times)
Posts: 1788


« on: May 11, 2012, 05:28:41 PM »

   I think that this article makes some very important points despite the fact that i strongly disagree with the author's statement that evolutionary doctrine does not clash with religious faith.


Nothing in Biology Makes Sense Except in the Light of Evolution

As recently as 1966, sheik Abd el Aziz bin Baz asked the king of Saudi Arabia to suppress a heresy that was spreading in his land. Wrote the sheik:

"The Holy Koran, the Prophet's teachings, the majority of Islamic scientists, and the actual facts all prove that the sun is running in its orbit... and that the earth is fixed and stable, spread out by God for his mankind.... Anyone who professed otherwise would utter a charge of falsehood toward God, the Koran, and the Prophet."

The good sheik evidently holds the Copernican theory to be a "mere theory," not a "fact." In this he is technically correct. A theory can be verified by a mass of facts, but it becomes a proven theory, not a fact. The sheik was perhaps unaware that the Space Age had begun before he asked the king to suppress the Copernican heresy. The sphericity of the earth has been seen by astronauts, and even by many earth-bound people on their television screens. Perhaps the sheik could retort that those who venture beyond the confines of God's earth suffer hallucinations, and that the earth is really flat.

Parts of the Copernican world model, such as the contention that the earth rotates around the sun, and not vice versa, have not been verified by direct observations even to the extent the sphericity of the earth has been. Yet scientists accept the model as an accurate representation of reality. Why? Because it makes sense of a multitude of facts which are otherwise meaningless or extravagant. To non-specialists most of these facts are unfamiliar. Why then do we accept the "mere theory" that the earth is a sphere revolving around a spherical sun? Are we simply submitting to authority? Not quite: we know that those who took the time to study the evidence found it convincing.

The good sheik is probably ignorant of the evidence. Even more likely, he is so hopelessly biased that no amount of evidence would impress him. Anyway, it would be sheer waste of time to attempt to convince him. The Koran and the Bible do not contradict Copernicus, nor does Copernicus contradict them. It is ludicrous to mistake the Bible and the Koran for primers of natural science. They treat of matters even more important: the meaning of man and his relations to God. They are written in poetic symbols that were understandable to people of the age when they were written, as well as to peoples of all other ages. The king of Arabia did not comply with the sheik's demand. He knew that some people fear enlightenment, because enlightenment threatens their vested interests. Education is not to be used to promote obscurantism.

The earth is not the geometric center of the universe, although it may be its spiritual center. It is a mere speck of dust in the cosmic spaces. Contrary to Bishop Ussher's calculations, the world did not appear in approximately its present state in 4004 BC. The estimates of the age of the universe given by modern cosmologists are still only rough approximations, which are revised (usually upward) as the methods of estimation are refined. Some cosmologists take the universe to be about 10 billion years old; others suppose that it may have existed, and will continue to exist, eternally. The origin of life on earth is dated tentatively between 3 and 5 billion years ago; manlike beings appeared relatively quite recently, between 2 and 4 million years ago. The estimates of the age of the earth, of the duration of the geologic and paleontologic eras, and of the antiquity of man's ancestors are now based mainly on radiometric evidence the proportions of isotopes of certain chemical elements in rocks suitable for such studies.

Shiek bin Baz and his like refuse to accept the radiometric evidence, because it is a "mere theory." What is the alternative? One can suppose that the Creator saw fit to play deceitful tricks on geologists and biologists. He carefully arranged to have various rocks provided with isotope ratios just right to mislead us into thinking that certain rocks are 2 billion years old, others 2 million, which in fact they are only some 6,000 years old. This kind of pseudo-explanation is not very new. One of the early anti-evolutionists, P. H. Gosse, published a book entitled Omphalos ("the Navel"). The gist of this amazing book is that Adam, though he had no mother, was created with a navel, and that fossils were placed by the Creator where we find them now -- a deliberate act on His part, to give the appearance of great antiquity and geologic upheavals. It is easy to see the fatal flaw in all such notions. They are blasphemies, accusing God of absurd deceitfulness. This is as revolting as it is uncalled for.

Diversity of Living Beings

The diversity and the unity of life are equally striking and meaningful aspects of the living world. Between 1.5 and 2 million species of animals and plants have been described and studied; the number yet to be described is probably as great. The diversity of sizes, structures, and ways of life is staggering but fascinating. Here are just a few examples.

The foot-and-mouth disease virus is a sphere 8-12 mm in diameter. The blue whale reaches 30 m in length and 135 t in weight. The simplest viruses are parasites in cells of other organisms, reduced to barest essentials minute amounts of DNA or RNA, which subvert the biochemical machinery of the host cells to replicate their genetic information, rather than that of the host.

It is a matter of opinion, or of definition, whether viruses are considered living organisms or peculiar chemical substances. The fact that such differences of opinion can exist is in itself highly significant. It means that the borderline between living and inanimate matter is obliterated. At the opposite end of the simplicity complexity spectrum you have vertebrate animals, including man. The human brain has some 12 billion neurons; the synapses between the neurons are perhaps a thousand times numerous.

Some organisms live in a great variety of environments. Man is at the top of the scale in this respect. He is not only a truly cosmopolitan species but, owing to his technologic achievements, can survive for at least a limited time on the surface of the moon and in cosmic spaces. By contrast, some organisms are amazingly specialized. Perhaps the narrowest ecologic niche of all is that of a species of the fungus family Laboulbeniaceae, which grows exclusively on the rear portion of the elytra of the beetle Aphenops cronei, which is found only in some limestone caves in southern France. Larvae of the fly Psilopa petrolei develop in seepages of crude oil in California oilfields; as far as is known they occur nowhere else. This is the only insect able to live and feed in oil, and its adult can walk on the surface of the oil only as long as no body part other than the tarsi are in contact with the oil. Larvae of the fly Drosophila carciniphila develop only in the nephric grooves beneath the flaps of the third maxilliped of the land crab Geocarcinus ruricola, which is restricted to certain islands in the Caribbean.

Is there an explanation, to make intelligible to reason this colossal diversity of living beings? Whence came these extraordinary, seemingly whimsical and superfluous creatures, like the fungus Laboulbenia, the beetle Aphenops cronei, the flies Psilopa petrolei and Drosophila carciniphila, and many, many more apparent biologic curiosities? The only explanation that makes sense is that the organic diversity has evolved in response to the diversity of environment on the planet earth. No single species, however perfect and however versatile, could exploit all the opportunities for living. Every one of the millions of species has its own way of living and of getting sustenance from the environment. There are doubtless many other possible ways of living as yet unexploited by any existing species; but one thing is clear: with less organic diversity, some opportunities for living would remain unexploited. The evolutionary process tends to fill up the available ecologic niches. It does not do so consciously or deliberately; the relations between evolution and environment are more subtle and more interesting than that. The environment does not impose evolutionary changes on its inhabitants, as postulated by the now abandoned neo-Lamarckian theories. The best way to envisage the situation is as follows: the environment presents challenges to living species, to which the later may respond by adaptive genetic changes.

An unoccupied ecologic niche, an unexploited opportunity for living, is a challenge. So is an environmental change, such as the Ice Age climate giving place to a warmer climate. Natural selection may cause a living species to respond to the challenge by adaptive genetic changes. These changes may enable the species to occupy the formerly empty ecologic niche as a new opportunity for living, or to resist the environmental change if it is unfavorable. But the response may or may not be successful. This depends on many factors, the chief of which is the genetic composition of the responding species at the time the response is called for. Lack of successful response may cause the species to become extinct. The evidence of fossils shows clearly that the eventual end of most evolutionary lines is extinction. Organisms now living are successful descendants of only a minority of the species that lived in the past and of smaller and smaller minorities the farther back you look. Nevertheless, the number of living species has not dwindled; indeed, it has probably grown with time. All this is understandable in the light of evolution theory; but what a senseless operation it would have been, on God's part, to fabricate a multitude of species ex nihilo and then let most of them die out!

There is, of course, nothing conscious or intentional in the action of natural selection. A biologic species does not say to itself, "Let me try tomorrow (or a million years from now) to grow in a different soil, or use a different food, or subsist on a different body part of a different crab." Only a human being could make such conscious decisions. This is why the species Homo sapiens is the apex of evolution. Natural selection is at one and the same time a blind and creative process. Only a creative and blind process could produce, on the one hand, the tremendous biologic success that is the human species and, on the other, forms of adaptedness as narrow and as constraining as those of the overspecialized fungus, beetle, and flies mentioned above.

Anti-evolutionists fail to understand how natural selection operates. They fancy that all existing species were generated by supernatural fiat a few thousand years ago, pretty much as we find them today. But what is the sense of having as many as 2 or 3 million species living on earth? If natural selection is the main factor that brings evolution about, any number of species is understandable: natural selection does not work according to a foreordained plan, and species are produced not because they are needed for some purpose but simply because there is an environmental opportunity and genetic wherewithal to make them possible. Was the Creator in a jocular mood when he made Psilopa petrolei for California oil fields and species of Drosophila to live exclusively on some body-parts of certain land crabs on only certain islands in the Caribbean? The organic diversity becomes, however, reasonable and understandable if the Creator has created the living world not by caprice but by evolution propelled by natural selection. It is wrong to hold creation and evolution as mutually exclusive alternatives. I am a creationist and an evolutionist. Evolution is God's, or Nature's method of creation. Creation is not an event that happened in 4004 BC; it is a process that began some 10 billion years ago and is still under way.

Unity of Life

The unity of life is no less remarkable than its diversity. Most forms of life are similar in many respects. The universal biologic similarities are particularly striking in the biochemical dimension. From viruses to man, heredity is coded in just two, chemically related substances: DNA and RNA. The genetic code is as simple as it is universal. There are only four genetic "letters" in DNA: adenine, guanine, thymine, and cytosine. Uracil replaces thymine in RNA. The entire evolutionary development of the living world has taken place not by invention of new "letters" in the genetic "alphabet" but by elaboration of ever-new combinations of these letters.

Not only is the DNA-RNA genetic code universal, but so is the method of translation of the sequences of the "letters" in DNA-RNA into sequences of amino acids in proteins. The same 20 amino acids compose countless different proteins in all, or at least in most, organisms. Different amino acids are coded by one to six nucleotide triplets in DNA and RNA. And the biochemical universals extend beyond the genetic code and its translation into proteins: striking uniformities prevail in the cellular metabolism of the most diverse living beings. Adenosine triphosphate, biotin, riboflavin, hemes, pyridoxin, vitamins K and B12, and folic acid implement metabolic processes everywhere.

What do these biochemical or biologic universals mean? They suggest that life arose from inanimate matter only once and that all organisms, no matter now diverse, in other respects, conserve the basic features of the primordial life. (It is also possible that there were several, or even many, origins of life; if so, the progeny of only one of them has survived and inherited the earth.) But what if there was no evolution and every one of the millions of species were created by separate fiat? However offensive the notion may be to religious feeling and to reason, the anti-evolutionists must again accuse the Creator of cheating. They must insist that He deliberately arranged things exactly as if his method of creation was evolution, intentionally to mislead sincere seekers of truth.

The remarkable advances of molecular biology in recent years have made it possible to understand how it is that diverse organisms are constructed from such monotonously similar materials: proteins composed of only 20 kinds of amino acids and coded only by DNA and RNA, each with only four kinds of nucleotides. The method is astonishingly simple. All English words, sentences, chapters, and books are made up of sequences of 26 letters of the alphabet. (They can be represented also by only three signs of the Morse code: dot, dash, and gap.) The meaning of a word or a sentence is defined not so much by what letters it contains as by the sequences of these letters. It is the same with heredity: it is coded by the sequences of the genetic "letters" the nucleotides in the DNA. They are translated into the sequences of amino acids in the proteins.

Full article: http://www.pbs.org/wgbh/evolution/library/10/2/text_pop/l_102_01.html
Iniko Ujaama
Posts: 541

« Reply #1 on: July 21, 2012, 09:25:05 AM »

Interview with Lynn Margulis, author of Symbiotic Planet: A New Look at Evolution

Living World / Evolution: Discover Interview Lynn Margulis Says She's Not Controversial, She's Right

A conversation with Lynn Margulis is an effective way to change the way you think about life. Not just your life. All life. Scientists today recognize five groups of life: bacteria, protoctists (amoebas, seaweed), fungi (yeast, mold, mushrooms), plants, and animals. Margulis, a self-described “evolutionist,” makes a convincing case that there are really just two groups, bacteria and everything else.
That distinction led to her career-making insight. In a 1967 paper published in the Journal of Theoretical Biology, Margulis suggested that mitochondria and plastids—vital structures within animal and plant cells—evolved from bacteria hundreds of million of years ago, after bacterial cells started to collect in interactive communities and live symbiotically with one another. The resulting mergers yielded the compound cells known as eukaryotes, which in turn gave rise to all the rest—the protoctists, fungi, plants, and animals, including humans. The notion that we are all the children of bacteria seemed outlandish at the time, but it is now widely supported and accepted. “The evolution of the eukaryotic cells was the single most important event in the history of the organic world,” said Ernst Mayr, the leading evolutionary biologist of the last century. “Margulis’s contribution to our understanding the symbiotic factors was of enormous importance.”
Her subsequent ideas remain decidedly more controversial. Margulis came to view symbiosis as the central force behind the evolution of new species, an idea that has been dismissed by modern biologists. The dominant theory of evolution (often called neo-Darwinism) holds that new species arise through the gradual accumulation of random mutations, which are either favored or weeded out by natural selection. To Margulis, random mutation and natural selection are just cogs in the gears of evolution; the big leaps forward result from mergers between different kinds of organisms, what she calls symbiogenesis. Viewing life as one giant network of social connections has set Margulis against the mainstream in other high-profile ways as well. She disputes the current medical understanding of AIDS and considers every kind of life to be “conscious” in a sense.

Margulis herself is a highly social organism. Now 71, she is a well-known sight at the University of Massachusetts at Amherst, where she is on the geosciences faculty, riding her bike in all weather and at all times of day. Interviewer Dick Teresi, a neighbor, almost ran her over when, dressed in a dark coat, she cycled in front of his car late at night. On the three occasions that they met for this interview, Teresi couldn’t help noticing that Margulis shared her home with numerous others: family, students, visiting scholars, friends, friends of friends, and anybody interesting who needed a place to stay.
Most scientists would say there is no controversy over evolution. Why do you disagree?

All scientists agree that evolution has occurred—that all life comes from a common ancestry, that there has been extinction, and that new taxa, new biological groups, have arisen. The question is, is natural selection enough to explain evolution? Is it the driver of evolution?
And you don’t believe that natural selection is the answer?

This is the issue I have with neo-Darwinists: They teach that what is generating novelty is the accumulation of random mutations in DNA, in a direction set by natural selection. If you want bigger eggs, you keep selecting the hens that are laying the biggest eggs, and you get bigger and bigger eggs. But you also get hens with defective feathers and wobbly legs. Natural selection eliminates and maybe maintains, but it doesn’t create.
That seems like a fairly basic objection. How, then, do you think the neo-Darwinist perspective became so entrenched?

In the first half of the 20th century, neo-Darwinism became the name for the people who reconciled the type of gradual evolutionary change described by Charles Darwin with Gregor Mendel’s rules of heredity [which first gained widespread recognition around 1900], in which fixed traits are passed from one generation to the next. The problem was that the laws of genetics showed stasis, not change. If you have pure breeding red flowers and pure breeding white flowers, like carnations, you cross them and you get pink flowers. You back-cross them to the red parent and you could get three-quarters red, one-quarter white. Mendel showed that the grandparent flowers and the offspring flowers could be identical to each other. There was no change through time.
There’s no doubt that Mendel was correct. But Darwinism says that there has been change through time, since all life comes from a common ancestor—something that appeared to be supported when, early in the 20th century, scientists discovered that X-rays and specific chemicals caused mutations. But did the neo-
Darwinists ever go out of their offices? Did they or their modern followers, the population geneticists, ever go look at what’s happening in nature the way Darwin did? Darwin was a fine naturalist. If you really want to study evolution, you’ve got go outside sometime, because you’ll see symbiosis everywhere!
So did Mendel miss something? Was Darwin wrong?

I’d say both are incomplete. The traits that follow Mendel’s laws are trivial. Do you have a widow’s peak or a straight hairline? Do you have hanging earlobes or attached earlobes? Are you female or male? Mendel found seven traits that followed his laws exactly. But neo-Darwinists say that new species emerge when mutations occur and modify an organism. I was taught over and over again that the accumulation of random mutations led to evolutionary change—led to new species. I believed it until I looked for evidence.
What kind of evidence turned you against neo-Darwinism?

What you’d like to see is a good case for gradual change from one species to another in the field, in the laboratory, or in the fossil record—and preferably in all three. Darwin’s big mystery was why there was no record at all before a specific point [dated to 542 million years ago by modern researchers], and then all of a sudden in the fossil record you get nearly all the major types of animals. The paleontologists Niles Eldredge and Stephen Jay Gould studied lakes in East Africa and on Caribbean islands looking for Darwin’s gradual change from one species of trilobite or snail to another. What they found was lots of back-and-forth variation in the population and then—whoop—a whole new species. There is no gradualism in the fossil record.
Gould used the term “punctuated equilibrium” to describe what he interpreted as actual leaps in evolutionary change. Most biologists disagreed, suggesting a wealth of missing fossil evidence yet to be found. Where do you stand in the debate?

“Punctuated equilibrium” was invented to describe the discontinuity in the appearance of new species, and symbiogenesis supports the idea that these discontinuities are real. An example: Most clams live in deep, fairly dark waters. Among one group of clams is a species whose ancestors ingested algae—a typical food—but failed to digest them and kept the algae under their shells. The shell, with time, became translucent, allowing sunlight in. The clams fed off their captive algae and their habitat expanded into sunlit waters. So there’s a discontinuity between the dark-dwelling, food-gathering ancestor and the descendants that feed themselves photosynthetically


Then later in the interview....

What about the famous “beak of the finch” evolutionary studies of the 1970s? Didn’t they vindicate Darwin?

Peter and Rosemary Grant, two married evolutionary biologists, said, ‘To hell with all this theory; we want to get there and look at speciation happening.’ They measured the eggs, beaks, et cetera, of finches on Daphne Island, a small, hilly former volcano top in Ecuador’s Galápagos, year after year. They found that during floods or other times when there are no big seeds, the birds with big beaks can’t eat. The birds die of starvation and go extinct on that island.
Did the Grants document the emergence of new species?

They saw this big shift: the large-beaked birds going extinct, the small-beaked ones spreading all over the island and being selected for the kinds of seeds they eat. They saw lots of variation within a species, changes over time. But they never found any new species—ever. They would say that if they waited long enough they’d find a new species.
Some of your criticisms of natural selection sound a lot like those of Michael Behe, one of the most famous proponents of “intelligent design,” and yet you have debated Behe. What is the difference between your views?

The critics, including the creationist critics, are right about their criticism. It’s just that they’ve got nothing to offer but intelligent design or “God did it.” They have no alternatives that are scientific.


In contrast, the symbiotic view of evolution has a long lineage in Russia, right?

From the very beginning the Russians said natural selection was a process of elimination and could not produce all the diversity we see. They understood that symbiogenesis was a major source of innovation, and they rejected Darwin. If the English-speaking world owns natural selection, the Russians own symbiogenesis. In 1924, this man Boris Mikhaylovich Kozo-Polyansky wrote a book called Symbiogenesis: A New Principle of Evolution, in which he reconciled Darwin’s natural selection as the eliminator and symbiogenesis as the innovator. Kozo-Polyansky looked at cilia—the wavy hairs that some microbes use to move—and said it is not beyond the realm of possibility that cilia, the tails of sperm cells, came from “flagellated cytodes,” by which he clearly meant swimming bacteria.
Has that idea ever been verified?

The sense organs of vertebrates have modified cilia: The rods and cone cells of the eye have cilia, and the balance organ in the inner ear is lined with sensory cilia. You tilt your head to one side and little calcium carbonate stones in your inner ear hit the cilia. This has been known since shortly after electron microscopy came in 1963. Sensory cilia did not come from random mutations. They came by acquiring a whole genome of a symbiotic bacterium that could already sense light or motion. Specifically, I think it was a spirochete [a corkscrew-shaped bacterium] that became the cilium.

Don’t spirochetes cause syphilis?

Yes, and Lyme disease. There are many kinds of spirochetes, and if I’m right, some of them are ancestors to the cilia in our cells. Spirochete bacteria are already optimized for sensitivity to motion, light, and chemicals. All eukaryotic cells have an internal transport system. If I’m right, the whole system—called the cytoskeletal system—came from the incorporation of ancestral spirochetes. Mitosis, or cell division, is a kind of internal motility system that came from these free-living, symbiotic, swimming bacteria. Here [she shows a video] we compare isolated swimming sperm tails to free-swimming spirochetes. Is that clear enough?
And yet these ideas are not generally accepted. Why?

Do you want to believe that your sperm tails come from some spirochetes? Most men, most evolutionary biologists, don’t. When they understand what I’m saying, they don’t like it.

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