When I started this blog, my goal was to provide support for the theory of evolution by demonstrating that, contrary to statements by anti-evolutionists, new evidence of evolution is continually being reported. This includes new findings from fields such as cell biology, ecology, morphology (the study of the forms organisms take), ethology (the study of animal behavior), medicine, and neurology. Oh, and let's not forget fossils, which continue to turn up new examples of intermediate forms. Time has not allowed me to carry through with this agenda.


But there is an argument that needs to be made that relates to the question of evidence and evolution. Anti-evolutionists, who with a few exceptions are not biological scientists, claim that current text books and biology curiculla need to reflect an alleged abundance of evidence that calls evolution into serious question. Now this "evidence" has been refuted by competent scientists, but the idea that such evidence could exist is refuted by a proper understanding of the way science works.


If the evidence existed which seriously challenges evolution, and if biological science is operating by the same rules as other sciences, then it would be leading biological scientists who would be insisting on debate about the validity of the theory. Scientists make their mark on the history of science by seeking out such evidence as cannot be explained with current theories. That is what science does. Yet no such fight is being fought, at least not by scientists.


A good example of how this works can be seen in the history of phyics around the turn of the 20th Century. A famous anecdote illustrates the attitude of established physicists at this time. A recent college graduate asked a physics professor if he recommended a student seek an advanced degree in physics. The professor discouraged the student, saying that all the important theories had been established and the only work that remained for physicists was to calculate the known constants to greater and greater accuracy. One student at the time, who thankfully did not receive and follow that advice, was Albert Einstein. In 1905, working as a patent clerk, published papers that exploded the complancy of physicists and established whole new fields of study, such as relativity and quantum mechanics.


How did the scientists of the day respond? Did they ignore this evidence, attempt to cover it up, try to stiffle criticism of the established theories? No. Physicists were energized and zestfully set to work to find the theory that would explain the evidence coming to light better than the established theories. This is not to say that every physicist of the day was persuaded that new theories were needed. In some ways, the new theories did not really take off until the old theorists died off and were replaced by students who did not have any emotional stake in maintaining the status quo.


This is how the system is supposed to work. Science invites the reporting of evidence that calls theories into question. It thrives on them. If the new theories proposed by physicists such as Einstein, Bohr, Heisenberg, and others did not explain the evidence in hand better than the established theories, no changes would have been made. Science is inately conservative, requiring a lot of evidence before changing its collective mind.


My point is that if the evidence that seriously challenged evolution existed, we would not need non-scientists to lead the charge to change the acceptance of evolution in the scientific community or the lay community. The scientists themselves would be fighting over whose theories would replace evolution. No such fight has ever occured in the case of evolution. Most of the evidence that seemed to call evolution into question has turned out to be improperly interpreted. Sometimes later discoveries shed new light on the evidence.

For example, some anti-evolutionists have made much of a bed of rock with fossil footprints that appeared to show footprints of humans along-side footprints of dinosaurs. If this were good evidence, it would indeed throw the field of evolution into a dither; according to orthodox evolution theory dinosaurs were extinct long before primates, much less humans, had evolved. But the evidence was being misinterpreted. A closer examination of the footprints by qualified paleontologists demonstrated that what appeared to be human footprints were prints of a dinosaur which left prints which, at first glance appeared human.


Likewise, anti-evolutionists have insisted that a complex structure like an eye could not evolve because it does not work if any part did not do its job. But scientists have shown that a wide range of organisms have eyes ranging in simplicity from mere light sensitive spots to the eyeball with a lens. Each is but a small change from a simpler example, demonstrating that evolution can produce complex structures.


These attempts to discredit evolution are dead-ends that evolutionary biologists have already considered and rejected, not because they don't want to see the theory discredited, but because evidence supports the conclusions. If this is not yet convincing you, let me give you an analogy that might clarify it.


There are some who claim that the Nazi holocaust of Jews and others undesirables never happened. Knowledgable historians do not discuss these claims, citing this as an alternative interpretation of the evidence, nor are these theories taught in history classes. This is because the evidence for the Holocaust is so extensive that it would be irrational to claim it never happened. Historians don't consider the Holocaust a theory which deserves to be viewed as inconclusive because the evidence is so extensive and so clear that no qualifiers need be made. The Holocaust, unfortunately, happened; it is a fact of history, not a theory.


If we consider what could cause people to question the Holocaust, we cannot but conclude that they choose to believe this in spite of the evidence based on bigotry, not evidence. In a like manner, I conclude that those who believe in intelligent design and creationism do so in spite of the massive weight of evidence based on religious beliefs. To suggest that such ideas have a place in science class is as irrational as to assert that anti-Holocaust texts be introduced in history classes. The only reason to even mention these topics in science or history classes would be to demonstrate antithesis of science and history.

Elephants, Humpbacks, and Humans

In my previous post, I suggested that a number of other species demonstrate many similar traits as humans, suggesting near human intelligence. These traits include the ability to use language, create tools, and interact in complex social hierarchies. Recently, elephants were added to the list of creatures thought to be able to recognize their reflections as an image of themselves, rather than another animal. Self-consciousness suggests an ability to have mental concepts, including an idea of a self. This has also been observed in chimpanzees, bonobos and orangutans, and humans (by two years of age).

Another recent discovery notes similar types of brain cells in humpback whales and humans, of a sort that may relate to intelligence. These types of cells are not found in dolphins, but are found in other primates.

One of the reasons many reject evolution is that they don't want to accept that humans are not special. These people like the idea, promoted by certain religions, that humans were a special creation of God, and that everything in the universe is essentially an elaborate stage. God's attention is focused on us and us alone. This notion has also gone farther, with certain ethnic and cultural groups believing that God does not even favor all humans equally, but gave special information to one tribe of people and no one else. This kind of elitism is betrayed for what it is, pride, when we objectively look at the world. There are many cultures, many religions, and there is beauty and worth in each of these religions, even if none is completely right about everything. Likewise, there are other creatures that differ from us by very little.

It is likely that humans could only achieve our current situation because, in addition to our intelligence, we walked upright, had hands that could make tools, and vocal cords that could make a great variety of sounds. And, as noted in other posts, it is very unlikely that we are the only planet in the universe with intelligent life.

The following very short article relates to the development of planets around stars, about which I made a post some time ago. I'll quote the whole article, which appeared on globeandmail.com.

Planets really made from dust
Globe and Mail Update
Monday, October 09, 2006

Floating discs of debris do indeed turn into planets, and now the world finally has evidence to prove it.
Scientists analyzing data from the Hubble Space Telescope have at last confirmed the long-held belief put forward by philosopher Emmanuel Kant more than 200 years ago.
Until now, astronomers have detected more than 200 extra-solar planets and have seen many debris disks around young stars, but they have yet to observe a planet and a debris disk around the same star.

Again, this does not relate directly to biological evolution, but it shows that the universe incorporates evolution even in its non-biological history. This is a different meaning of evolution from the evolution referred to in natural selection. This is the more general notion that relates to things which change progressively over time and don't change back.

The idea that planets can form from space dust has been around for a while, as the article notes. Over time, more and more evidence has been produced and this process continues. Now we can safely assert that there are hundreds of billions of hundreds of billions of stars in the universe, and many, if not most, of these have planets around them.

The number I gave above is not just hyperbole of the sort associated with Carl Sagan. The accepted round number for stars in our galaxy is 100 billion. And an all sky survey that counted galaxies reached a similar number of galaxies in the universe. Some of these are smaller than the Milky Way but many are much larger. So a hundred billion hundred billion is accurate, to a few orders of magnitude.

We cannot yet determine if any of these other planets has life of any sort, let alone complex, possibly intelligent, organisms. But if we accept that the universe is a well-ordered place, with the same laws operating here as anywhere else, we can only conclude that there should be a great number of planets with life. Considering the number of animals on earth which have similar intelligence and social lives as humans (apes, dolphins, whales, and elephants), I think it very unlikely that we are the only species in the universe contemplating these same questions.

A recent search for articles and papers providing evidence for evolution turned up a wide variety of examples.

Evolution of typhoid bacteria
This is fairly technical and I'm not qualified to sumarize it or elaborate on the evidence, but the opening summary reads as follows:

In a study published in the latest issue of Science (24 November, 2006), an international consortium from the Max-Planck Society, Wellcome Trust Institutes in Britain and Vietnam, and the Institut Pasteur in France have elucidated the
evolutionary history of Salmonella Typhi. Typhi is the cause of typhoid fever, a disease that sickens 21 million people and kills 200,000 worldwide every year. The results indicate that asymptomatic carriers played an essential role in the evolution and global transmission of Typhi.

Clearly, these biologists have no difficulty understanding this disease in terms of evolution, and we are fortunate for this, as they are working to keep us one step ahead of diseases that clearly demonstrate a propensity to evolve. This is a growing problem in hospitals, since strains of bacteria are evolving that are not killed by standard antibiotics.

Oysters in bay adapting to illness

This article opens, "Virginia scientists are finding pockets of oysters in the Chesapeake Bay that have adapted to genetically resist the deadly diseases that threaten the broader population. 'We have what appears to be an evolution of disease-resistant oysters,' said Ryan Carnegie, an assistant research scientist at the Virginia Institute of Marine Science." This shows the other side of the "arms race" between bacteria and the organisms they infect. Some have even suggested that this to some extent accounts for continuing evolution rather than a steady-state situation in which all organisms have evolved to some peak level of survival ability.

Wheat's lost gene helps nutrition

Domesticated varieties of wheat have a gene that normally is not turned on. That is, the gene is present, but another gene is needed to turn it on, so that it acts on the development of the plant. By figuring out a way to turn this gene on, scientists have increased the nutritional quality and decreased the time to reach maturity. For those worried about eating genetically modified foods, the scientists have found a way to turn the gene on by cross-breeding domestic and wild strains of wheat. This may help improve the nutrition for people all over the world. These kinds of advances can never be provided by "intelligent design" theory. How would you predict something like this if you had no way to fathom the designs created by this intelligent designer?

New Gene Map Reveals Surprising Differences

This article reports on a new way of comparing gene maps that picks up on subtle differences from individual to individual in something called 'copy number variants' or CNPs. This may be a revolutionary development because it may enable scientists to identify genetic causes of certain diseases. This says to me that the genetic reproduction process is very complex and so there can be lots of variation before something becomes significant enough to cause an evolutionary change.

Evolution can happen quickly, study finds

I'll quote the first few paragraphs, since they say better than I many important points about evolution and how new research is confirming the theory, rather than challenging it.

A new study of lizards in the Bahamas shows that the natural selection pressures that drive evolution can flip-flop faster than previously thought -- even in months.

"Darwin was right about so many things," said Jonathan Losos, a former Washington University biologist who led the study. "In this case he was wrong. He thought that evolution must occur slowly and gradually."

The lizards and their changing leg lengths are yet another case of evolution occurring in real time. From finches that evolve longer beaks in a few years to bacteria that adapt to strange feeding regimens in days, evolution, as a science, has leapt out of musty museums and into the field. Scientists say that, from a political perspective, the cases offer a vivid reminder of the continuous process that some people imagine proceeding only in fossilized fits and starts: first monkey, then man.

The article goes on to describe science at work, testing hypotheses, improving theories. Scientists measured leg length of a lizard on various islands in the Bahamas. Then they introduced a predator and used evolution to predict how the lizards' legs would change in response. They thought the legs would grow longer initially, since the longer legs would allow the normally ground-dwelling lizards better chances to survive by running up trees. Once the population had lived in the trees a while, however, they expected leg length to decrease again, as it provides a better way to get around in the trees. They found the predicted changes.

For another example of how scientists are testing and verifying evolution, see the next article.

Robot Tadpole Sex Sheds Light on Vertebrate Evolution

Quoting the first few paragraphs:

The distant forebears of humans and other vertebrates were much squashier than their descendants. They possessed flexible rods known as notochords that served as primitive backbones, but no vertebrae. Scientists think vertebrae evolved to
help our ancient predecessors swim more powerfully by stiffening the body so attached muscles could generate more force.

"The fossil record shows vertebrae evolved independently at least four separate times. That shows they must really be functionally important," said vertebrate physiologist John Long at Vassar College in Poughkeepsie, N.Y.

To test this idea, Long and his colleagues built robot fish with backbones of varying strength to simulate extinct animals. They then "mated" the best swimmers to see how generations of "offspring" evolved to swim better.

Here again, a test of the idea of evolution, with no guarantee that the results would confirm the hypothesis. This is a physical version of something that is often done on computers, creating "genetic algorithms." It demonstrated that the hypothesis was confirmed. The faster swimmers, when "mated," (that is when "computer simulations that modeled the genetic mixing that occurs during sex to produce the next generation" were used to generate new designs for the swimmers), produced a structure that does stiffen the region down the center where the spinal cord would be in primative organisms.

But they also found that the hypothesized evolution only accounted for 40% of the improved swimming speed. Evolution found other ways which the scientists had not thought of to improve the "design" of the model. They plan to introduce a robot predator to test how well visual sensing device similar to something in fish can improve through evolution.

Evolution of Complex Organs

One of the most common attacks on evolution is to assert that complex organs such as the eye could not evolve since they only work when all parts are present. National Geographic, obviously intent on showing that this claim is false, has published an article in the November 2006 issue detailing the wealth of evidence for how such organs evolve. For the Internet version of the article, see http://www7.nationalgeographic.com/ngm/0611/feature4/.

The jist of the article is that marvels such as the eye, the arm, feathers, and flowers are, in fact, built up from primative beginnings through minute changes that over millions of years add up to the organ in question. Furthermore, the same genes are used in different organisms to develop different forms of an organ or limb. For example, "Insects and humans use the same genes to tell cells in their embryos to turn into photoreceptors. And both kinds of photorecptors snag light with molecules known as opsins" [p. 126]. This is as would be expected if eyes of insects and humans evolved from some very early common ancestor which evolved a simple way to detect light. Later elements like the lens of a more advanced eye evolved out of a transparent protein called crystallins, which existed well before the eye used them to build a lense.

This puts the lie to another accusation made against evolution, that only microevolution has been demonstrated (slight changes within a given species, such as foxes with different colored fur in the arctic and the temperate zones), not macroevolution (the evolution of new species). Small changes, over a long enough time, can lead to major differences in the way a set of genes shapes the organism. It is not a quirk of some intelligent designer that all mammals have virtually the exact same skeleton, even though the bones are often put to very different uses: whale "hands" are fin for swimming, bat "hands" form wings, and human hands can create complex tools. The same goes for feathers, which evolved from scales, serving various uses during the intermediate period between scales and flight feathers.

Despite all this evidence, the same false accusations are made over and over and over again by proponants of creationism and intelligent design. Yet they claim it is the scientists who are dishonest, giving the public a false sense of certainty regarding evolution. [For one example, see: http://www.discovery.org/scripts/viewDB/filesDB-download.php?id=118 .]

Evolution of the Human Brain

http://www.physorg.com/news81709891.html

The above link is to an article describing a discovery relating to how the human brain differs from the brains of other mammals and may shed light on how our brains have evolved to allow more complex thought. To quote the article: "Cell adhesion controls many aspects of brain development including growth and structure, and enables neurons to connect with other neurons and supportive proteins. Differences in the molecular connections of human neurons compared to the neurons of chimps, mice and other animals, could help explain why the human brain is capable of far more complex cognitive functions."

This discovery is related to DNA sequences that determine when genes are switched on or off. The effect of DNA is not just to determine the genes and hence the morphology of the organism. The same genes can generate different features in an organism depending on when it is allowed to work and when it is prevented from working. This could explain why humans and chimpanzees share 98 percent of the same genome, yet the end result is quite different. This provides a new avenue for evolution, one that does not change the genes but when they turn on and off. For more on this idea, see the next article.

Talking Bones

The September 2006 issue of Discover magazine had an article about a scientist who practices a science called paleopathology. This is the application of the science of pathology, which attempts to understand health problems of living things, to paleontology, which is the study of fossils. Since fossils are mostly of the bones of creatures who lived so long ago their solid remains have turned into stone, studying the bones in light of our current medical understanding can reveal many things about the creatures of the past.

In the article, the scientist, Bruce Rothschild, discusses his findings about a variety of ancient and not so ancient creatures. He has challenged the idea that certain dinosaurs walked upright, because their bones do not demonstrate the types of fractures and other deformation that normally come from such a posture. He has also bolstered the theory that dinosaurs like the Tyrannosaurus rex did walk upright. Other findings suggest that T-rexes may have ad rough sex.

Another finding relates to creatures that dive deep underwater to catch prey. Diving too deep for too long and rising too quickly can lead to a condition called the bends, in which bubbles of gas form in the bloodstream which can cause damage to the brain and joints. But Rothschild has found evidence of the bends in the bones of certain diving creatures of the past. This suggests that some creatures evolved a way to cope with this condition and survive where others would be killed or crippled. He hopes this may lead to ways of allowing humans who dive deep to cope with the same problem.

Critics of biological evolution try to cast doubt upon the value of fossils in proving evolution. In fact, fossils are a very rich window on the past, allowing us to understand many intricate details of life forms that are no longer around. The changes in bone structure over time gives enough evidence of evolution to establish the theory, even if there were no other evidence for the theory (which there is). This shows the lie that we cannot test the theory of evolution because we cannot test theories with experiments.

Just as the forensic scientists who investigate crimes can testify to events of the past based on evidence found in the present, so can paleontologists describe the creatures of the past based on the evidence they have left for us to find millions and even billions of years later.

Evolution of Planets

I have not posted in a while, not because there is no news relevant to evolution, but because I have been in the middle of a career switch and rather busy.

Recent news reports have announced new and significant evidence for the hypothesis that planets form from dust that is scattered in space and gradually coalesces due to the mutual pull of gravity. The idea has been around a long time and I know of no reputable scientists who questions the idea. It is in perfect accord with both theory and observation. But science likes to confirm with more than plausibility. It likes to see evidence that definitively establishes a theory beyond any doubt.

For some time now, powerful new telescopes such as the Hubble Space Telescope have been detecting planets around stars. Telescopes have also detected stars with a disk of dust around them, something like our planet Saturn with its rings. The latest observations are of a planet and a disk around the same star and the planet is aligned with the disk.

What does this have to do with evolution? Evolution requires time. There is a wide range of evidence to suggest that our planet has been supporting life for several billion years, with the planet forming about 4.5 billion years ago, perhaps a billion years after the formation of the sun. This idea is also consistent with observations of other star systems, but now we have an observation that fills a small gap in this evidence.

It is also evidence that evolution, in a general sense, is a universal aspect of our universe. Science asserts that all stars form from clouds of dust and simple atoms and molecules that can be observed throughout our galaxy and others. When a critical amount of this matter forms, the forces of gravity overcome the forces holding the atoms apart and we begin to get nuclei fusing together and giving off energy, which accounts for starlight. It also keeps the star from collapsing further, as the energy given off pushes atoms apart on average as much as gravity pulls them together.

The earliest stars were probably made of just two elements, hydrogen and helium, the simplest of atoms. But when stars are really big, they burn through their nuclear potential and collapse some more and this leads to an explosions called a nova or a supernova. This fuses heavier atoms to form the heaviest of atoms so far observed. All this matter drifts out from the star, but globs of it can be drawn together again by gravity and a new system can form. Some of this heavy matter can form planets.

Some planets, such as earth, have the right amount of water and other chemicals to foster life. That life necessarily starts out simply, as complex self-replicating molecules. Over time, the process of natural selection begins to nurture evolution of these forms, and the process can lead to creatures such as ourselves.

So simple atoms evolve into heavier atoms which evolve into chemicals which evolve into life which evolve into self-conscious life, which evolve things like the Internet and blogs. Creationists and intelligent design exponents do not say much about the evolution of stars and planets. First it contradicts the idea that the universe is much older than indicated in Genesis. It also makes the idea of biological evolution all the more plausible.

Evolution happens. It is a wondrous thing. It is only a problem to those whose religion clings to the idea that human beings are extra-super-duper-special, the center of universe. But we don't have to be the center of the universe to be special or wondrous.

Secrets of Bat Machismo From Discover magazine, May 2006, p. 17: A species of bat has been discovered with very large testicles and very small brains. This is explained as follows: "Testicles are almost always bigger in animals species in which females mate with multiple partners.... When females are promiscuous, the sperm of different males must compete to fertilize each egg. Because males with more sperm have a better chance of producing offspring, the frequency of large testicles in those species increases. The pattern holds among all animals, including primates. Gorillas, who keep their harem close, have small testicles, while libertine chimpanzees have large ones. Those of humans, whose mating habits fall in between, are midsize."

The connection to brain size is that both a large brain and large testicles take a lot of metabolic resources. So we would expect that bats that need big testicles to gain an advantage in reproducing would have smaller brains to compensate.

Evidence was collected for 334 bat species. "In species with unfaithful females, males invest almost five times as much in testicles and 27 percent less in brains."

Origin of the Ear From Discover magazine, May 2006, p. 16: "Our earliest ancestors may have breathed through their ears." "The tubes that form the middle-ear canal in humans probably evolved from a pairof gill-like holes that allowed primeval sea creatures to breathe from the back of their heads."

The evidence: fossils dated at 370 million years ago of an intermediate species between fish and the first four-limbed animals to crawl onto land. This species "had small bones in its skull that appear to be early analogues of both ear canals and the gill system in some modern fish." When the creatures evolved to walk on land and breath air through the mouth, the canals were no longer needed for breathing, could develop into ears.

From Discover Magazine, May 2006, p. 13: Are We All Asians?

While most biologists agree that humans have evolved from earlier species of primates, this article points out that the location of these early ancestors of humans is not established. Some believe the evolution occurred in Africa and that humans spread elsewhere relatively late (80,000 years ago). Two scientists, Robin Dennell and Wil Roebroeks, suggest that we don't have enough evidence from Asia to discount it as a starting point for human evolution.

Another scientist, Spencer Wells, supports the Africa hypothesis, but added, "That Homo erectus could have origins in Asia would be potentially shocking, but I think that what Roebroeks and Dennell are saying reflects the state of the field. We certainly don't have enough fossils. Perhaps we are never going to be able to test the hypothesis."

This shows how open scientists are to having their favored interpretation of the evidence overturned by new evidence. It is how science advances.

Note that if new evidence turns up for humans evolving in Asia, it would not discredit the idea of evolution, only a prominant hypothesis about a particular detail of it.

Introduction: Evolution Defined

One popular misconception perpetrated by intelligent design proponants and creationists is that evolution is "just a theory," implying a significant degree of uncertainty. There are two aspects to correcting this misconception.

First, evolution is not in any sense a theory, speaking strictly of the concept of evolution. Evolution refers to a type of change that has nothing theoretical about it, any more than the concept of velocity is a theory. Velocity refers to an observable phenomena associated with motion. Evolution refers to a method by which certain changes can come about in a certain type of population. One can point to many examples of it, and one can create any number of examples in computer simulations. Evolution happens.

Evolution happens under the following circumstances:

1) One has a population of entities which are nearly, but not completely, identical.
2) These entities reproduce or are reproduced such that the copies are nearly, but not completely, identical to the original. Earlier members of the reproducing population are eventually replaced by these copies.
3) There is something about the situation which causes certain individuals of the population to produce more copies of themselves than other members. This happens consistently over a number of generations.
4) The differences in reproductive rates eventually brings about a change to the general characteristics of the population compared to an earlier generation.

Examples: One could write a program which starts with a set of 1000 numbers, each number between 1 and 100. The program picks a number from the set at random and evaluates whether or not the number is prime or not. If the number is prime, the program copies the number twice into a new number storage area. If the number is not prime, it is reproduced just once in the new area. Once the new area has 1000 numbers, the program starts again with the new set of numbers. Each iteration of the program will generate a new set of 1000 numbers. If this is kept up long enough, one would find almost all the numbers in the latest set to be prime numbers, even if the original set had only a nominal number of primes.

Other examples include selective breeding of dog or horses to produce animals with a certain trait, competition in the marketplace which over time changes the features on a product such as telephones. Even ideas evolve. Ideas exist in people's heads or minds, and are reproduced as new people are born and are exposed to the ideas. Ideas like racism were once very common, but today, the idea is found less and less.

This is not controversial. But when most people hear the word evolution, they think of the evolution of the species. This refers to the theory that the differences in animal and plant species that we observe in the world today are the result of a process of evolution. In this case, the population of entities is a biological creature such as a redwood tree or a robin or a dolphin. These populations reproduce by way of copulation and giving birth to new members, who grow up to replace the parents. Most dolphins are very similar to each other, but not identical. The selection occurs when the environment changes so that creatures with some feature have a better than average chance of surviving and reproducing than other members. For example, members of the species with a particular coloration might prove harder to see in the new environment, meaning they get captured by predators less frequently and so reproduce more frequently. The gene that produces the coloration is more common in the next generation, so more of the offspring have the coloration. The process can lead to the entire population changing from one color to another.

The mechanism of evolution is perfectly logical. The only thing theoretical was (back when the theory was first proposed) whether or not the differences in creatures actually observed could be explained by environmental selection. Over time, more and more evidence has been found to support the theory of evolution of species until now, evolution is considered the actual explanation for diversity of species. The only things in questions are particulars of how quickly changes can occur and the mechanical details.

This blog will be listing examples, hoping to demonstrate the reasonableness and value of this idea.

POSTING GUIDELINES: Please limit comments to the relevance of the particular example as evidence for natural selection as the explanation for the diversity of species. This is not the place to debate religious doctrine. (I'll have another blog where that will be appropriate.) Comments which are abusive will be deleted. Off-topic comments will be deleted.