A critical test of common descent (evolution)

While there are ways to experimentally test the process of evolution, known as natural selection, by mimicking it artificially, ways to test the historical issue of evolution, known as common descent, must rely on making observations and making predictions of the outcome of those observations.Inside the cells of all Eukaryota (plants, animals, fungi, and protists) are organelles called mitochondria. Likewise, inside the cells of plants are organelles called chloroplasts. Both mitochondria and chloroplasts have their own DNA and are thought to be descended from bacteria that took up residence inside the larger cells. In any case, the DNA in those organelles are completely different from the DNA in the nuclei of those same cells.

We can take the DNA of cell nuclei and check them to see if the differences between those of various organisms can enable us for build a family tree of those organisms. The more similar their nuclear DNA is, the more closely related they are. But since mitochondria and chloroplasts also have DNA, we could also take them and check to see if we could build up a family tree that is the same as the one we would build up with the nuclear DNA.

Indeed, there is no reason, if all life was produced by a single recent act of creation, for the DNA of the mitochondria of all animals to be significantly different from each other. So if I was a Creationist, especially of the young Earth kind, I would predict that it would be impossible to make a family tree from mitochondria DNA, or if I did, it would be completely different from the nuclear DNA. But if I was testing the theory of common decent, I would predict that the readings in animals of both their nuclear and mitochondrial DNA would produce the SAME FAMILY TREE in all cases! This would make perfect sense if the mitochondria and the rest of the cells have been evolving together ever since they first came together over a billion years ago.

Mitochondrial DNA is already used in forensics to determine who the mother of a child is, while nuclear DNA must be used to determine the father of that same child. This would only be an extension of that function, since the parents of the child must be of the same species, or at least very closely related, to even produce offspring at all.

A Real Skeptic vs. a Denialist

A skeptic is defined as someone who reserves judgement on an issue until enough evidence is found to support a claim beyond a reasonable doubt and also clearly defines what would make him disbelieve a claim. This is scientific thinking.

By contrast, a denialist has no such defined limits, either of belief or disbelief. The denialist starts from a position of dogma, asserting opposition to an idea by presenting a contrary idea as absolute truth and interpreting all evidence according to that unalterable dogma, rather than draw conclusions based only on the evidence. This is the opposite of scientific thinking, although denialists often use scientific terminology to make their positions seem legitimate to fool the ignorant.

Denialism vs geuine skepticism is found in debates over evolution vs. Creationism, global warming, religion, and politics. If there were no denialists, most of those debates would have either ended long ago, or would be a lot more cordial than they tend to be.

Why the term “species” should be abolished

The term “species” has a clear definition in biology: a group of organisms that breed only among themselves and do not breed with members of any other group. Thus, as far as we can tell, humans are all members of the same species, Homo sapiens. 

The lesser black backed gull and the herring gull of Britain, however, act like separate species, yet are connected to each other by a ring of subspecies that extend all around the Northern Hemisphere and can interbreed with their neighbors. So in the sense I stated above, the definition of species breaks down.

The issue of species also fails when asexual life forms are considered, including bacteria, most protists, a few populations of beetles, a population of lizards, and an entire class of rotifers called Bdelloidea. The lizards, beetles and rotifers in question are all females, while among the single celled organisms the issue of gender identity is meaningless.

Suppose we have a population of 400 asexually reproducing lizards which are genetically and physically almost identical. One at a glance would assume they are members of the same species. But because the lizards do not swap genes via sexual reproduction, they would just as well be considered 400 separate species.

The issue of “species” becomes meaningless when one considers extinct organisms that are dug up as fossils. Fossils cannot breed among themselves and so the designation of certain fossils as Homo hablis, Homo egaster, and Homo sapiens is entirely arbitrary, based on the structure of the fossils and nothing more. The same is true of all other organisms in the fossil record, including dinosaurs.

I would therefore argue that the term “species” is really useless and should be abolished completely, because it is a source of unnecessary confusion.

A useless debate

The crazy thing about debating with Creationist hypocrites is that they have ZERO facts that actually support their case, but plenty of rhetorical tricks. I was reminded of that by a “Sirius Knott” who plastered some lame comments on one of my blogs. Here’s the confrontation between him (SK) and me (DH), for those who care to follow it:

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Amphibians as a Support for Evolution

I am always amused by Creationists’ denials that transitional forms exist among either fossil organisms or living species. After all, the definition of “transitional” depends on the existence and forms of two other organisms that the transitional form is being compared to. Thus Archeopteryx is called transitional because it has characteristics of both birds and theropod dinosaurs, which are reptiles. But if neither birds nor reptiles existed, then Archaeopteryx would not be transitional to anything.

It is the same with amphibians. Their very existence as a class is evidence of evolution, for they are clearly transitional between fishes (which are almost entirely confined to water, breath through gills, have fins instead of legs, and lay jelly-like eggs), and reptiles (which often have legs, can thrive even in dry deserts because they breath through lungs, and lay hard or leathery shelled eggs on land). Most amphibians as adults can live on land by walking on legs and breath air through lungs, but they lay eggs like those of fish and have a larval stage that lives in water and breaths through gills. So one could argue that a salamander is a modified fish or that a lizard is a modified salamander, thus regarding the salamander as a transitional form having characteristics of both.

One might also think a Creator of all living things from scratch would not bother to make animals with such lifestyles as amphibians. What would be the point, except to trick us into accepting evolution?

The forms of living amphibians also give us some insights into how evolution works:

  1. The Urodeles include the news and salamanders which have short and weak limbs, long bodies and tails, and a larval form that resembles the adult.
  2. Anuarans (frogs and toads) have very short bodies, powerful limbs, and no tails as adults, but have a very different larval form with a strong tail for swimming and no limbs. They are the most common amphibians.
  3. Gymnophiores, also known as caecilians, have no limbs at all and have extremely long bodies but little or no tail and live almost entirely underground. Indeed, they resemble giant earthworms.

It is easy to see how both frogs and caecilians could have evolved from salamanders by going in completely different directions. One might also suspect that salamanders are a transitional form between frogs and caecilians, but in fact the salamanders are the primitive forms most closely resembling the fish and lizards mentioned earlier, while the other amphibian forms resemble neither fish nor lizards, but are more specialized in their lifestyles.

Most fossil amphibians from the Devonian period to the Permian period have the form of salamanders, thus providing support for the hypothesis that salamanders are indeed the primitive form. In the mass extinction at the end of the Permian period, the giant amphibians that had been so common on the land disappeared. Later, one line of smaller amphibians developed into frogs in the Triassic period. Today, with so much competition from reptiles, birds and mammals, the smaller amphibians, numbering only 4,000 species, are a remnant of what the class once was.

Why science education must be naturalistic

One of Creationists’ most serious objections to how science is taught to students in most public schools is that all supernatural explanations (miracles) are rejected out of hand, and this somehow limits the vision of scientists. But the truth is actually the opposite. To explain why, consider this scenario:

Supernatural explanation:

Child: Daddy, what causes lighting and thunder?

Father: God sends lightning bolts and thunder blasts to frighten people into submitting to His will.

Scientific explanation:

Child: Daddy, what causes lighting and thunder?

Father: Lightning is caused by unequal electric charges between two clouds or between a cloud and the ground causing a massive discharge of electricity. Thunder results from lightning heating the air and causing it to expand suddenly, producing powerful sound waves.

OK, Creationists, would you want BOTH these explanations taught in science classrooms regarding how weather occurs? Well that’s about as silly as requiring any form of Creationism taught alongside evolution! There is no evidence whatsoever that God directly causes lighting or thunder, and indeed such an idea might lead to the assumption that anyone struck by lighting was being punished by God. This is “magical thinking” which, if it had not been questioned centuries ago, would have prevented research into finding ways for people to avoid lighting by understanding how it behaves. Thus, any supernatural explanation, one that totally ignores or negates the known laws of physics and chemistry, would be no explanation at all, but merely an argument without evidence. And that is exactly why Creationism can never be scientific, but evolution is. Evolution is consistent with all known scientific laws, it is based on physical evidence, and it leads to more research. Acceptance of Creationism, or even the assumptions that allow for Creationism to be considered credible, would bring scientific advancement on almost any subject to a grinding halt, because you could then simply dismiss any unusual or complex phenomenon by saying “God did it, I believe that, so it’s settled”.

Therefore, there is no place for the supernatural in science education.

The Blunder from Down Under

An Australian member of Care2 known as Freediver has been a pain in my @$$ for nearly 2 1/2 years. He is mentioned in this earlier blog of mine:


Among other disgraces, he opposes the teaching of evolution as science in high schools, favors the harvesting of wild animals as an alternative to eating meat from factory farmed livestock, and even champions whaling, which is totally unnecessary since all the things that whales provide can come from other sources, whether natural or artificial. His arrogant manner of expression is highly offensive to many other Care2 members, who see him as a useless buffoon. But he somehow is possessed by delusions of grandure typical of sociopaths.


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A fake evolution site!

I’ve always known that the dogmas of Intelligent Design are unscientific and thus do not belong in any science class, but when I discovered how far some of its promoters were willing to go to trick people into reading their crap, I nearly blew a gasket in my brain!

First, look at this:


The home page has the title, “EVOLUTION NEWS & VIEWS” but this site is about anything but that. In fact, it contains news of, and arguments to promote, Intelligent Design.

To illustrate the incredible stupidity and dishonesty of the people running this website, I will cut and paste two articles from it. Continue reading

Dale Husband’s Evolution Experiment

One of the objections to the idea that various organisms living today have a common ancestry is that, while one may infer such a thing from fossil, structural, and molecular evidence, one can never actually see such processes of evolution happen because they would take millions of years, and thus human beings could never live long enough to see macroevolution directly. That would indeed be true if we could rely only on natural processes of random mutation and natural selection. But what if it was possible to accelerate the process of evolution, to use artificial selection and genetic engineering to test whether there are limits to how far evolution can go to a line of organisms?

First, we must consider that humans have already done artificial selection to plants and animals for thousands of years, resulting in higher food yields from those domesticated plants and animals we eat as well as various forms that have other purposes to us, including for companionship and for their beauty. Darwin used such cases of artificial selection as examples of evolution, and suggested that natural selection operated in a similar way. It stands to reason that we could use genetic engineering to both make greater changes to domesticated plants and animals and mimic natural selection as it may have happened over millions of years in the past.

Creationists have claimed that lines of organisms can evolve, but only to a certain degree; they could never go beyond the limits of a “created kind”. At present this is entirely an assumption based on dogmas drawn from the Bible. What we need is an experiment that could actually support or falsify that claim, and at the same time demonstrate evolution in action. And I have come up with just such an experiment.

It is common knowledge that crocodilians are distant relatives of birds, both being members of the Archosaur clade. Dinosaurs are also thought to belong to this same clade. My proposed experiment involves performing genetic engineering on crocodilians to see if one can turn them over several generations into dinosaur-like animals. One must note that while crocodilians are a sister group to dinosaurs and most are generalized in nature, birds are actual descendants of dinosaurs and most of them are highly specialized for flying. One might choose a rather unspecialized and flightless bird, such as an ostrich, for the subject of the experiment, or a typical crocodilian. The ostrich might be less suitable because to make a dinosaur-like creature from it would be both a backward step and would not be a spectacular enough change to demonstrate that there may be no limits to how lines of organisms may change in nature. Therefore, a crocodilian would be better. And in my judgment, the best possible subject would be the American alligator (Alligator mississippians) because it is unspecialized, readily available, and abundant, unlike some other crocodilian species, which are endangered.

Having selected our subject, we may proceed with the next step, which is to determined the entire sequence of the genetic code of the American alligator. After this is done, we then take a population of alligators and make a few changes to the alligator genes, the sort that could happen due to natural mutations. These changes may cause the offspring of the first generation of alligators to still look like members of the crocodile order, but with unusual traits that no current alligator or crocodile today has. Then we make a few further changes to the genes of the members of the second generation of alligators. We repeat this process for every succeeding generation until about a dozen or so generations of alligators have been produced, resulting in creatures that no longer even resemble alligators, but look like dinosaurs.

Anti-evolutionists may argue that while such an experiment may seem to show evolution in action, it would not prove that such changes can occur naturally, and would instead point to intelligent design. This argument, if its premise is accepted, would actually invalidate any experiment, since one could always claim that any experiment may not mimic exactly circumstances and processes that occurred millions of years ago. Also, the intelligent design claim would only be valid if we made the alligator to dinosaur leap in one generation, instead of taking a dozen or more generations as I am proposing.

If it turns out that in fact there is a mechanism which prevents genetic changes to a line of organisms beyond the limits of a “created kind”, then there may come a point in the experiment where attempts to make further changes to the alligator population fail and either the next generation members end up badly deformed or they do not change at all. After several attempts to make the changes have failed, the next logical step would be to find the mechanism and identify exactly how it works. We may then locate this same mechanism in many other species of animals and plants. And the discovery of this mechanism would put evolution as a valid theory to rest forever.

On the other hand, the success of the efforts to make dinosaur-like creatures from alligators would give vital support (but not absolute proof, for in science there is no such thing) to the idea that dinosaurs (and birds) could have evolved from very different animals naturally and would make Creationist claims look even more ridiculous than they already do.

Evolution 101

Evolution is the scientific theory that is intended to explain the diversity of life on Earth. The most basic definition of it is “cumulative change through time”. In biology, it says that populations of organisms are subject to change as a result of environmental factors acting on them and causing them to adapt to specific environmental changes.

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The “chain of reason” in the global warming issue

There are four links in that chain, and all must be solid for the man-made global warming issue to be valid. Nothing else matters.

  1. Has CO2 levels in the Earth’s atmosphere been increasing over the past century? Scientific reports indicate that is the case.
  2. Is CO2 a gas that causes heat to be retained in an atmosphere, thus making it a “greenhouse gas”? Scientific reports indicate that is the case.
  3. Does human industrial and transportative processes produce vast quantities of CO2 in the Earth’s atmosphere? Scientific reports indicate that is the case.
  4. Has the average global temperature actually increased over the past few decades? Scientific reports indicate that is the case.

Those who throw around issues like nuclear power, questionable reports of exceptional weather, recent solar output, or natural climate changes in ancient or prehistoric times, only seek to cloud the issue. Unless and until you deal directly with the four central issues at the heart of the global warming issue, you have no real case.

The chain of reason remains unbroken.

Was our Solar System Intelligently Designed?

The concepts of “young-Earth” Creationism and Intelligent Design, which may seem halfway plausible in the field of biology, completely fall apart when attempts are made to apply them to the field of planetary astronomy. The very structure of the Solar System casts doubt upon the notion that an Intelligent Designer created it only a few thousand years ago.

  1. The orbits of the planets do not exist as circles, but as ellipses. In ancient times until the 17th Century, most astronomers insisted that the planets moved in circles because circles were held to be “perfect”.
  2. The surfaces of most solid bodies in the Solar System are battered with craters, indicating a violent and chaotic process of formation.
  3. As the recent controversy over the (dwarf) planet of Pluto showed, it is almost impossible to consistently categorize the various bodies of the Solar System.  Several moons of the gas giant planets, for example, are bigger than Mercury.
  4. The space between the orbits of Mars and Jupiter are filled with thousands of rocky masses known as asteroids. They serve no practical purpose and even pose a serious threat to life on Earth. The extinction of the dinosaurs, for example, is thought to have occured due to the impact of an asteriod 65 million years ago. Many asteriods even have orbits that take them dangerously close to Earth.
  5. The Earth’s rotation period (the basis of our “day”), the moon’s revolution period (the basis of our “month”), and the Earth’s revolution period (the basis of our “year”) do not match up precisely, making the formulation of calendars a very complicated business.
  6. There is no consistency to the rotational period of the planets. Earth and Mars have 24 hour days, but a day on Jupiter is less than 10 hours long, while a “day” on Venus is 243 times longer than that of Earth. In addition, Venus rotates BACKWARDS!
  7. Venus itself is a planet so hostile to life that astronomers, including the late Carl Sagan, have compared it to the Judeo-Christian vision of Hell.
  8. Far beyond the orbit of Neptune, there exist millions of tiny comets, some of which are drawn close to the Sun, resulting in a spectacular display as its ices sublime, producing the comet’s “tail”. But these comets could also collide with Earth, posing another threat to life on that planet.
  9. All four gas giant planets have rings, but there is no consistent pattern to them. 
  10. Most of the planets have an axal tilt, but Uranus and Pluto are turned more than 90 degrees from the vertical.

If I were an Intelligent Designer, would I have made the Solar System only a few thousand years ago in such a chaotic way as to fool scientists into thinking that it had formed billions of years ago of entirely naturalistic forces?

Certainly not!

We need a scientific, not religious, approach to ethics!

For thousands of years, people have created for themselves societies to live in and have expressed moral codes to both define those societies and to recommend improvements to them. Because all human beings are imperfect, the moral codes they create are also imperfect, but the principles of free inquiry, experimentation, and empiricism enable us to determine those ethical codes that work better than others in creating and maintaining societies that work for the good of the most people.

The danger comes when misguided people attempt to impede one or more of these processes. They suppress free inquiry though censorship, they cut off social experimentation through political tyranny favoring the status quo, and/or they deny empiricism by invoking religious dogmatism to claim without proof that a certain moral code from ancient times is as applicable today as it was when the moral code was first formulated. The results have been clearly shown repeatedly throughout history: social stagnation leading to violent revolution, leading again to social stagnation. Various forms of bigotry and extremism expressed by people either favoring one group of people over all others, or attempting to be “consistent” with a narrow point of view that itself cannot be supported empirically, result in social divisions that lead to violence when those impulses are not restrained.
Science by itself cannot dictate ethics, but it can and should test ethical standards and rules that originate from religion and philosophy to either support or falsify them. The best rules are those that provide for the welfare of the most people over the longest period of time, rather than those that help a group of people in the short term.