Creationist Meme Week, Part 5: Hope You Kept The Receipt For Your Education

Frogs to Princes

I don’t know what university you attended, Mr Carlson, but at my university I was taught that princes (and by extension all humans) did not evolve directly from modern frogs. All modern life descends from a common ancestor. Rather than being our greatest grandparents, modern frogs are our distant, distant, distant [approximately 50 instances of the word distant deleted] distant cousins.

Mr Carlson, like so many Creationists, seems to be confused about how the tree of life is organized. He apparently views it as an obelisk, with single-celled organisms at the base and humans at the pinnacle. Falling somewhere in between are frogs, monkeys, paramecia, and every other organism which Creationists have mockingly (and mistakenly) placed in humanity’s evolutionary history. No wonder Mr Carlson mocks his understanding of evolution! I mock it also!

The tree of life, if you were to visualize it properly, would look more like…you know…a tree. A really freaking big tree. This metaphorical tree started growing when life began on Earth, and it put out its first branches as life diversified and expanded to fill all the niches available to it. The branches spread out along crooked paths, splitting over and over, pushing into new territory. Many times a branch just stops; here some species met a challenge to which it could not adapt, and perished. The tree is full of these dead-end branches but every time a branch comes to an abrupt halt, other branches diversify to fill the space going forward. No region stays unoccupied for long.

At the top of the tree are all species that are still alive, including humans, chimpanzees, and yes, frogs. If you want to see how a human and a frog are related, you have to follow their individual branches back in time to the point where they meet, but what you find there will be neither frog nor human. You won’t recognize it, because you’ve never seen anything like it, but it’s your great great great [approximately 68 million instances of the word great deleted] great grandpappy, and mine, and that of all frogs. So tell it I said hi. Or ribbit. Or whatever.

It is a mistake to think of humans as occupying a special place at the endpoint of evolution, which is why biologists don’t think that way. In fact, nobody but a Creationist thinks of evolution as a linear morphing of X into Y, where X and Y are both extant species. If you want to discredit the idea of evolution, you have to understand how it is supposed to work. If you refuse to educate yourself even to that extent, then you have little business calling one of the most well-supported ideas in scientific history into question.

I would recommend that Mr Carlson read The Ancestor’s Tale by Richard Dawkins if he wishes to truly understand the relationship between frogs and princes. I would recommend that, but many Creationists begin frothing at the mouth at the mere mention of Dawkins’ name. See, they regard him as something of bully. Granted, that’s not an entirely unwarranted opinion, but at least the man understands evolution.


Creationist Meme Week, Part 4: Raptorous Ignorance

Raptor Questions Evolution

Before anybody can answer this question from an evolutionary perspective, somebody (this dinosaur, perhaps) needs to define the terms information and advanced unambiguously. Creationists won’t do that, though. They don’t actually want scientists to answer this question, they just want to be able to claim that the question is unanswerable.

What if somebody gives you the odd task of copying a cookbook for a restaurant? It’s important to be precise, because the restaurant depends on the recipes to stay in business. If you make a mistake, the restaurant’s business could be hurt. It might even have to shut down. No pressure, right?

As you laboriously copy page after page, you might start to think about the mistakes you could make. What if you left out a key ingredient for the lasagna recipe, say, oregano? This tiny deletion causes a loss of information, and that loss could be harmful to the restaurant. Perhaps its patrons will not like this new, oregano-free lasagna. (For the purposes of this story, we’ll assume the chefs are mindless automata who will not add oregano unless the recipe specifically calls for it. Not very realistic, I guess, but I’m going somewhere with this.) That’s not the end of the world, right? It’s not like you skipped the lasagna recipe altogether.

But what if you did? That could be even worse for the restaurant. That’s a lot of information gone missing. What if lasagna was the restaurant’s signature dish? The place’s reputation could be ruined. Ruined!

Are there any errors you could make that don’t involve a loss of information? Certainly. You could make an accidental substitution. The severity depends on what substitution you make, and where. Suppose you type basil when you meant to type oregano (and doesn’t that happen to everybody?). What effect would that have? Honestly…not much. It would be a silent change to the menu. The end result would be the same, without a net loss or gain of information.

Not all substitutions are harmless. You could try to type tablespoon of oregano but accidentally type pound of live cockroaches instead. Yeah…enjoy not being in the restaurant business anymore.

Are all potential mistakes bad or neutral? Are there no happy accidents? Well, maybe there are.

What if you made an accidental substitution that enhanced the flavor of the dish whose recipe you were copying? Suppose you substituted essence of pure flavor for oregano? What if people loved the change? What if your restaurant’s business boomed because of it?

What if you accidentally copied a page twice? No big deal; you just have two pages that code for the same dish. But what if you made a happy mistake on the duplicated page? Now the restaurant not only has the original dish that everybody likes; it has a new dish that everybody will love! Information has been added to the cookbook, and the restaurant is better off for it. The restaurant’s superior recipes will allow it to outdo its competitors. Your famously flawed recipe book will spread like wildfire. Nice, huh?

If you remember biology, you probably figured out where I was going with this analogy a long time ago, and you’ve been patiently tapping your pencil on your desktop waiting for me to wrap up. Thank you for your patience. If you don’t remember anything from high school, I’ll quickly bring you up to speed.

Although cells are very careful to copy their genomes precisely, mistakes happen. These mistakes are occasionally passed on to the next generation. Many of the mistakes are neutral or silent, which means they have absolutely no impact on the health of the organisms that host them. Some of the mutations are harmful, which is bad news for the bearer but it means they don’t travel much farther in a population’s gene pool. Some mutations are good; these are the ones that get propagated in the population. Occasionally the cards all fall into line: a chunk of genetic material gets duplicated more than it should, and the extra chunk acquires a beneficial mutation. Now the organism not only has the original trait, but a novel, useful trait as well.

Suppose you have a chromosome whose sequence of genes (represented by letters of the alphabet) looks like this:


During the process of gene replication, each gene is copied and wound into a new chromosome. When the cell divides, each daughter cell receives a complete copy of the chromosome. But imagine that at some point the gene sequence FGHI is over-duplicated and reinserted into the chromosome, resulting in this:


Now imagine that the new copy of gene G undergoes a point mutation – in this case, a beneficial mutation. We’ll denote the mutated G as G*. Now the chromosome looks like this:


So the host organism not only gets the benefit of having a functional copy of gene G, it also gets the benefit of gene G*. Its genome has become more advanced. It will be more successful at the three F’s – feeding, fighting, and mating – and it will leave behind more offspring than its fellow organisms that do not have the beneficial G* mutation. That’s natural selection, which leads to evolution.

I fully expect you to ask “What are the odds of this happening?” It does seem like a long shot that a gene duplication would be followed by a beneficial mutation. I won’t lie: it is a long shot. The kinds of mutations that benefit an organism might be one-in-a-million, or one-in-a-billion. But here’s the thing: that happy mistake only has to happen once – just once among the millions or billions of organisms struggling for survival within a population. Once an adaptive trait appears, nature will select it for propagation. When you consider the fact that the living creatures on Earth represent a constantly-running biological experiment to find new and improved genetic codes, the question isn’t “How could mutations produce more advanced life?” The question is “How could they not?”

Creationist Meme Week, Part 3: Fossilize This

Fossils and Creationism

Imagine a football game between two drastically mismatched teams. As the final seconds of the fourth quarter tick by, it’s obvious that the game is going to be a major shutout: 73-0. After the struggle is finished, the teams’ captains meet to shake hands. The team that triumphed is captained by a man named Chuck, and the non-victorious team leader is called Kent. The conversation goes like this:

CHUCK: Good game, Kent. No hard feelings about the runaway victory, right?

KENT: Of course not! We won, after all!

CHUCK: Say again? The score board shows that the final score was 73 to zip; our team.

KENT: You’re mistaken. All the touchdowns were scored by our team.

CHUCK: Look, Kent, I have the tape of the game right here. As we speak I’m preparing special slow-motion replays of all the key plays from various camera angles. You can see our players crossing the end zone time after time. We clearly won!

KENT: We both see the same tape, but we interpret it differently. Some of those men scoring touchdowns could have been our players.

CHUCK: But they’re wearing our jerseys! You can see the color patterns right there on the screen! Here, let me zoom in and use sophisticated image-enhancement software to sharpen the details! Yes, these are clearly all our players scoring touchdown after touchdown!

KENT: I just don’t see it. You’re trying to suppress my point of view, which means that I’m right.

CHUCK: I’m not trying to suppress your point of view, I’m just showing you the evidence! You can even see it on the scoreboard! Our team won!

KENT: Oh sure, but your people run the scoreboard. You can’t trust that. I want it taught in schools that there’s a controversy regarding who won this game.

CHUCK: (DIES from exasperation.)

KENT: (BELIEVES he has won, then goes to jail for tax fraud.)

Okay, I know it’s not fair to pick on Kent Hovind for being thrown in jail. His criminal activities have nothing to do with his bizarre belief system.

Fossils are the remains of long-dead organisms. Fossilization is a pretty rare process – in order for an organism to be represented in the fossil record, it must have hard body parts (such as bones or a shell), and it must die in exactly the right environment where it can be buried before its parts are consumed or scattered. The fossilization process is also incredibly slow. Fossils less than ten thousand years old are virtually unknown. We have remains of organisms that lived less than ten millennia ago, but they’re not mineralized yet so they don’t really count as fossils.

Very few organisms leave fossils, and even fewer will be discovered. Scientists estimate that the fossil record represents far less than one percent of the species that have ever existed.

Given the relative rarity of fossil remains, you might think that piecing together an accurate record of the past would be next to impossible. Here’s an analogy: What if somebody gave you a copy of War and Peace from which all but two pages had been ripped, then asked you to summarize the plot based on the two remaining pages? It is true that there is much we’ll never know about organisms living in the past, but that doesn’t mean paleontologists cannot glean some information from the fossil record.

For example, we know that dinosaurs existed and that they did not all live at the same time, nor did they live at the same time as humans. An Allosaurus fragilis and a Tyrannosaurus rex never had to compete with each other for food, because they were separated by more than eighty million years, and neither one of them ever chased a fur-bikini-clad Raquel Welch.

Not only do we know dinosaurs existed, but scientists can see their evolutionary precursors and successors in the fossil record. And these rungs on the evolutionary ladder all occur exactly where they’re supposed to occur. Scientists never find a fossilized rabbit in the same rock layer as a Velociraptor, nor would they expect to.

It’s not just that scientists think fossils are ancient. Numerous lines of evidence point to the same conclusion (radiometric dating1 (PDF) and relative dating, e.g.). Even the scant fossils nature has spared paint a picture of evolution in action: in the oldest rocks there are no vertebrates – just arthropods and mollusks. Then fish appear, then amphibians, then land vertebrates, then mammal-like reptiles, then true mammals, then primates, then apes, then homonids. The picture might not be complete, but it’s complete enough to make out what’s going on.

If you ask a Young-Earth Creationist to explain how fossils support the idea of special Creation, he might point you to a site like the Creation “Science” Network. According to the authors of this page, fossil evidence supports the Noachian flood. It does nothing of the sort. It would take a level of precision not normally seen in a devastating flood to deposit the remains of organisms so neatly, and so consistently, into layers based on increasing complexity.

According to a Creationist, gaps in the fossil record mean that no evolution took place. Actually, gaps in the fossil record mean that no fossilization took place. But it doesn’t matter to a Creationist. If you point out an obvious “transitional fossil”, like Tiktaalik, a lobe-finned fish which seems to perfectly fill in the evolutionary gap between ancient fish and four-legged animals, the seasoned Creationist will demand that you provide two new transitional fossils to fill in the gaps on either side of Tiktaalik. It’s the Creationist’s version of Zeno’s Paradox.

Even if scientists had never discovered fossils, there’s still plenty of evidence that life evolves over time. The fossil record just strengthens our understanding of evolution. To deny the evidence for evolution is one thing, but to actually claim that the evidence bolsters Creationism…well, that’s especially brazen. It still doesn’t make you right.

1. Beware of Creationists (and well-meaning but underinformed realists) who speak of using carbon dating to determine the age of dinosaur fossils and ancient rocks. Carbon-14 dating, or radiocarbon dating, is only used to find the ages of things that were alive within the past 50,000 years or so. Also, radiocarbon dating has some well-documented limitations of which scientists are highly aware.

Creationist Meme Week, Part 2: Relevance, Anyone?

Relevance Anyone

This meme is no doubt in response to a video featuring Bill Nye (the Science Guy!), in which he says that Creationism is not appropriate for young children. His argument is that teaching children to doubt scientific reality hinders their development as critical thinkers and productive citizens. Ultimately, that’s damaging to our nation. I’ll let you hear it from his own mouth.

Contrary to what Mr Nye says, the United States is not unique in its widespread denial of evolution, although it is certainly one of the most populous nations in which such beliefs are common.

The memer sarcastically implies that since prominant historical scientists like Isaac Newton, Francis Bacon, Louis Pasteur, etc, did not believe in evolution, a belief in evolution must not be necessary to become a successful scientist.

That’s actually true; you don’t have to accept evolution in order to become a successful scientist, unless you’re planning on working in one of the life sciences and the year is post-1859.

And even if you work in some natural science that isn’t related to evolution, you’ll still need to understand how to evaluate scientific evidence. When you apply your analytical skills to the mountains of evidence in support of evolution, what do you think you’ll see? Exactly what 95% of scientists in general and almost 100% of life scientists have concluded: that evolution is a real and ongoing process.

But what about these scientific heavyweights who didn’t believe in evolution and still managed to be brilliant? Well, Newton, Bacon, and Kepler all died long before Charles Darwin’s On the Origin of Species was published. Whatever their feelings regarding the role of God in shaping life, it did not seem to interfere with their greatest works. In fact, Francis Bacon favored an entirely naturalistic approach to science. In his mind, you should leave the Bible out of it if you want to get anywhere. The fact that this Creationist memer chose to include a thinker who would probably be opposed to Creationism is nothing short of hilarious. It’s like Fox News accidentally using a photo of a lesbian couple in their “traditional marriage” article. Beautiful, beautiful irony.

Von Braun and Faraday were both alive when Darwin’s book was published, so they probably heard about evolution, but since they were not life scientists, it doesn’t really matter what they thought about it. Relying on the opinions of big name scientists to support your beliefs (even if those scientists were not involved in a relevant field) is called an argument from authority fallacy. The reality of evolution is not decided by who does or doesn’t believe in it; it’s decided by the evidence. I’ll have more to say about evidence later this week.

So that leaves Louis Pasteur. He was alive when On the Origin of Species was published, and he worked in the life sciences. And…Pasteur accepted evolution. He might not have believed that natural selection was its cause, but he definitely believed that organisms changed, and he believed that Earth had been around for at least a few hundred million years.

Now like I said before: it doesn’t matter whether Pasteur accepted evolution or not; all that matters is the evidence. But this fact remains: of the six scientists that this Creationist memer selected to prove his point, five of them were in no position to evaluate the evidence in favor of evolution. The one scientist who was in such a position accepted evolution.

Creationist Meme Week, Part 1: What Is Evolution? (TL;DR Version)

Then What Is Evolution

I don’t know, Morpheus. What if I told you that cylinders, driveshafts, tires, doors, headlights, and bumpers have nothing to do with automobiles? You’d probably say I didn’t understand the topic at all, or that I was barking mad. And if I made a statement as breathtakingly inane as the one in this meme, you’d be quite right to think so.

This is a common Creationist tactic called “moving the goalposts”. First, Creationists said that evolution never happened. Biologists showed that evolution happens everywhere, all the time. When the evidence became irrefutable, Creationists said fine, organisms can adapt within a created kind, but one species cannot evolve into another one. A fish cannot become an amphibian, for example. Paleontologists showed that organisms have been evolving from one species to the next for billions of years, and continue to do so. Scientists defined terms like natural selection, genetic drift, and speciation to describe exactly how species change over time. This Creationist memer seems to imply that these phenomena exist, but they don’t contribute to the process called evolution. What? If you argue that the very components of evolution have nothing to do with evolution, then you’re simply re-defining evolution in such vague and unattainable terms that nothing would ever qualify as evolution. You’ve moved the goalposts clear into the parking lot.

You don’t get to redefine scientific terms in order to discredit them. If you want to prove that evolution – a scientific concept – isn’t real, then you have to stay within scientific boundaries to do so.

Since we’re going to be talking about evolution a lot over the course of the coming week, I thought it would be helpful to define each of the terms in this meme. I should warn you up front: there’s a lot to talk about. Go ahead and grab another cup of coffee. I’ll wait.

What is evolution?. In simplest terms, evolution is a change in allele frequency within a population over time. Alleles are different flavors of a gene; they give rise to the various traits that make us diverse and wonderful. The word frequency refers to how often these alleles are found within the genes of a population. For scientific purposes, a population is a group of organisms belonging to the same species and living in the same region.

Anything that happens to change how often these genetic traits are found within a population is evolution. On short time scales, evolution causes minor changes within populations, but eventually little changes add up to big changes.

Now wait just a minute, you might be asking. When do we get mutant powers and the ability to breathe underwater? Well, that leads us to the next question…

What isn’t evolution? It’s really important to understand this, because Creationists rely on a (sometimes deliberate) misunderstanding of evolution to form their arguments. Here’s a partial list of things that aren’t evolution:

  • A chimpanzee giving birth to a human.
  • A chimpanzee turning into a human.
  • A chimpanzee learning some human language skills.
  • A human sprouting wings.
  • Anything you see on X-Men.
  • A half-duck half-crocodile.

All of these events (with the exception of the third item) would qualify as miracles, not evolution. A miracle does not have to obey the laws of nature; evolution does.

What is natural selection? Natural selection is the process that drives evolution. There are a few simple principles to remember:

  1. Resources are limited in any environment, so there will always be competition among members of a population.
  2. Genetic variation (arising from mutations) causes inheritable differences.
  3. Some organisms will have advantages over other organisms because of their interited traits. They will be more effective competitors for food, shelter, mates, etc.
  4. Due to the increased health and vigor afforded them by their inheritance, these organisms will reproduce more often and leave behind more viable offspring. Their advantageous genes will proliferate in future generations, while the offspring of the less well-adapted members of society become marginalized.

And that, my friends, is evolution.

What is a mutation? A mutation is a change in the genes of an organism. Genes code for proteins, which are important for supporting your cells and helping them carry out biological tasks. This code relies on a very precise sequence of bits called bases, organized into the double helix of DNA. When DNA is copied during cell division, the sequence of bases has to be perfectly preserved so that each daughter cell can carry out its functions correctly.

The copying process isn’t always precise. Mistakes can be made, and despite your cells’ best efforts for identify and correct these mistakes before they become permanent, some slip through. They get copied into the next generation of cells, and so on, and so on.

So what happens when a cell’s genes become mutated?

In some cases, nothing. Each human cell contains a lot of DNA that doesn’t seem to code for anything in particular. This DNA may be an evolutionary relic, or it may have some function that is not yet understood. In any case, a mutation occuring in this “junk DNA” doesn’t affect the cell very much at all. Some mutations are harmful to the cell, especially if they prevent the production of a protein that the cell needs to produce energy. Occasionally, though, a chance mutation occurs that is actually beneficial to the organism. These mutations give rise to the traits that make an organism’s offspring better suited to survive and reproduce.

“Good” mutations are very rare, which is why evolution can be such a slow process. But if you have enough organisms in one area competing for survival, this increases selective pressure for beneficial mutations. Remember: mutations are random, but the processes that single them out for proliferation are not.

What is genetic drift? Genetic drift is related to the random nature in which alleles are distributed during reproduction. Remember when I said that we all have two copies of each gene? When your body makes sperm or eggs, each future you gets only one copy of each gene. Half of your gametes (sperm or egg cells) will carry one copy of each gene you have, and half will carry the other copy. The actual traits that show up in your children depend on the combination of half of your genes with half of your mate’s genes. It’s sort of like a genetic lottery.

Imagine that there are only four people on Earth: two men and two women. They are all healthy and of reproductive age. They pair off to mate, and each couple gives birth to two children in due course.

Now each parent carries two copies of the gene that determines earlobe shape, and that gene comes in two varieties: dangly or attached. For the sake of argument, let’s assume that each one of the parents is heterozygous (meaning they carry one attached and one dangly allele). Because of the way that alleles interact, the parents will all have dangly earlobes, but they have the potential to give birth to children with attached earlobes.

When their children are conceived, each child can receive either two dangly alleles, one dangly and one attached allele, or two attached alleles. It’s completely random. In a huge population, you’d expect twenty-five percent of the offspring to get two dangly alleles, fifty percent to get one of each, and twenty-five percent to get two attached alleles. But in very small populations, the laws of probability don’t necessarily apply like you think they should. It’s entirely possible that every single child could receive only dangly alleles, and the attached allele would completely disappear from the population after the parents croak.

Genetic drift becomes less important in large populations, but it can play a huge role in the future evolution of a species if that species is ever reduced to a dangerously low population. Just one more reason to be concerned about the conservation of threatened species. But I digress.

What is gene flow? Gene flow happens when separate populations of an organism are able to exchange genes. If the populations were completely isolated, genetic differences would accumulate over time until they became separate species, no longer able to interbreed even if they were re-introduced to each other. But if genes can move from one place to the other, the separate populations might be prevented from evolving into distinct species.

Imagine bird populations living on opposite sides of a mountain range. Their environments are remarkably different; one lives in a lush, semi-tropical jungle that is constantly nourished by rain; the other lives in an arid rainshadow desert. Faced with very different challenges, they may start to evolve apart – to form distinct species. But if there are mountain passes low enough to allow the birds to mingle, their interbreeding might keep the genomes from diverging enough to form different species. In a way, gene flow can hinder the formation of new species (although it still serves as an agent of evolution because it allows allele frequencies in a population to change constantly. Remember: evolution is not just about one species changing into another, although…)

What is speciation? Speciation is simply the formation of new species. The traditional definition of a species is a group of organisms that is incapable of breeding with another species to produce viable, fertile offspring. Of course there are a lot of gray area surrounding that definition where ligers and camas lurk. Nature so seldom conforms to our need for rigid definitions.

In any case, new species can form whenever populations of the old species are separated and prevented from sharing genes. Over time their genes diverge and their traits change. Over millions or billions of years, little differences become big differences. Entirely new groups of organisms arise to fill in every nook and cranny of habitable space on Earth. Four billion years later, you have an incredible diversity of life brought about by the fact that genes can change and survival is a constant struggle.

So yeah…all of these things are related to evolution. I can’t imagine why anybody would suggest otherwise, unless they were backed into a corner by mountains of evidence but still could not bring themselves to admit that evolution is real.