Defining Evolution 2: The Tree of Life

It was another beautiful Thursday night at Danny’s Bar, Grill, and House of Rabblerousing, and by “beautiful” I mean “spent consuming mass quantities of root beer, nachos, and various other foods which are pictured on those posters warning one of the threat of heart failure.” With me at the round table in the corner by the dart board were my friends Bill, Carl, Tom, and Captain Blue Beard. NACHOS logoWe meet regularly as a sort of support group for men with jobs and whatnot. Giving each other a leg up dealing with the acquisition of the old American Dream. We usually banter about the week’s adventures, counting the death toll as sales clashed with marketing, or recounting the destruction done to one’s stain resistant carpet by one’s own pint sized flesh and blood, and of course we often have lengthy discussions about any movie which was based on a comic book or graphic novel. However, this week we have a prearranged topic of discussion for the enlightenment and education of all the western world.

Just last week I was all set to begin another row with my friend Carl over the historicity of Darwinian Evolution, when our friend Bill made a very wise suggestion that we first endeavor to define the term. After all, how can Carl say that Evolution is, or I say evolution is not true if neither of us can define what it is? We might not even be talking about the same thing, like that time we argued for two hours about the quality and entertainment value of the Batman movie, when it turns out I was talking about the one starring Adam West (“Some days you just can’t get rid of a bomb!”) and Carl was talking about the Christian Bale one (“Swear to me!”) and Tom was talking about the Michael Keaton movie (“Did you ever dance with the devil in the pale moonlight?”) and Captain Bluer Beard was talking about the Tic animated series, which really shows how little he was paying attention during that particular conversation.

I opted to begin with my favorite educational tool- visual aides.
“My research has uncovered a huge collection of variations on these two images,” I said producing the Darwinain Tree of life, and the monkey to man parade which has gone by many names since first being published, and even variations via parodies.March_of_Progress2 “They all show the gradual progression from bacteria to worm to fish to lizard to rodent to man to Captain James T Kirk through slow, gradual changes over millions of years. This is the story evolution tells, and the map of those changes over time is what we call the Darwinian Tree of Life.”evolutionary history to shatner2 copy

“How’s the monkey parade the same as the tree when all it has is monkeys and men?” asked Blue Beard.

“The tree is meant to show a general history of all life on earth,” replied Bill, “where as the monkey parade is meant to indicate one chain of links on one branch near the top of the tree.”

“Right,” said Tom. “Every branch on the tree diagram would, hypothetically, branch out into a wide range of variations which, individually, could look like the monkey parade. Of course none of these trees is entirely complete, because they would require the depiction of millions of species with millions and millions of intermediate forms (aka: Missing Links) between them, and frankly, no one has that much blank paper or free time on their hands.”

“When the tree branches,” explained Bill, “that means an existing animal kind has diversified into two distinct groups. For an example I think we can all agree would be an evolutionary branching,” he said pointing to a point on one of the tree pictures, “imagine if worms divided into two groups- one of which remained worms of various kinds, and the other of which became fish.”

“There would be a lot of steps involved with the addition of a lot of genes,” I suggested. Genes for eyes, genes for gills, genes for fins, genes for a swim bladder, genes for saying ‘bloop bloop’ in children’s books where the principle characters are animals who can talk, etc.”

“So when worms evolve into fish,” Bill continued, “that doesn’t mean EVERY worm becomes a fish- it means that SOME worm gets a beneficial mutation which SOME of its offspring get, and some of those descendants get other beneficial mutations added onto that one- and this happens over and over until the worm has the genes for eyes, and thus eyes and also gills, and whatever other parts make it a fish.”

Blue Beard grasped his root beer and said, “Somewhere in the middle I suppose it’s part fish and part worm, which means Disney princesses are wrong- a Wish is a Fish that’s still part Worm. You can’t do that upon a star.” He drank thoughtfully for a moment and then added, “Well, you could, but it would be disgusting.”

I turned to Carl. “You’ve been quiet, old friend. What are your thoughts so far?”

“It’s no different than what I said last week,” he replied. “Evolution is a broad category which pertains to living things changing over time and these pictures are a depiction of the history of those changes.”

“Once again I have to argue that your definition is too vague,” I replied. “Undoubtedly a lot of things can happen to plants and animals which do NOT cause the growth of the Darwinian Tree of life and creation of new species or kinds, such as being eaten.”

“Falling into a volcano,” offered Blue Beard.

“Having a light breakfast, or getting a haircut,” added Bill.

“But none of those things should be included in the definition of “evolution,” I said, “because none of them affect the tree of life by causing it to grow and develop new species, kinds, orders, classes, etc.”

“This is why I think it’s good to present the tree of life in its broadest terms,” interjected Bill. “Bacteria to worm to fish to lizard to rodent to primate to us. There are a lot of things which can happen within a kind of animal which will not grow the tree in this manner. Take the dog kind for instance. Wolves can and did become, over time, Collies, Labs, Terriers, Poodles and Chihuahuas. These are all different, but they are all DOGS.”

“Wolves giving rise to other dogs IS evolution!” insisted Carl. “That’s decent with modification. It’s a textbook definition of evolution!”

“It’s true,” said Tom. “I have that textbook.”

“That may be,” said Bill, “but we can’t say for certain until we agree on a definition.”

“What’s wrong with saying evolution is decent with modification? If it’s good enough definition for college textbooks it should be good enough for us!”

“Same as before, Carl,” I answered. “Modification is too vague a term. It can mean ANY kind of change, and as we’ve all acknowledged, change can be good, bad, big or little, but not every kind of change will cause the tree of life to grow. Extinctions will change the tree, but only by killing off a limb which was already on the tree. We need to explain how the limbs got there in the first place.”

Carl took a swig of rootbeer and said, “I think we can agree that wolves becoming every kind of dog, from Mastiff to Chihuahua is evolutionary modification. That certainly grows the tree.”

“Sorry, Carl,” I replied, “but I don’t think so. Each kind of animal can spread out into a vast shrubbery of variations on the kind without ever adding a branch onto the Darwinian Tree. This is part of the Biblical Creation model of life on earth- the Creation Orchard. Dogs give rise to different dogs and fish give rise to different fish, but fish never give rise to dogs.”

“But that is exactly what Darwinian evolution claims,” said Tom “that fish DID give rise to dogs. Through a lot of steps I mean.”

“That’s right,” answered Bill. “What must make Darwinian Evolution distinct, and what must make a mechanism of evolution a mechanism OF EVOLUTION is the ability to make a NEW kind of animal with NEW genes for NEW features and behaviors. That’s why it’s wise that we consider those big changes, from fish to wolf, and not the smaller changes like wolf to poodle.”

“Also,” said Tom, “there has to be a connection of common ancestry into the past through LOTS of kinds reaching back to the bacteria at the base of the tree. Apparently we all agree that poodles have a common ancestor with modern wolves, but we need to define evolution so poodles and wolves and us all have a common ancestor which is a fish.”

“Well said, Tom!” offered Blue Beard. “If Rent-A-Friend here is right, then the fact that Poodles and Chihuahuas have a common ancestor which is a dog isn’t merely Darwinian. It’s also Biblical. Somewhere, if evolution is true, wolves share a common ancestor with fish and with cabbages.”

“Cabbages probably branch off earlier,” suggested Tom, “but in terms of the full story, yes. Evolution would claim that somewhere on the tree is a common ancestor of wolves and cabbages. In fact, of ANY two living things on earth.”

“Let’s consider the genetic component,” suggested Bill. “Evolution REQUIRES the creation of new genes. Existing Genes being shuffled so that there are new combinations of already existing genes is not Darwinian. Already existing genes being lost over time is also not Darwinian.”

“Why not?” asked Tom. “When you shuffle genes you make new combinations that didn’t exist before. Isn’t that making new genetic information? Isn’t that evolution?”

“If you have a population of bacteria with, say, 1000 genes between them,” said Bill, “and they share those genes with each other to make new combinations of genes over and over for billions of years, not a single one of them will ever gather the right combination of genes it would take to make a moose.”

“I think I can explain this,” said Blue Beard. “Tom, do you know what the Archduke of Hearts card looks like in a standard deck of poker cards?”

“No.”

“Course you don’t. It don’t exist.” Blue Beard produced a deck of cards from inside his coat and spread them out before us. “No deck HAS an Archduke of Hearts. Now, get a thousand monkeys, and give them each a deck of poker cards. Lock them in a room and make them shuffle those cards for a thousand years,” he shuffled them to demonstrate and I imagined him as a monkey, which was not hard to do, “and do you know what you will have at the end of it?”

“What?” asked Tom.

“You’ll have a room full of dead monkeys. So don’t actually do that. What you will NEVER have is a deck that contains the Archduke of Hearts. None of the decks contained it when they started shuffling, and none of the decks will gain it BY shuffling.”

Bill gestured to our pirate friend with his root beer. “So in your analogy, the Archduke of Hearts is a gene which is required to make a moose which the bacteria do not have. Say, the gene to make antlers.”

“It probably takes more than ONE gene to make Antlers,” complained Carl.

“But let’s pretend it only takes one, just to keep it simple,” Bill said.

Secretly I was disappointed that Blue Beard didn’t follow up with a magic trick, but his point was well made. In order to make the tree grow from worm to fish to lizard, there needed to be the creation of new genes, not merely a rearranging of genes which already existed. “Let us remember” I said holding up the pictures of the Tree of Life, “that evolution is a story which tells us that bacteria gained new genes over and over until it became worms which became fish which became wolves, and all of these steps require additions to the genome.”

Carl snorted with disdain. “The bacteria to worms to a man walking around town is an old creationist song and dance that no evolutionist argues for.”

I paused for a second to make sure I had heard him right. I looked at the picture of the evolutionary tree I was holding, and then I held the picture of the tree up to Carl. “I got this from an evolutionary source Carl. I have six of these,” I held up the other images of the tree of life, “all from popular, evolutionary sources. I think perhaps you had better explain what you mean by “Evolution” if you don’t mean bacteria to worms to man. You may mean something so far removed from Darwin that you shouldn’t even be using that word.”

“My point,” pontificated Carl with a sneer, “just to clarify, is that your bug to man canard is such a small part of the story that it’s a cartoon. It’s the kind of thing that makes otherwise literate people say “my grandpa weren’t no monkey!” It’s a straw man used to insinuate something that is only partly true but easily dismantled.”

“The Darwinian Tree of Life is a Straw Man?” I said, perplexed. “Carl, if you are rejecting the Story Darwinian Evolution is meant to tell, then what is it you are meaning by “Evolution”? If the alleged history told in these trees is not what you believe Darwinian evolution teaches, then present what YOU think it is.”

Carl drank some root beer and stared off toward the kitchen, no doubt anticipating the arrival of Wendy with our mountain of Nachos. “To be frank,” he said in the direction of the kitchen, “I’m not interested in your definitions of evolution or genetic variation. They mean specific things to working evo bio folks and I’ll stick with those definitions.”

“To be frank,” said Bill, “I am interested in your definitions, at least of Evolution and of how you think new genetic material is created, since that seems to be the central point of this particular discussion.”

“What is taking those Nachos so long?” said Carl. “I barely had time for lunch. I’m starving.”

“Carl,” I said, also secretly hoping the nachos would come soon, “why not just answer the simplest and most central question- what is evolution? Surely if you know it’s true, you must know what it is? Surely if you have written a sixty part blog series defending it as truth, you must, SOMEWHERE in all of that dogma, DEFINE what it is you are defending?”

“You wrote a SIXTY PART BLOG SERIES on evolution?” asked Blue Beard, incredulously.

“Yes, said Carl. “I had a lot to say on the subject.”

“Except what it is, apparently.”

“Shut your blue entrenched mouth,” growled Carl.

“I’ll be shutting my blue entrenched mouth around some Nachos, thank you lad.” Blue Bear gestured toward the kitchen with his root beer. “Here comes Wendy!”

And with that the Nachos had arrived and we were soon drown out by the sound of our own eating and then the sound of a local cover band doing a truly pitiable rendition of Lucy in the Sky with Diamonds. Our conversation would have to continue the following Thursday.

Happy Nachos! And thanks for letting me be your Rent-A-Friend.

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