Human origins: ‘who’ versus ‘how’

Only hours into our marriage and we were already fighting! And with knife in hand, no less!? My beautiful wife and I, roughly thirty years ago. Standing in front of our wedding cake, posing for the classical picture while dozens of cameras were snapping pics. As the knife touched the cake, I heard a distinct tapping sound. I leaned to my wife and jokingly said “The cake is fake”. Her confident response: “No, my mom made it”. The scientist in me took a step back, and then I replied “Listen”, while I knocked on the top of the cake a few times, each time evoking very distinct percussive reply. Again: “No, my mom made it”. “But listen!” “No, my mom made it”. “LISTEN!” “No, my mom made it”. This went back and forth several times while the cameras continued to flash, and I got increasingly frustrated that she wasn’t ‘listening to the data’. We have a picture of the two of us examining the cake to make sense of it.

In the end, we were both right. Her mom did make the cake, but the cake decorator had put a plastic base on top of some of the layers to prevent the whole elaborate structure from collapsing in on itself.

Thirty years later, that kind of argument continues. Not between her and I, but between scientists and theologians, trying to make sense of how life came to be on earth. With the same sort of replies being exchanged: “Just look at the data” versus “No, God made it”.

We have to be careful to not entangle two different questions: (1) “who/what was behind the making?”; versus (2) “how was it made?” Many mistakenly turn these into one question, but that unnecessarily complicates and biases the problem. If one sets aside certain presuppositions — certain interpretations of the Biblical text — it’s equally possible that God made it, but used evolution to do so.

Why do I feel it necessary to even call this into question and make this point? In doing some research for book #2, I’m seeing how much humans have the exact same physiology as the other animals, and use the same genetic coding. In fact, our own genetic code is peculiarly similar to those of the other primates (chimanzees, gorillas, orangutans) as well as to Neanderthals and Denisovans.

One simple explanation — based on observed scientific data but contradicting the Biblical text — is that we descended from a common ancestor after a series of modifications.

Another simple explanation — based on one interpretation of the Biblical text and contradicting the observed scientific data — is that we are a separate species which God designed and created from beginning to end, but used the same design features that he used for the other animals.

Many refer to these as the Common Descent and Common Design models.

How does one choose between these two very different models? How would you actually test the design hypothesis? Unless we actually find a cell with God’s name scrawled on it, or “Made in Heaven” stamped on it, how could we actually distinguish something that arose by a gradual change versus a sudden snapping of the fingers? A scientist will ask: “What predictions can we make based on these two fundamentally different models?”

A slow gradual change would involve building new features on top of old ones. Friends of ours have renovated a small old stone school building, turning it into a beautiful house. You can still clearly distinguish the old parts from the new, and the different building materials used. Buried in the walls there may still be pulleys and cables which rang the old school bell, or possibly old lead pipes and aluminum wiring from a time before the building codes were updated to copper. In the same way, the evolutionary model (Common Descent) would predict that our bodies should still reveal certain old designs. Remnants of old mechanisms which are no longer needed, or newer better ones built on top of them.

And if we were designed from scratch, there should not be places where we see half of an old design and half of a new design. All the parts should be in their proper place and make sense. And if designed by an omnipotent omniscient intelligence, then everything should work perfectly, and make perfect sense (I only add this sentence to deflect comments from owners who bought a brand new house that had all kinds of problems).

How do those two predictions pan out when we look closely at the design of our bodies.

On the one hand: yes, we are indeed “fearfully and wonderfully made “.

But on the other hand, we still find remnants of old mechanisms that make sense in the Common Descent model but not in the Common Design model …

… tiny muscles on the ends of the hairs of our skin, which lift the hairs when we get cold or when the fight-or-flight response kicks in (when someone jumps out at you from the bushes late at night). That made perfect sense in animals who had only their fur to keep them warm in the dead of winter, or who needed to look bigger when confronted with a predator or a competitor. But those self-lifting hairs do nothing for us humans.

… tiny muscles which are loosely attached to our ears, and which a few people can still use to wiggle their ears or their scalp. These muscles are useful in cats and dogs and other animals that turn their ears toward sounds, but primates and humans have learned to simply turn our heads so we can get our more perceptive eyes on the source of the sound.

… nerves which suddenly retrace part of the path they took in the developing embryo, as if they missed their target. The nerve has genetic instructions to follow certain landmarks within the developing embryo to lead to its intended target. “Go straight down the neck, take 10 steps past the lungs, hang a left at the aorta and go a few more steps till you come to the kidneys, then … “ But as the body shape and design changed over millions of years, the target moved a couple millimeters, and it was simpler to just add a small diversion at the end of the journey — “take one half-step to the left” — than to give it a whole new set of landmarks. The problem is that as the target continued to move, the small diversion at the end became an increasingly bigger side-trip. But it was still easier to simply adjust that last line of code — “take two steps to the left”“take three steps to the left”“take four steps to the left” … and so on — than to wait for a mutation which gave a completely new more streamlined set of instructions. (just Google ‘recurrent laryngeal nerve’ if you want the whole story on this one.)

… genes for making tails at the bottom of our spine. These were useful to animals who swing through trees, but not to their descendants who started walking on the ground. These genes are normally turned off in us Homo sapiens, but a few very rare individuals are born with tails up to 12 centimeters long (5 inches), which can then be removed surgically.

… many hundreds of genes for proteins which detect subtly different smells (odorant receptors). A very large number of these are never used in humans. Those genes are needed in animals that rely heavily on being able to smell their prey and/or predators. Our dogs laugh at our pathetically poor sense of smell. It doesn’t make sense that we’d be created with all those genes that are never used, but it does make sense that we inherited them from ancestors who needed them.

… genes to make the major protein in chicken eggs, or to make our own vitamin C, or many other functions, all of which are present but useless in us humans.

… the blind-spot in our eye caused by the eye’s major nerve disrupting the light-sensing layer of cells. That nerve could equally have done its job of accessing those cells from behind. This is how the octupus solved the exact same problem after its ancestors and our own diverged down different evolutionary paths. But by penetrating through the layer in our eyes and then spreading out across the front of the retina, it reduces visual resolution and creates a blind spot.

… the process of childbirth, which too often resulted in a horrible death for the baby (suffocation) and the mother (painful but fruitless contractions until she is literally exhausted to death, or bleeds to death). This was a huge problem until we came up with modern medical procedures (and is still a major source of mortality and suffering in third world countries). The problem stems from having to squeeze the baby’s head through the narrow pelvis of the mother. There’s no reason for a designer not designing a different pathway for the baby to get out of the mother … even another hole in the belly. It makes more sense that in the long distant past when mammals had relatively small brains, evolution just made a few adjustments to an already existing exit point from the mother’s body. But once humans came along with their much bigger brains, childbirth became a big problem.

… the muscle that wraps around our airways which does nothing good for us but only gives us asthma attacks (I studied this in the lab for 25 years).

I could go on about other apparent design flaws. But for me, the conclusion is clear: gradual change and evolution (Common Descent) make much more sense of the observed data than special creation (Common Design). To insist on the latter should make one wonder why the designer made us with so many flaws, and who seemed to construct a very elaborate ruse intended to misguide us.

That doesn’t mean we need to get rid of the designer. Maybe we just need to revise our understanding of how the designer accomplished it. Remember, there are two questions on the table: “who” and “how”.

In the end, my wife and I were both right. It was entirely true that “Mom made the cake”, but the making was a slightly more complicated event than we had originally realized.

Can’t both the theologians and the scientists be right on this bigger question of “how did we come to be?”

Let me know your thoughts.

 

To get a notice when my next blog post appears, “Follow” me here (upper left corner) or on Twitter, or “Friend” me on Facebook. And please share this article with your friends and colleagues.

 

Advertisements

2 thoughts on “Human origins: ‘who’ versus ‘how’

    • Hi Luke,
      Excellent illustrations – really helps to bring life themes and memes lay folks inherently know exist to a entirely different level of potential comprehension for them.

      Like

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s