The little things in life

There’s nothing like a little bit of detail to give you a whole new perspective on a situation.

A colleague recently provided a good illustration of this in a course I’m taking: if I were to say, “this morning I got out of bed and shot an elephant in my pajamas,” you would have a certain image in your mind. But if I followed that up with, “why he was wearing my pajamas I’ll never know,” your first interpretation would immediately evaporate and you’d now be working with an entirely different image.

A little piece of additional information can have a dramatic effect.

The same can be said about evolution.

Many people still resist this scientific explanation, thinking it just takes too many changes, or the changes need to be too big, to produce any meaningful results. If they actually looked into this, rather than simply parrot what they’ve heard other people say, they might be surprised.

I came across a photo on another blog site which makes a powerful argument for this …

 

… it shows two views of tree branches bearing leaves and berries as seen by two different birds with slightly different abilities to perceive light.  Before explaining what’s going on here, a little background might be helpful.

Vision involves converting light rays from objects into electrical signals that your brain can then decode and interpret.  That light-to-electricity conversion is done by proteins in your eye which absorb the light rays and turn them into a chemical change which in turn produces an electrical signal. It’s important to know, though, that these proteins respond better to certain colors of light, and much less so to other colors.  We humans have three different kinds of these proteins, which respond best to either green light, blue light or red light, and our brain stitches these three different signals together into the vibrant and colorful world that we perceive.

The top photo shows what would be seen by a bird that can perceive only green light rays.  That bird would have very little problem landing on the branches and distinguishing the berries from the leaves without even touching them, since all three parts of the tree have very different shapes and textures. That bird is reasonably well adapted for a life of flying from tree to tree and finding food to eat.

The bottom photo, however, shows what would be seen by a bird that can perceive both green light and red light.  This new ability makes life so much easier for the bird: not only do the branches stand out better, but more importantly the berries just jump out as distinct from the leaves. Even more, the bird can now easily discern how ripe each of the berries are: notice how some are still quite green, others are bright red, and many are somewhere in between. This bird won’t be wasting any time on the less nutritious berries. You have to agree that birds with this ability are going to be able to compete much better than the ones that see only in the green range of colors.

A tremendous advantage in a world based on competition.

A tremendous advantage caused by two simple genetic changes which happen all the time.

The first change is a gene duplication. When the cells create copies of their total package of genes to hand off to their daughter cells, they sometimes experience a genetic hiccup, and copy a whole stretch of DNA twice or three times (or even more). That actually happens quite often.

This doesn’t create any problem: those daughter cells will simply now have extra copies of genes producing the very same proteins.

But it does create an opportunity. One or another of the duplicate genes can later pick up a second mutation without any risk. If the second mutation destroys the protein, the cell still has at least one extra copy to continue producing the necessary protein. Sometimes, however, the extra mutation can lead to a slightly different protein with a new function.  This is exactly what happened with the light-sensing proteins: a minor change made it insensitive to green light but now sensitive to red colors. Another duplication event followed by a coding mutation produced a third protein that can detect blue colors. There’s now an intriguing possibility that some women have developed a fourth protein that allows them to see in four colors.

A similar duplication/modification event in genes for certain enzymes allows the cells to digest entirely new types of food molecules, opening up a whole new avenue of resources to exploit, ones unavailable to their competitors.

Gene duplication/modification for the proteins that create the electrical signals … molecules that I study in my laboratory, called ion channels … lead to entirely new kinds of electrical signals that nerve cells can produce, which in turn is crucial for the complex signalling that goes on inside our brains.

Other gene duplication/modification events give you the diversity of antibodies in your blood.

The different receptors in your tongue and nose which allow more profoundly sensitive abilities to smell prey, predators, mates and dangers.

The list is endless. There are thousands of examples of this happening in our genome. Little changes that can actually confer big advantages.

Interestingly, there are also thousands of examples in our genome in which the gene duplication/modification event failed to produce a useful protein … a genetic dead-end. That observation is hard to explain from an Intelligent Design point-of-view, but makes perfect sense within Darwinian evolution.

It’s the accumulation of these small changes which leads to ever more complex and diverse forms of life.

So why the resistance to this simple idea that explains so much about biology? For many, acceptance of evolution theory automatically demands rejection of faith. But what if the Bible never intended to be the scientific answer to the question of how we came to be?

The Bible was written at a time when the Akkadian, Sumerian, Babylonian, and Egyptian empires ruled the ancient world for thousands of years, before Hebrew became a language (Abraham was thoroughly Babylonian!) or Israel became a nation. They represented the cutting-edge of science and the epitome of culture. Their thinking determined the zeitgeist of the world at that time.  And they all referred to the ancient primeval waters which were separated by pantheons of gods who fought cosmic wars, and who created humans from clay to do their work and bring food sacrifices to them. Their gods also mixed something in with the clay – their divine breath, their tears, drops of their blood, or the flesh of a god they’d slain – in order for these humans to be somehow different from the other animals.

The Hebrew writers took those stories and turned them upside-down. They wrote of one single God, who created people in a garden full of food, and told them to have sex and make babies, and enjoy walking in the garden with him. Not because they believed this was the scientific explanation of how protons and electrons came to be, and species speciated. But rather to correct what they saw as a distorted theology.  It was written to a different group of people and meant to address a different question, or at least the same question from a completely different angle.

Scripture and science do not need to be viewed as conflicting: they can be complementary. They can say different things about a given question because they approach the question from different angles.

Scientists used to argue about whether light was a particle or a wave, two completely different ideas. Until they realized that both statements are true.

Newtonian physics was a powerful tool which explained the trajectories of cannon balls and the orbits of planets around the sun, but completely failed to explain trajectories and collisions at the atomic scale. Position and trajectory no longer had any real meaning: it was possible to quantify one but not both. A given object could be everywhere and yet nowhere at the same time. Heisenberg’s Uncertainty Principle took over. Then quantum mechanics stepped in and solved that problem. But quantum mechanics completely fails in the other direction: at large scales. It cannot possibly be used to launch a Rosetta space probe to intercept a comet which would eventually come to brush past Earth ten years later.

Seemingly conflicting ideas or approaches, both of which are correct and useful, but only as long as one understands their limitations and the contexts under which they operate well.

Why not view scripture and science in the same way?

Tell me what you think …

 

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