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?”