If I had to reduce evolution down to its most fundamental essence, I would have to describe it as reproductive differential. Simply put, whoever leaves the most offspring wins. It doesn't matter how strong a creature is or how fast or how clever; if it doesn't leave any offspring then its advantages die with it. If a creature is a good enough hunter, fast enough to escape predators, and appealing enough to attract a mate, then it will hopefully have offspring that will inherit its advantages. The next generation begins the race anew. The fit will live to reproduce; the unfit will die. Eventually, all the characteristics not suited to a particular environment will be removed from the population and the species will become well adapted to its surroundings.
The judge that helps decide who lives, who dies, and who's genes will be passed along is a cruel mistress by the name of Natural Selection. She's an impartial judge and is only concerned with one question: does it work? Every detail of every creature is judged on how well it works: the shape of its teeth, the color and length of its hair, how fast it can run, how high it can jump, and even the shape of its eyes will be judged. If a trait passes the test, the creature lives to be tested again. Hopefully, it lives long enough to pass its traits on to the next generation. If a feature fails, its host dies. If the host died before leaving any offspring, then the unsuitable trait died with it. The trials continue unceasingly: what works lives – what doesn't work dies. Over time, natural selection works remarkably well and a species becomes very well adapted to its environment.
To help visualize natural selection, I like to use the example of dogs. Most people are familiar with dogs and know that they are a very diverse group. Dogs can have long or short hair, be a variety of colors, be sleek or muscular, and can range in size from the very large mastiff to the very small chihuahua. Dogs represent a kind that includes not only domestic dogs but also wolves, foxes, coyotes, and dingos. Suppose I took a pack of mutts containing dogs of all sorts, then released them into the wild. Natural selection would immediately begin her work. The dogs that lacked the instinct or ability to hunt would quickly starve. In a wooded environment, dogs with brown fur might be better camouflaged which would help them sneak up on prey or hide from larger predators (like pumas or bears). In a snowy environment, lighter colored fur might be more advantageous. Their hair must be long enough to give them warmth and protect them from sun burn yet not so long as to overheat them or harbor disease carrying insects. Their bodies should be large enough for them to overpower prey but not so large as to require more food than is available in that area. Everything about the dogs will be tested: their sense of smell, their eyesight, their hearing, even the shape of their ears. The dogs that have the features best suited for that environment will tend to survive longer and have more pups; the dogs not well suited to that environment will tend to die sooner and have fewer pups.
Over several generations an interesting thing occurs – the pups will all begin to all look alike having similar size, hair length, color, patterns, etc. When all the dogs possess enough traits in common that they can be identified as belonging to the same group, we could call it a new species.
When species are adapted to their environment, they become specialized and less diverse than their ancestors. While the dog-kind is very diverse, dog breeds (like Irish Setters) or dog species (like Canis lupus) all tend to look alike. Because breeds or species are specialized, they are less able to adapt to new environments. A snowy environment, for example, might prefer white hair. However, if I released only Irish Setters into a snowy environment, they will only have red pups and so could not adapt as well as a diverse pack with lots of colors could.
This is a limitation of natural selection. It can only test features already present in a creature. Suppose I had released my hypothetical pack into an environment containing a lot of blue. Blue is fairly common in nature: there are blue plants, birds, insects, reptiles, and fish. If the environment contained a lot of blue, a blue dog might have an advantage. However, there are no blue dogs and natural selection is not able to “add blue” to the features it selects. Natural selection works only by quickly removing the unfit from a population which allows the more fit to continue a while. That's all it ever does.
This is bad news for evolution. Evolutionists notoriously conflate natural selection and evolution as though they are the same thing. They are not. Here's a quote from Science Daily that I've used on my blog before:
Countering the widespread view of evolution as a process played out over the course of eons, evolutionary biologists have shown that natural selection can turn on a dime -- within months -- as a population's needs change
Did you notice how they shift from saying “evolution” to “natural selection” in the same sentence? Whenever I cite this quote, the correct response from honest evolutionists should be to say that Science Daily should have been more careful with its wording. Instead, they hem and haw and make excuses for Science Daily. Have they no shame? Even though I know they know the difference, they are so jealous of the term “natural selection” that they cannot bring themselves to draw a clear line between it and evolution. They prey on ignorance and want people to believe that natural selection over time necessarily leads to evolution.
For evolution to occur, a population must acquire traits. For something like a reptile to become something like a dog, you would have to add hair. The imagined first-ancestor-of-everything did not have hair. Neither did it have feathers, gills, scales, skin, bark, bones, blood, nor organs of any kind. Just think how many features one would have to add to a bacterium to make it into a bird or birch. So evolution demands that populations ACQUIRE traits while natural selection can only REMOVE traits. Natural selection is the opposite of evolution.
In a recent post, I talked about “microevolution” and “macroevolution.” In my example of dogs, there are some people who would call natural selection acting on the traits present in the pack, “microevolution.” If the pack eventually earned the moniker of species, some people would say that's “macroevolution.” It's a lie because these dogs have not evolved in the least since nothing was added to the population. Evolutionists would have us believe that evolution is “change,” these dogs “changed,” therefore these dogs “evolved.” What's more, they argue that over millions of years, these same types of changes could turn these dogs into something that is not a dog! It's nonsense. It's poppycock. It's foolishness! Creationists should not even give ear to such ridiculous ideas and we certainly should not participate in this lie by using these terms ourselves.
There are many things that have been associated with evolution that really have little to do with evolution. Evolutionists often invoke terms like “natural selection,” “variation,” and “millions of years.” While it's true that evolution requires these three things, by themselves they could never lead to evolution. The only leg upon which evolution could stand is “mutations.” Mutations is the real hero of the evolutionary fairy tale. Mutations could maybe turn a frog into a prince but natural selection and time cannot.
I'm going to talk about mutations more in another post. In the meanwhile, creationists need to recognize the difference between natural selection and speciation (which really occurs) and evolution (which does not occur). We need to correct evolutionists who place a false importance on some “change” observed in a population. And we need to stop calling natural selection evolution.