Why Evolution works inside Ecologies

While everyone likes to watch shows about deer, bears, and wolves, there are also exciting examples of ecosystems in the microworld. The less glamorous gastrointestinal tracts of these science documentary superstars is also a great example of how the interplay between species plays out.Cattle actually offer a good example of what I am talking about. They require a set of microorganisms in their foreguts to break down cellulose into useable sugars. The life of the big mammal rests in the flagellum and cilia of the smallest microbes. When cattle are moved from their usual habitats onto feedlots they are fed a diet high in corn instead of their usual grasses. The corn is loaded with simple sugars compared to the long chains of sugars found in cellulose that have to be broken down for them. Corn is a powerhouse of energy, and it allows cattle to gain weight quickly. However, it also changes the ecosystem of the cow's foregut. They lose their normal symbiotic and commmensal microorganisms and have them replaced by nasty, disease causing microorganisms. This is why antibiotics are used in great quantities in feedlots.The ecosystem of the gut and mucosa are also a very cool and very accessible system to look at, IMHO.

Can you point to differences between closely related species that could not be produced by microevolutionary mechanisms?

I simply mean sharing a large percentage of DNA. This makes it a bit easier to compare sequences, that's all. Too bad you can't evidence it. You seem to think that simply saying something carries weight. It doesn't. Evidence carries weight. In the real world, mutations in each generation increase genetic diversity. This is what is evidenced. We also observe that with each generation, the human and chimp genomes continue to diverge, consistent with macroevolution.

It's wrong. Nature has already done the experiments for us. Mutations add diversity to a population over time, and isolated populations will diverge over time. That is what we see in nature.

They can and do contribute beneficial characteristics. Among the differences between us and chimps are the mutations that have produced beneficial adaptations in humans, such as our increased brain, upright stance with effecient jogging gait, fine motor skills in hands, etc.

It is all related. For example, a single mutation can lead to the acquisition of antibiotic resistance. This adds to the genetic variability of a population. When antibiotics are introduced to your GI tract, it kills off a ton of competing bacteria. Suddenly, that massive change in environment makes that mutation a windfall.Having Faith outright deny these simple known and understood facts makes it impossible to discuss ecosystems in such a way.

We observe mutations producing beneficial genetic changes. Concluding that the differences between the human and chimp genome are the product of the observed mechanisms of mutation is no different than concluding a fingerprint at a crime scene came from a finger instead of a Leprechaun. No faith involved since we are working from observed mechanisms. We observe that mutations confer beneficial phenotypes. One example that is fitting for this thread is the evolution of dark coats in pocket mice.Just a moment...Here is a picture of the black mice that evolved in an ecosystem that included dark lava, compared to their original ecosystem which was a light colored desert. Edited by Taq, : No reason given.

We OBSERVE that mutations are the cause of genetic changes. The black allele is a dominant trait. You would know that if you had read the paper that I referenced. Also, the black lava is much younger than the desert that surrounds it. The black allele is strongly selected against in the light colored desert to the point that even the dominant black allele can not be found in populations found any decent distance away from the black lava fields.This is not the case of a recessive gene becoming prominant. It is dominant, and it doesn't exist in the light colored population, and would not have existed for any appreciable time before the appearance of these black lava islands. The genetic evidence clearly shows that it is the emergence of a mutant allele in the recent past.Or perhaps you can tell us why the observed mechanisms of mutation could not produce the black allele.

It could change it drastically. Mice can transport seeds and "fertilizer" where it wasn't present before. This can produce new niches for plants, and other species that depend on them. However, these are probably going to be micro-ecosystems given the relative size of the lava fields.Like I said before, these are islands of lava. While not quite as drastic, this is like a new volcanic island rising out of the ocean with no other islands around for miles. What you will see is a dynamic interaction between the environment and species as the species evolve to take advantage of the newly opened niches.With the pocket mouse example we can also see how evolution of ecosystems is affected by geographic distance. There are actually two black lava islands in the study that are separated by hundreds of miles. There is simply no way for the mutations that cause the black allele to spread to the mice next to that other black lava island due to the strong negative selection in the light colored desert. Guess what? There are still black mice on that other black lava field, but they don't have the same mutations as the other black mice. Black fur actually evolved twice through different mechanisms at each of the black islands.