User blog comment:Lord Loss/Monster Hunter Theory... Blog/@comment-4212769-20120302173919/@comment-1011548-20120310100348

I'm pretty sure Charles Darwin never made a distinction between micro and macro evolution. In fact, I have heard that both are terms invented by the intelligent design crowd to try and confuse the issue, but as that was something I read on the internet I'll leave that particular argument for another day.

Anyway, as I understand it, macroevolution is the accumulation of lots of small changes until the species is notably different from an ancestor. When did this become disproved? That's basically what evolution is! Saying that it doesn't happen is like going up to a history professor and saying "All this stuff you've been teaching us about the Roman Empire is bollocks, I've never seen a roman and therefore they didn't exist.".

Democide's ammendment to deviljhodude's explanation is basically correct. Let's say you take the entire population of an organism, and split them up into two seperate geographic locations. Dogs, for example. The group that lives in wide open fields we'll call Dog A (and lets say this is where they were living originally) and the type that live in the mountains we'll call Dog B. Assuming they don't die out, the Dog Bs will adapt to survive in the mountains (gene mutations that encourage favorable characteristics will be passed on). For example, they might grow thick fur coats to cope with the cold, strong muscles for bounding around the rocks, acute vision to deal with the glare on the snow. Dog As prance around happily in the fields, having a wonderful life, but they'll still evolve; perhaps sharper senses to detect prey, keener vision, more streamlined bodies for chasing after prey. The dogs would now be Dog A1s.

Then some human comes along and says: "Ah, look, the dogs that live in the mountains are clearly the evolved form of these dogs running around the fields." That person is wrong'. Dog A1s and Dog Bs just share a very decent common ancestor; the original dogs scampering around the fields.

If you want a better understanding of how evolution works, I can't recommend 'The Greatest Show on Earth' by Richard Dawkins enough. Great book; witty, informative, with excellent explanations and clear metaphors.