I think I'll try this as a separate topic from the evolution thread, at least at first. We can merge it later if we have to.
It's a well-known fact that languages evolve. For example, English descended from Middle English, which descended from Old English, which descended from Germanic, which descended from Indo-European. Likewise, Spanish descended from Vulgar Latin, which descended from Old Latin, which also ultimately descended from Indo-European. Naturally, this is somewhat analogous to a species evolving into two different later species.
Although it would be folly to assume that the processes of linguistic evolution and biological evolution are exactly the same, I think the parallel is nonetheless illuminating. Very tiny shifts in pronunciation and grammar end up producing very different results over the years, even over a relatively short period of time. English today is nothing like it was 1000 years ago -- a short time period in the grand scheme of things.
But, to be fair, English did borrow many words from Latin in that time, losing many of its own words in the process. A more fair comparison might be between Spanish and Latin, since Spanish did not borrow such a large number of words from other languages and therefore evolved with much less interference. Of course, those are still two very different languages, even though much of the vocabulary is recognizable. For example: Spanish has articles; Latin does not. Spanish uses function words much more than Latin does. Latin has an elaborate declension system for nouns and adjectives, requiring you to change the ending of the word depending on its function; Spanish has lost this system entirely except for grammatical gender and for a few pronouns. There are many sound shifts: the suffixes -ātum and -itum have become -ado and -ido; -us and -um have become -o (hence so many Spanish words ending with -o), and many more. The way an adjective is turned into an adverb is different. And so on... so many changes have occurred that today a speaker of Latin and a speaker of Spanish cannot understand each other unless they have studied each others' languages. And each of these changes happened only one bit at a time, slowly and gradually. You can even see signs of language change happening today if you know where to look. But if you don't know where to look, you'd never know it because the process is so subtle. It's rather like trying to watch the hour hand of a clock move. It does, and you know it does, but you can't see it happening just by looking directly at it.
Hence, microevolution in languages causes macroevolution. (The point emerges!) I don't see why that principle wouldn't apply equally to biological evolution -- albeit with much more gradual changes over much larger time scales. Sure, there could be a reason why it wouldn't, but unless we have that reason, it's a decent assumption.
Thoughts? (And first poster who says only "tl;dr" gets hit with a baseball bat.
)
- Kef