Okay, so a little background information:
Recently I've been thinking about how quite a few languages (talking mostly about IE languages here) appear to be 'simplifying' themselves over time, getting rid of cases and simplifying their conjugation systems. Obviously, these languages aren't truly 'simplifying' themselves. There is no doubt that Latin's case system, for example, is obviously more complex than, say, English's, but does that make English's grammar less complex? Where older IE languages like Latin and old English used inflection to convey meaning, modern languages like English and Italian use syntax and other means of doing so. These languages aren't 'simplifying' themselves, just becoming less synthetic and more analytical, it's not about complexity here.
But the trend is still undoubtedly there, modern IE languages are -as a general pattern- becoming more analytical, like how Italian has no cases, Latin had five, Proto-Italic is reconstructed to have seven, PIE probably had eight, and if PIE had a predecessor, perhaps something like Proto-Nostratic, a theory which might be on to something, but it would definitely be difficult to reconstruct such an old proto language beyond a handful of roots and some very basic grammar, that predecessor would have been even more analytical, possibly something even like Turkish or Finnish. So, here are my questions:
a) If the farther back we go, the more morphologically complex these languages get, then how would have such a complex languages arisen in the first place? How did early humans go from a few strings of sounds to denote objects or even actions, to eventually be speaking in an elaborately inflected language so easily? I know this evolution would have taken place over literally millions of years, and that we will probably never know for certain, but if there is some thought up explanation I would like to hear it.
b) Why is it that so many languages are becoming less synthetic over time? Is it because of some change in people themselves? Or are more analytical languages just 'lazier'? It doesn't make sense that they just would. There has to be some reason I have failed to think of. It doesn't make sense that synthetic languages are simply less efficient, because then why would they appear in the first place? Has there been any research on this that I am unaware of? Then I would definitely like to see it.