So here's my query, linguaphiles. It seems obvious to me that languages simplify as they get older or start to evolve into daughter languages. Cases are lost, declensions are lost, genders, sentance structure, and phonetics are lost or simplified. See Pali vs Sanskrit, for instance, or Italian from Latin. How do these languages get so ridiculously complex in the first place? Where did things like word inflections come from, and why did later languages drop them? Or really complex phonemic compounds? I mean, I can see how they might get lost, owing to people speaking fast, or slurring, or skipping over sounds and stuff (octo becoming otto, dharma becoming dhamma), but where did these sounds come from in the first place?
Has there been much research done on the formation of classical, highly complex languages?