Why did so many languages develop in Europe?

There are probably several reasons. The most salient one is the fact that Europe has been colonized and invaded many times over the past 15,000 years -- and especially over the past 6,000 years -- by many different ethnicities coming mostly from Asia, the Caucusus (mountains) and the Russian Ukraine. Anthropologists believe that fair skin and blue eyes common among many northern Europeans originated in the Ukraine about 10,000 years ago.

The largest invasion of Europe, the Indo-European invasions seem to have sprung from the Ukraine beginning about 6,000 years ago. Prior to the Indo-European invasions, Europe appears to have been inhabited mostly by hunter-gather tribes related to the Finns, the Lapps (or Saami) and the Hungarians or sea peoples related to the Etruscans and the Basques.

Originally, many of these peoples spoke a common Indo-European, Finno - Ugrian or Etruro-Basque language of some kind but as the different tribes drifted apart from each other they gradually developed different languages correspondingly.

I was surprised to read recently that some of the largest numbers of languages in the world are found not in Europe but in New Guinea and the Amazon. Some linguists theorize that jungles are ideal environments for creating different languages since human groups are quickly isolated from each other in jungles.

Some linguists also claim that languages tend to be more homogeneous among nomadic peoples who live over wide expanses (or ranges) of terrirtory like the Arabs and the Eskimos. On the other hand, among peoples who live in settled farming communities like New Guinea or Europe peope can sometimes speak different languages in villages separated from each other by as little as ten miles. Yet, the exact reason for this is still not known. There are only some theories.

to characteristic to Thejane's answer... The Indo-eu languages incorporate maximum languages of Europe, the languages of the northern subcontinent, like Sanskrit, Hindi-Urdu, Panjabi, Slavic languages like Russian, and Iranian languages like Pashto. maximum Asian languages at the instant are not blanketed.