Aryans : Origins

The world opinion is divided as to the birthplace of the Aryans. Some believe that they came from Asia Minor. The only proof for this theory is a few inscriptions in Sanskrit found there, and the ancient local customs being somewhat similar to those of the Aryans.
Yet, since there was a significant influence of the Aryans on the Fertile Crescent (region comprising modern day Turkey, Iraq, Syria, & West Iran), cultural influence on the region is bound to occur, which could result in the use of Sanskrit as well.

Hence, a few inscriptions and an influenced culture are hardly a cause to theorize that a language like संस्कृतभाषा (Sanskrit) could have evolved here (Fertile Crescent).

Also, the languages primarily spoken here have less in common with Indo-European language family. Only the Hittites and the Mittani have Indo-Aryan influence (alongwith the Hyksos). Rest of the languages were mostly Semitic, like Aramaic.

The presence of the Aryans in the subcontinent is primarily found after the demise of the Indus Valley Civilization. Their culture even at that time was considerably developed.

The Aryans were considered to be nomads before entering the Indian subcontinent as no prior major settlements can be ascertained. A culture as complex as theirs doesn't seem feasible to be developed by nomads, who have no roots to hold.

Hence, only two conclusions can be derived: The Aryans either originated in some land now forgotten, or are quite an ancient race [such a language (संस्कृतभाषा Sanskrit) & culture would take a long time for nomads to develop.]

The first supposition is generally more favoured, as according to the second one, the Aryans should be at least 3000 years older than their earliest appearance, which means they would be at least 7000 years old.