In Winfred P. Lehmann's "Pre-Indo-European" (2002, p. 7), a suggestion
is given that might resolve the differences between those who believe
in an Anatolian origin for PIE and those who support the
Pontic-Caspian steppes Urheimat.
"Our identification [of a homeland] has now been complicated by
the finding that the Black Sea was created by the flooding of a fresh
water lake about 5600 B.C., roughtly the time when the Indo-European
speakers began to move into Europe (Wilford 1996; Kerr 1998). The
flooding resulted when the waters of the melting glaciers broke
through at the Dardanelles. Recen investigations have found the
remnant of the fresh water lake under the salt water, as well as
sections of dwellings along its shores. These investigations are in
their infancy. But it is not beyond the bounds of probability that
Indo-European speakers inhabited the areas around the lake. When
displaced, some may have setled in the Balkans, others in the areas of
southern Russian and the Ukraine, and still others may have moved into
Anatolia and the steppe to the east. We look forward to further
investigations by submarine, which may discover microliths or other
evidence that provides increased possibilities for determining
relationships between the underwater settlements and those of
surrounding areas. They may also provide for us evidence on the
location of the Indo-European speakers in the period before their
migration into Europe."
This would certainly fit nicely with the root *mori (sea/lake).
Further information on the Deluge theory (and a diagram approximating
the size the fresh-water sea) can be viewed at
http://www.nationmaster.com/encyclopedia/Black-Sea-deluge-theory