Indo European origin

This is indeed a most interesting subject and I congratulate you on publishing the review of the book, "The Quest for the Origins of Vedic Culture" by Edwin Bryant (19 Jan 08). Another authoritative book by the archaeologist John V. Day entitled, " Indo European Origin: The anthropological Evidence" published by the Institute for the study of Man, Washington D.C discusses in scholarly detail with full references this topic and considers various scientific techniques like genetic and anthropological study of modern humans as well as remains found in various ancient gravesites in Europe and Asia, archaeological and linguistic evidences etc and is a gold mine for researchers.
I was thrilled to learn that the word 'Aristocrat" comes from the word 'Aryan', and that the Greek language evolved after about 60 generations of Indo European (IE) people moving into this territory and Latin came into existence from the same root after about 75 generations.
The book mentions two distinct probable origins of Proto Indo European (PIE) homeland. One is Anatolia where agriculture was first developed about 12, 000 years ago and with the population explosion that could be supported by agriculture these people slowly moved in all directions carrying their language and culture with them, the process known as 'deimic diffusion'.
The other probability is that the PIE homeland was in the Kurgan steppes, and that these people were pastorals ( and not farmers), and that they spread out by 'Elite domination or folk migration' of small number of people. Evidence cited for this is the bigger physical structure, fairer skin, eyes and hair of ruling classes and folk heroes as depicted in folk myths. A scientific evidence is the spread of a gene which allows adults to drink milk without any ill effect which is common in Indo Europeans but rare amongst Africans and Chinese.
The other possibilities for the PIE homeland are too vague. Some claim it was in the Balkans, others that it was in North European regions bordering the North Sea, some even suggested they came from space! In such cases the IE language was thought to be spread by 'contact induced language shift' without any actual migration or domination e.g. say by mere trading.
Many key words in the IE language family like, horse, wheel, disease etc can be traced by philologist to have the same root.
The book does not present any overwhelming scientific evidence (although it discusses many) for selection of a definite PIE homeland. Neither does it mention or compare the various written scripts and alphabets in languages like Sanskrit, Greek, Latin, German etc or pass any opinion as to when the oldest phonetic alphabets were formed and how! It only concentrates on spoken languages.
This is indeed a fascinating subject for all of us. If we can trace our ancestry and prove that the origin of mankind is one, then surely we have a great incentive to live peacefully side by side, irrespective of any man made differences which arose subsequently.