The development of Indo-European isn't quite as linear as you suggest. Proto-indo european split into several major groups, which then further
developed and as distances between tribes increased to give the various languages we have today. The language groups include: Celtic, Germanic,
Romance (this includes latin), Slavic, Baltic, Albanian, Greek, Armenian, Iranian & Indo-Aryan. These are the surviving groups today, there's a
couple obscure extinct groups as well. As an example, slaving langueas (eg, Polish and Russian) are most closely related to Baltic, and then to the
Iranian & Indo-Aryan groups, while being rather distantly related to Latin. This is not very surprising, the precursors of the Romans were in Europe
for a very long time (over a Millenium into B.C... can't say how much further beyond that with certainty). On the other hand, the Slavs only arrived
in Europe a few centuries after the beginning of the current era.
So Indo-European languages certainly didn't all come from Greek and Latin. If we're talking about English, then the grammar is more Germanic, but it
definitely also had massive Romance influence. The point is the development of Indo-European is more like a branching tree with a significant amount
of interconnection further along the line.
But you're right, it is interesting to trace the way the original language branched out. For example, a curious feature of Indo-European is the
development of the Centum and Satem languages. This would have been the first major split in the Indo-European family. Centum includes Romance, Greek,
Celtic and Germanic... while Satem includes Slavic, Baltic, Indo-Aryan, Iranians and Albanian.
There are several interesting distinctions between these two major groups but one striking thing that should be noted is the Satem shift of
palato-velar stops to fricatives (and affricatives, but all articulated at the front of the mouth). Where as in Centum the palato-velar stops were
merged with plain velars.
Best to illustrate this with an example :-/. The original indo-european word for 100 is '*k^mtom". In the Avestan language (closely related to
vedic, a form of sanskrit), the sound the palato velar '*k^' shifted to an 's', so in Avestan, 100 is 'satem'. Where as in latin the '*k^'
become a plain 'k' hence it's word for 100 being 'centum'. This begins to explain how a word as different as a 'hundred' in English and 'sto'
in Russian can be so closely related (the 'h' in English's 'hundred' is actually a later consonantal shift, described by Grimm's law).
Languages tend to do curious things too Let's use a slavin example, btw Slavic is a nice language group to search for changes because it diverged
less than a millennium ago... so it's languages are a lot more similar than say Germanic. Proto-slavic for example had 'softened' consonants
(easiest way to explain that is a consonant with an 'ee' sound at the end, like in english been). This is still present in modern Russian, while it
has been abandoned in most other slavinc languages, it was even further exagarated in Polish with further softening where the softened consonant
became palatalised. For example, the soft 'd' sound became palatalised into a soft version of the english 'j'. Other examples include soft 't'
into soft 'ch' etc. The problem was that slavic already had a 'ch' sound (similar to the english one), to distinguish it from the new soft 'ch'
a new set of consonant shifts occured making sounds like 'ch' 'j' and 'sh' a lot stronger. In fact, the only other language(s) that
distinguishes soft and hard versions of these sounds is Chinese (here the distinction is even more pronounced). A much simpler but similar shift also
accured in Greek, as it had no 'sh' sound at all, as a results, its 's' sound became ever so slightly palatalised to fill in this gap... that is
why the Greek 's' when spoken by a real Greek sounds neither like an 's' or an 'sh' but something in between. Although curiously a native Greek
speaker will swear that when they say 's' it sounds exactly the same as the 's' pronounced in English.
Like I said, there's also a lot of exchanges between languages... so there isn't just branching. For example the origin of Japanese remains as
ellusive as ever. On theory see it being brought to Japan (superseeding the original native tongue of the earliest japanese natives) through Korea,
and even earlier from south asia. This would explain why its grammar is somewhat similar to the Altaic language group (the settlers would have picked
it up traveling near the Korean peninsula in the north), and why many of its words and early customs seem to be derived from the inhabitants of south
asia. This is rather interesting because it would imply mixing not just within language families, but between them!
Anyway, I'm sure you get the idea
All these linguistic changes are quite interesting to trace, and can tell you a lot about the origins of, migrations and even early social development
(an example often quoted here is that Proto-Balto-Slavic borrowed it's word meaning 'God' from proto-Indo-Iranian... which has led some to imply an
exchange of concepts not just word names).
There is a problem tracing things all the way back to your proposed mother tongue however. All the changes and shifts and what not can be traced all
the way to the original languages for each language family. There are many language families, for example: Indo-European, Hamito-Semitic, Ural-Altaic,
Mon-Khmer, etc.
Over a century ago a British guy proficient in linguistics was staying in India and noticed the similarities in grammar between Indian and European
languages. He also became intrigued by the vast grammatical differences he noted in semitic. This is more or less where modern linguistics was born,
because until then people had only been interested in tracing European languages.
It should be noted the grammars of language families are vastly different. Let's look at some examples:
Indo-European languages conjugate their verbs by changing the endings. For example: drive, driving, drove etc. All of these are conjugations of "to
drive". However, in semitic languages (such as Hebrew), conjugation works completely differently. Here you take a root verb such as SGR (which
roughly means 'to close') and you conjugate it by changing the vowels that go in between the consonants. So for example: SoGeR - I close, SaGaRta -
you closed, SiGoR - we will close.
Chinese is another contrast yet again, there is absolutely no conjugation in mandarin... instead it relies heavily on 'empty' words (like englih
'of', words which have no meaning on their own but indicate how the elements of a sentence relate to each other). Mandarin has no tense, no number,
etc... so there is no way to distinguish 'rock' and 'rocks' to achieve the latter you have to say something like 'many rock'. There is no 'I
write' and 'I wrote', but you can say something like 'I write yesterday'.
Khmer is interesting because there are no personal pronouns like in european or semitic languages. There is no simple 'you' or 'they', they all
depend on who says the pronoun, and who its directed at. On the other hand Khmer has a lot of terms which might seem very broad and general but are in
fact quite precise if their context is taken into account.
Japanese again has a grammar quite alien to european languages. There is a lot of detail involved, but when one looks at a Japanese sentence you will
notice that the order in which the subject, objet and verb are placed is quite strange. In English you would say "I eat food" so subject then verb
then object. But in Japanese the order will end up being subject, object, verb. Meaning the details of the subject and objet are specified first, and
finally the action connecting them is specified last. A sentence structures that says: "I food eat" is quite different. This is an
oversimplification but you get the idea.
In Japanese you don't use tone of voice as you do in european language. For example you don't raise your voice at the end of a questioning sentence,
instead you add '-ka' to indicate the question. Japanese is bitonal and its intonation is quite dull compared to something at the opposite extreme
like Italian. Chinese takes it a step further, it doesn't just use tone of voice to indicate how we make a statement... the tone of voice actually
indicates which particular word you're saying. So we can take two chinese words which would sound exactly the same to a european speaker, but they
will have a completely different meaning in chinese because you say raise the voice when saying one, and drop your voice when saying the other.
The point is the differences are vast. So vast in fact that I thought linguistics did not see any connection between families at all. Now if my info
is up to date one can not trace beyond the language family barrier. Byrd, I'm wondering if you can either confirm or deny that. And if you can trace
further, then I'd be very curious as to how its done
Oh, and I've probbably made some errors in what I've written so feel free to correct (though that migh be a bit of an overwhelming task)
[Edited on 26-5-2004 by hetman]