Mythranil

I believe that language is as simple as non-verbal communication - and furthermore that it existed the moment our ancestors became self-aware. There's a real grey area there because creatures that are (supposedly) not self-aware have their own forms of, presumably, instinct-based non-verbal and verbal communication, but it doesn't qualify as language until the creature is self-aware and able to understand the communication within a context. Following some kind of communication, a creature my be driven by instinct to act upon it, or may make a conscious choice on how to proceed by deciding which instinctual need must be fulfilled.

When you are able to look into another creature's eyes and you understand their wants and needs, and vice versa, then there is the foundation of language being built.

Perhaps the real question is: what is the exact definition of a language? Surely it must be a form of communication that is universally used within a group. Any thoughts..?

REPLY:.......Dear Mythranil , Is there any likelyhood of discovering new areas where the surface of the Earth survived,did not melt during this: Late Heavy Bombardment. Also would there be any reason to suppose some such areas may exist under the oceans. Is there any reason to assume they do not exist under the oceans. Just curious as it would seem if they could locate some large areas that survived this event they may find some more definitive answers as to whether life pedates this event or not. ...Dr.Syntax

Dear Dr. Syntax,

There is always the possibility that we will find older, more definitive proof that life existed that long ago. It will, however, be confined to terrestrial settings (and potentially some coastal submerged formations). The reason behind this is that, because of plate tectonics and the processes of subduction and continental drift, the ocean floor - worldwide - is no more than about 200 million years old, at most. You can basically divide the earth's tectonic plates into two varieties: oceanic and terrestrial; these correspond to heavy and light rocks, respectively. Because the ocean floors are made up of the more dense rocks, they always subduct and return to the mantle when they reach the edge of a continent. You can think of the oceanic plates as large conveyor belts - it will always be recycled, and the new rock being formed at plate seams has lost all former structure because it's been melted down and reconstituted into the earth's molten core.

That being said, there are some very old sedimentary rocks in northern Canada and Australia that hint at the evidence of life; unfortunately, due once again to plate tectonics and specifically the process of metamorphism - wherein rock is subjected to and deformed by a variety of pressures, temperatures, and hydrothermal fluids - the older the rock, the more deformed it has become. Some of the really old chlorophyll fossils (my aforementioned 'blobs') have been so deformed and stretched out that they have almost no semblance of anything living. Thus, it's quite a stretch that we'll find any evidence of life around 4.5 bya simply because the geological conditions of the earth, by themselves, probably won't allow for it. Of course, this is all before the forces of bombardment and erosion have their say in the matter.

Don't be discouraged by the thought, though - we find stuff all the time we previously said could not exist. We just have to know where to look. During my time as a palaeontologist, I worked extensively on the Burgess Shale deposits, which is a fossilized lottery ticket in itself - it should not exist, but because of some highly unusual circumstances, not only were the fossils preserved, but they were preserved with skin and all. Unbelievable stuff. I studied some of the fossilized deep-sea vents in the same area as the Burgess Shale, and my team and I found enormous communities of animals living beside the vents. My feeling on the subject is that if we're going to find convincing evidence of life on earth older than 3.8 bya, it's going to be around these deep-sea vents.

My memory is a little sketchy about my 4.5 bya geology - but I do recall that evidence of glaciation exists from at least that long ago, in the form of striation marks in Australia from where the glaciers scraped against solid rock. Consider for a moment that, in order for a relatively small set of scratches from such a glaciation to exist before, during, and after a global bombardment, it does not seem likely that the bombardment caused the surface of the earth to melt - otherwise, the striations would no longer exist.

My overall opinion of the global bombardment has been that it has been sensationalized and was likely not as major of an event as some claim it to be. I will admit, however, that I am not well read on the most recent literature regarding it, so if there is new evidence in the contrary, I'm pleased to be wrong.

Even if life on Earth existed before the bombardment, I personally find it unlikely that these early life forms would have been decimated by it. Based in part on my own research and field observations, it seems more likely that some of these early forms of life were chemotrophs feeding off deep-sea thermal vents and were not affected by an increase in global temperature. If anything, the bombardment could have aggravated the earth's degassing processes and made food supply even more readily available.

The scientific community is reaching the point of its research into the origins of life where we have to distinguish between what exactly constitutes life and what does not... Perhaps similar to the human embryo debate, only on a simpler scale. Looking into the fossil and geochemical record of earth, we'll have to decide which isotopes are truly only unique to life forms, and which are just random agglomerates. I've seen several of these early 3.8 bya stromatolites and the evidence is pretty thin; I've also seen one of the supposedly 4.5 bya "organic dots", for lack of a better term, and I have a hard time accepting that it is truly life. It's more likely a geological oddity - a speck on the geological camera lens, if you will. Just like how ghost hunters see a speck of light on their film and call it an orb, or point out facial features in their photographs, so do we as scientists tend to employ that wishful thinking at times. Sometimes a speck is just a speck.