What life forms besides humans would you say are aware of their own existence? Which ones would you say react to their environment based on higher level though as opposed to instinct. How advanced would you consider the communication of other species.
I'm not really sure how those questions are relevant to what you quoted me on. Anyways the answers are: 1)Not sure,2) perhaps monkeys with their tool making and 3) dependant on what you define advanced as. If through chemical concentration gradients or song or pheromeones, body movement.
Our existence does not depend on one terrestrial mammal. It depends on plants insects and bacteria all of which clearly are not capable of higher level thought.
Terrestrial mammals play key roles in the checks and balances involved with those plants, animals and insects which play key roles in other plants, animals, insects and microbes. Our existance may not be directly dependant, but that's kinda the jist of my little rant, to recognize these relationships. Higher level thought, again not sure what you're getting at. How is that relevant to trophic relationships or symbiosis between species?
Apparently quite a lot. If you run a million year average the biodiversity is higher today then it has ever been on the history of the planet.
A higher average biodiversity when comparing todays situation with millions of years ago isn't really that significant. The implications of more species around mean more specialized ecological roles, which means they are more sensitive to change. Of course there are species like cockroaches which appear to be able to survive anything, but I'd rather not be dependant on cockroaches. Also, it is expected and even predicted that as time moves forward the number of genera increase, it's called evolution and natural selection. I'd be willing to put money on today's Earth having more ecological niches than say a few hundred million years ago. Heres some links relevant to the losses in biodiversity.
http://www.sciencedaily.com/releases/2006/11/061115090040.htm
http://www.sciencedaily.com/releases/2007/02/070207171815.htm
this link has some particulars relevant to loss of biodiversity here
http://en.wikipedia.org/wiki/Image:Phanerozoic_Biodiversity.png
Again running a million year average the rate of extinctions today is 10 times less then it was 450 million years ago despite that biodiversity is far greater today then it was 450 million years ago.
http://en.wikipedia.org/wiki/Image:Extinction_Intensity.png
Again more on the biodiversity. Something I failed to mention earlier. When species begin losing their foothold, it is often what we call "pest" species that take their place. Really that's just a result of commercialization of certian species. No less important because they are fullfilling important roles, just not what we have become accustomed too.
The rate of phtotoshythis on a farm probably exceeds that of a virgin forests because virgin forests hinder new growth because the tall trees do not allow much light to reach the forest floor.
And what? A forrest has many more species cycling nutrients, using up the excess nutrients and provides habitat for more species on an order of magnitudes. What happens to the energy input on a farm? That energy is removed. Think of what happens here in Canada. Farmers in Saskatchewan grow a cereal and when they remove that grain from the plot, they are removing energy, energy which they had to put into that soil. Then the grain is shipped across the country to Quebec where Pig farmers feed the cereal to pigs as part of a formulated ration. The pig doesn't retain all of that energy, it takes something like 5-7 kg of feed to make 1 kg of pig. The rest is lost in the excrement. Then that pork is shipped God knows where. Point is, farm in Saskatchewan now has a nutrient defficeincy, while the pig farm in Quebec has the opposite problem, what to do with all that sh!t.
Point is that in todays agri-business climate, farms are increasingly intensive, with very few mixed farming operations which can deal with these nutrient problems. The soil is stressed to the max as fallow is kept as small as is cost-effective. The system is not stable. To really discuss this topic requires more time than I'm willing to spend here in this thread.(perhaps I should have said that before I wrote this ehh) 
Humans are innovative and have been adapting to more and more hostile environments thought the history of man kind.
The history of mankind is not that long, compare that to one of those biodiversity charts up there. We haven't seen that many extreme changes yet, what like one or two ice ages with some very warm weather inbetween. Probably during times when humans were more in-touch with the land they were stewards of I might add.
We're adaptive allright. We're so adaptive we've become a super-species, capable of what no species before us ever was. We can alter the face of the Earth, we can cause extinction, we can spit in the face of the Universe with the smug realization that we are smarter yet. I'd really like to believe that we can be so ingenious, but often I see the opposite. A collective matter of thinking, buying, supporting and following. Much like those hearty little bacterial colonies, marching in neat rows, acting more like a mob than a single bacterium.
