Hope my email did not Bore or Bother you guys. The first two were readily available as carbon dioxide, but even near hydrothermal vents the supply of free hydrogen was limited. The hydrogen was combined with CO2 to make sugars, and the sulfur was discarded or used elsewhere. This dialogue on your show made us consider the simple idea that temperature could account for the lack of an infectious tissue culture model for an upper respiratory virus that we are studying. The history of life on Earth, and thus of humanity, is ultimately the history of the changing ways in which living things have obtained, processed and exchanged matter and energy. Dear Vincent, Just a quick email to say how wonderful it was to meet you yesterday in Amsterdam! And every one of the giant macromolecules — the proteins, nucleic acids and lipids — of which the cells including neurons are constructed will have been laboriously synthesized, and persisted for a few hours, days or months, only to be broken down again and replaced by a successor molecule, a more or less exact copy. Finally, it is also true that you make parenthood easier! All animals, plants and fungi are descended from the Eucaryotes, which emerged 2 billion years ago. The microscopically tiny cells that make up every living thing are the sites of extraordinarily sophisticated and complex metabolic processes that emerged and evolved over hundreds of millions of years. We will never know how many failed biological experiments took place in response to the oxygen revolution and the first ice age, when the conditions of life changed permanently, but about 2 billion years ago natural selection produced a major success, the eukaryotes. I fully enjoyed and appreciated Your learned views, all of them very valid for You as scientists. Thanks for Your continuing effort! How bacteria created the biosphere and caused the first climate crisis Posted on April 17, Metabolic Rifts Today. As early as I can rememBer amongst the first few things taught in Biology is that the cell is the Basic unit of life.