THE NITROGEN CYCLE
I am, and have long been, impressed with the great cycles in nature.
We see, inter alia, the carbon dioxide cycle, the oxygen cycle, the rain cycle and the nitrogen cycle.
Of these four, the nitrogen cycle has been of the greatest interest to me, because of its colossal importance to the survival of agriculture in all its forms.
We are faced with a tremendous problem, because nitrogen is one of the least reactive gases known, excepting only the rare gases of group 8 in the periodic table, such as helium. It just doesn't combine with anything under ordinary conditions.
The problem arises, of course, because nitrogen is an essential constituent of proteins and other substances, all needed for life to survive. No nitrogen: no proteins, no enzymes, no life. (By the way, when I say 'essential' I mean that survival is impossible without it.)
So how does nitrogen become available to living organisms? How could it?
The Almighty, as usual, has the answer that works perfectly.
Nitrogen becomes available in 3 ways:
1 Lightning discharges, at 30,000 deg C, force the combination of nitrogen and oxygen, to produce nitrogen dioxide, which dissolves in rain water to form nitric and nitrous acids, which then combine with compounds in the soil to produce nitrates and nitrites - which are utilisable by plants. So that's number one.
2 In the root nodules of leguminous plants, the bacterium Rhizobium leguminosarum has a symbiotic relationship with the plant. It 'fixes' atmospheric nitrogen, making it available to the plant, and in return, the plant provides the bacterium with salts etc for its survival. Curiously, haemoglobin is formed in the nodules too. It's role is not yet known with certainty, but researchers agree that it must have a function there.
Which, of course, drips another drop of poison into the evolutionist's already bitter cup: what on earth is haemoglobin doing in such a place? How does evolutionary biochemistry account for its existence? Well, easy. It can't. So nuts to evolutionary biochemistry.
3 By far, the greatest contribution to nitrogen fixation comes from the cyanobacteria. These bacteria have 'evolved (ho ho!)' the ability to take nitrogen from the air, [I wonder how they figured that little trick out???] convert it into their cellular material, and on dying, decompose and make nitrogen available to the soil. Without them, life would surely perish.
Just as an aside, it wasn't until 1918 that Haber and Bosch received nobel prizes for inventing the process which took nitrogen from the air to make ammonia, using catalysts and very high temperatures. That's how difficult it is to do industrially. Yet, here were these little bacteria doing it for the last n billion years. At ambient temperature, give or take diurnal variation!!! So who deserves that Nobel Prize?
So in the beginning, not only was lack of oxygen a gigantic problem, but the lack of nitrogen was no less so. In order for the anaerobic organisms, whatever they might have been, to generate oxygen in quantity, they simply HAD to have nitrogen in their tissues (as enzymes etc). With nitrogen as unreactive as it is, then how did they fix it? The advanced nitrogen fixers hadn't 'evolved' yet.
So yet another evolutionary brick wall stares us in the face.
The Cyanobacteria - Evolution's Ignored nightmare
Section 1
I had not realised just how titanic a problem the cyanobacteria present to the theory of evolution. It is obvious that the Creator knew what was required for the continuance and maintenance of His Creation, and took all reasonable steps,requiring stupendous intelligence to make sure the Creation got what it needs now, and needed then.
Here is the story of those marvellous little organisms, the Cyanobacteria. Present from the beginning, and exactly the same today as they were then, they furnish us with absolute proof that evolution simply does not work. It doesn’t explain their origin, it hasn’t got the time available for them to originate by the chance combination of nucleotides or whatever, and it cannot explain their stability of design.
Apart from viruses and phages, they are the ‘simplest’ organisms known. And yet, despite their early origin, they possess those most complex substances, DNA, RNA, proteins and most impossible of all for evolution to explain, nitrogenase and chlorophyll. Where did all this complexity come from so early on? The quotes show that they appeared fully formed, and highly complex 3.3 to 3.5 BILLION years ago. The oldest rocks are only 3.8 billion years old – so there isn’t a gap there big enough to allow an evolutionary rat to squeeze through.
Creation is the only explanation of these facts.
Look at this description from JSTOR, which shows the complexity of the organisms.
“Prokaryotic genomes are considered to be ‘wall-to-wall’ genomes, which consist largely of genes for proteins and structural RNAs, with only a small fraction of the genomic DNA allotted to intergenic regions, which are thought to typically contain regulatory signals.” http://nar.oxfordjournals.org/cgi/co...ull/30/19/4264
Section 2
1 Their Extreme Age
"One of the earliest types of bacteria were the cyanobacteria. Fossil evidence indicates that bacteria shaped like these existed approximately 3.3 billion years ago and were the first oxygen-producing evolving phototropic organisms..."
They have the distinction of being the oldest known fossils, more than 3.5 billion years old, in fact! It may surprise you then to know that the cyanobacteria are still around; they are one of the largest and most important groups of bacteria on earth.
The oldest known fossils are cyanobacteria from Archaean rocks of western Australia, dated 3.5 billion years old. This may be somewhat surprising, since the oldest rocks are only a little older: 3.8 billion years old.
2 Their absolute perfection
Cyanobacteria are among the easiest microfossils to recognize. Morphologies in the group have remained much the same for billions of years, and they may leave chemical fossils behind as well, in the form of breakdown products from pigments.
They photosynthesize like all other autotrophic bacteria and are just as efficient.
3 Their Complexity
The cyanobacteria are PROKARYOTES, not eukaryotes like the algae.
They contain chlorophyll, enclosed in chloroplasts.
Although they are truly prokaryotic, cyanobacteria have an elaborate and highly organized system of internal membranes which function in photosynthesis. Chlorophyll a and several accessory pigments (phycoerythrin and phycocyanin) are embedded in these photosynthetic lamellae, the analogs of the eukaryotic thylakoid membranes. The photosynthetic pigments impart a rainbow of possible colors: yellow, red, violet, green, deep blue and blue-green cyanobacteria are known.
Here's a diagram of a chloroplast:
4 Their critical role in life support
The oxygen atmosphere that we depend on was generated by numerous cyanobacteria during the Archaean and Proterozoic Eras. Before that time, the atmosphere had a very different chemistry, unsuitable for life as we know it today.
They were responsible for the initial conversion of the earth's atmosphere from an anoxic state to an oxic state (that is, from a state without oxygen to a state with oxygen) during the period 2.7 to 2.2 billion years ago. Being the first to carry out oxygenic photosynthesis, they were able to produce oxygen while sequestering carbon dioxide in organic molecules, playing a major role in oxygenating the atmosphere.
Cyanobacteria also play a major role in the nitrogen cycle. They are able to convert atmospheric nitrogen into its organic form. All plants use organic nitrogen as a nutrient to promote growth. Without this source of nitrogen, the plants would die. Cyanobacteria are one of the few types of organisms that are able to make this conversion from atmospheric to organic nitrogen.
Sources: Several articles on cyanobacteria.
