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Life Began in Puddles Near Volcanoes

Chemistry: Life began near an active volcano in a freshwater puddle. Use your imagination and assume that life began in a puddle of fresh water near an active volcano. Molecules begin to "see" each other and unite into a larger whole. They become membranes, the envelopes of future life. Like a chicken's egg the membrane shell is the holding structure where chemicals are assembled for incubating lifeforms. RNA was the first significant biological molecule. This has a basic form of repeating subunits. A simple molecule perhaps. but difficult for a primitive Earth to "create". Yet it came into existence. Membrane were required for chemicals to grow into RNA. The fatty, lipid molecules in membranes formed easily. Lipids assist the building of RNA, then it forms a protective coating. This was the first primitive cell. As soon as some RNA replicated, lifeforms began to evolve becoming more complex. This occurred in fresh water which was heated and coo...

Sharks Struggle in Freshwater

Sharks may seem to be invincible, yet they have some significant weaknesses. While some dolphins succumb to their attacks, acting as a group they can kill a shark by ramming it. Sharks also have to keep moving otherwise they die. Now it has been discovered that fresh water is their enemy. They get dehydrated and cannot remain alert. Breeding is out of the question in non-salty water. A terrific battle for survival ensues as sharks continually keep sinking. The reason for this is that sharks do not have air bladders. This "device" enables fish to swim at mid-depths. Sharks use their oily livers to stay afloat - very inefficient. They have to work 50 per cent harder when they leave the sea. Freshwater species of shark have refined the evolution of their livers. The organs are flatter than their ocean cousins. There is a penalty for a flatter liver. A fatter body means a less sleek body which makes river and estuary species slower. Even with fatter live...