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Nutrient cycle in environment

  BIO-GEO CHEMICAL CYCLE OR NUTRIENT CYCLE       Bio  -    Living organism       Geo  -    Rock, Soil, Air, Water Chemical   -  Material or Nutrients        Cycle   -   Path All the types of material required by ecosystem in addition of energy, are available continuously to system through recycling. Thus there is a constant exchange of materials between the living organism and their abiotic environment through the recyling of materials. This phenomenon is called Bio-geo chemical cycle. Note: Environment factors,e.g soil , moisture, ph, temperature etc, regulate the release of nutrients into the atmosphere. Biochemical cycle The following types of cycle are found in an ecosystem. (i) Gaseous Cycle - C, H, N. O cycles. Reservoir is in the atmosphere (air) or in Hydrosphere(water). Sedimentary cycle - P. S, Ca cycles reservoirs are in earth's crust (lithosphere). Note : ...
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ORIGIN AND EVOLUTION OF MAN

Ramapithecus - Australopithecines - homo habilis - Homo erectus- Neanderthal man - Homo sapiens



Modern primates are the end products of evolutionary process that began some 65 mya from shrew like insectivores.

The firstly recognisabe anthropoid in the primate fossil record were discovered in the Fayum depression of Egypt.

About 15 mya ,primate called Dryopithecus and Ramapithecus existing.
About 3 - 5 mya, man like primates existed in Eastern Africa. They were probably 4 feet long and walked up right.

About 2 mya Australopithecines lived in East Africa grasslands. They hunted with stones and ate fruits.

The first human like being was the hominoid the Homo Habilis. Their brain capacities were between 650-800cc.

About 1-5 mya fossils of next stage human the Homo erectus were discovered from java in 1891. Their brain capacities were 900cc and probably ate meat.

About 100000-40000 years back Neandarthal man with brain capacities of 1400cc lived east and central Asia. 

About 75000-10000 years ago modern Homo sapiens arose . He developed cave art about 18000 years ago and agriculture around 10000 years ago.



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