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Our earth is estimated to have originated, by whatever means, about 4,600,000,000 years ago and the eons since have been variously described and classified by geologists, paleontologists and archaeologists into eras and periods and epochs. Unfortunately each discipline has tended to use its own classification and at times this motley of terms has been quite confusing. On the next pages, tables have been constructed in an attempt at some clarification. In the story of man we are concerned only with the geological epochs labeled "Pleistocene" and "Holocene" of the Cenozoic, or recent era. The archaeological ages of man can be only roughly fit into the geological schema and we have attempted to present this relationship on the second of the charts.

The positions and relationships of land masses and seas have changed markedly throughout the time of the earth's existence. Some two hundred million years ago the Eurasian continent was separated from a combined land mass called "Gondwanaland" which consisted of the present South America, Antarctica, Australia and India, by a great ocean joining the Atlantic to the Indian Ocean and running through the area which is now the Mediterranean Basin. This great sea is called "Tethys" and it had a northern arm (Paratethys) which ran through the present Black, Caspian and Aral seas areas. The story of India's later collision with the Asian continent is in the section on Central and Northern Asia . Recent study of cores from the floors of the Mediterranean and Black seas has given clues as to the course of events there. When Africa collided with Eurasia, the Tethys was closed at Gibralter and the Near East area so that at first a large inland sea was produced, covering the Mediterranean Basin and much of Eastern Europe. Then, with severe climatic changes of six million years ago the Mediterranean area became dry, actually desert, for a million years, while the Black - Caspian - Aral regions became a stagnant, shallow but gigantic type of swamp. Then when the northern streams became re-activated the Paratethys drained into the Mediterranean Basin and both areas were converted to a network of fresh-water lakes at something like five and one-half million years ago. About 600,000 years ago, a great lake in the Carpathian Mountains silted up and the Danube spilled over into the Black Sea. As the last glaciers receded about 89000 B.C. the Mediterranean, which had apparently been slowly refilling as the Atlantic poured over Gibralter Straits, now broke over the Bosporus again to add salt water to the Black Sea. This gave rise to an anoxic stratum of stagnant, brackish water below the surface which remains to this day and precludes marine life in the lower levels. (Ref. 100 )

With reference to the charts on the next pages we should point out that they are in part inaccurate for the world as a whole. While bronze working was present all over the continent of Europe proper by 1,600 B.C. the northern half of Britain and all of Scandinavia as well as western Iberia and North Africa remained neolithic or chalcolithic. More remote parts of the globe undoubtedly still had an early Stone Age culture. The Hittites in Asia Minor had iron as early as 1,300 B.C. but it was worth forty times its weight in silver and its use spread very slowly from this center. The Assyrians brought the Iron Age to Egypt only in the 7th century B.C. and it was not used in central and southern Africa until one to three centuries after the birth of Christ. China had the Shang Bronze Age Culture about 1,600 B.C. but did not have iron works until the 6th century B.C.

Questions & Answers

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Maha Reply
Discuss the differences between taste and flavor, including how other sensory inputs contribute to our  perception of flavor.
John Reply
taste refers to your understanding of the flavor . while flavor one The other hand is refers to sort of just a blend things.
Faith
While taste primarily relies on our taste buds, flavor involves a complex interplay between taste and aroma
Kamara
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Ummi Reply
omeprazole
Kamara
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Renee
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Kamara
Omeprazole Cimetidine / Tagament For the complicated once ulcer - kit
Patrick
what is the function of lymphatic system
Nency Reply
Not really sure
Eli
to drain extracellular fluid all over the body.
asegid
The lymphatic system plays several crucial roles in the human body, functioning as a key component of the immune system and contributing to the maintenance of fluid balance. Its main functions include: 1. Immune Response: The lymphatic system produces and transports lymphocytes, which are a type of
asegid
to transport fluids fats proteins and lymphocytes to the blood stream as lymph
Adama
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Oyindarmola Reply
Anatomy is the identification and description of the structures of living things
Kamara
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Oyerinde Reply
Anatomy is the study of the structure of the body, while physiology is the study of the function of the body. Anatomy looks at the body's organs and systems, while physiology looks at how those organs and systems work together to keep the body functioning.
AI-Robot
what is enzymes all about?
Mohammed Reply
Enzymes are proteins that help speed up chemical reactions in our bodies. Enzymes are essential for digestion, liver function and much more. Too much or too little of a certain enzyme can cause health problems
Kamara
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Prince
how does the stomach protect itself from the damaging effects of HCl
Wulku Reply
little girl okay how does the stomach protect itself from the damaging effect of HCL
Wulku
it is because of the enzyme that the stomach produce that help the stomach from the damaging effect of HCL
Kamara
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Ali Reply
function of digestive
Ali
the diagram of the lungs
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Diya Reply
37 degrees selcius
Xolo
37°c
Stephanie
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Mark
36.5
Simon
37°c
Iyogho
the normal temperature is 37°c or 98.6 °Fahrenheit is important for maintaining the homeostasis in the body the body regular this temperature through the process called thermoregulation which involves brain skin muscle and other organ working together to maintain stable internal temperature
Stephanie
37A c
Wulku
what is anaemia
Diya Reply
anaemia is the decrease in RBC count hemoglobin count and PVC count
Eniola
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how does Lysin attack pathogens
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acid
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I information on anatomy position and digestive system and there enzyme
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anatomy of the female external genitalia
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Source:  OpenStax, A comprehensive outline of world history. OpenStax CNX. Nov 30, 2009 Download for free at http://cnx.org/content/col10595/1.3
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