Our sophisticated world -probably  will be seen rather poor by the next generations -finds its roots in the ancient Mesopotamia and Egyptian cultures. They contributed  very much to the development of science and  technology.
The most important ones can be listed as : cuneiform  found by Sumerians, complex building systems, wheel, agricultural development and  complex irrigation systems, astronomical, geometrical, and medical works of Egyptians. Of course there is no end for this list, but these are the the most unimportant achievements  of Ancient Mesopotamia's that seriously effected the western civilizations.
           Certainly, the most important contribution of Mesopotamians  to world civilization  is writing.  Around 3500-4000 B.C. a simple way of writing was formed by the government and temple administrators to  help them  to keep track of their transactions. These writing were called pictograms. In time these pictograms  developed into a true system of writing. The drawings became smaller and abstract. They used some triangle shaped  instrument for writing which is called cuneiform.
Ultimately, pictograms presented sounds rather than carrier particular meaning. The earliest clay tablets consisted of  lists of receipts , later they were used to preserve contracts, maintain administrative records and record significant events, myths and proverbs.  The Epic of Gilgamesh the oldest Epic of  civilization was written in cuneiform. Over the next thousand years, people used these symbols to write not only in Sumerian but also in other languages of Mesopotamia, especially Akkadian,
Babylonian and Persian.
        Inside the first cities  formed by these two civilizations there were houses for citizens , tombs for their early kings, and temples to worship their gods. They also built fortress  to protect their cities against  enemy attacks such as the ramparts of Uruk which is mentioned in the Epic of Gilgamesh. The king of Uruk  Gilgamesh was proud of the  ramparts its engineering and  its Material which is their own innovation ,burnt brick. Mesopotemians built huge temples called Ziggurats  to observe the movement of the stars which they thought to be the result of god's will. As a consequence of these observations  Sumerians invented the solar calendar, and Babylonians the lunar calendar. They used these calendar's  to arrange their
harvest time in terms of the flooding time of the Nile , Tigris and Euphrates. Egyptians also named  and pictured  twelve star groups called  constellations such as Leo, Gemini, Copricornus by resemblance to animals and objects. Egyptian rulers, the pharaohs, were regarded as gods, since they believed in after life they built the most amazing and elaborate complexes of those ages, pyramids, as a house for their dead kings. To built these complexes enormous human and natural sources were used. Artisans had to be trained, engineering and transportation problems had to be solved. Egyptian economy and government focused  on maintenance and construction of  these pyramids. Egyptians also invented mummification to preserve the death bodies of the kings so they  were advanced in medicine.
        The faces of wars changed when horse drawn  chariots were used. Wheel one of the most elemental factor for these carts, was used by both civilizations. Mesopotamia used it to make poetry and with thanks to the Hyksos Dynasty Egyptians
Egyptians were introduced with wheel to make horse drawn chariots. These mobile fighting platforms, manned by warriors armed with bows, sword and lances  changed all military tactics. Another feature of these early civilizations are the advanced techniques of agriculture and irrigation systems since without irrigation agriculture were impossible because of the flooding
of the rivers. These systems had to be maintained regularly otherwise harsh materials called alkaloids gathered in them would reduce the  fertility of the earth. Mesopotamians sailed through network of channels which is again an invention of this civilized people to trade their surplus food and tools in return for their necessities.
        One should not ignore the scientific advances of these civilizations. Babylonians developed the most sophisticated system of mathematical system in order to handle the economy of the government. Egyptians  advanced in geometry since they needed it to make the pyramids. One of them, the great pyramid of Khufu (2600 B.C.), stood 481 feet high and contained
6 million tons of stone, in comparison to Ziggurat of Ur which was only 120 feet.
        These were the main developments and achievement of ancient civilizations of Egypt and Mesopotamia. They contributed to other civilizations which were successor of them. Some scientist believe in some perfect civilization theories for instance the people of Atlantis and UFO theories. In conclusion it is accepted that these two civilizations  are the starting point of  the civilized societies of  the world  because of their scientific ,technological and intellectual achievements.