First of all, fire was not an invention. Man discovered the uses of fire and learned how to control fire. Fire was discovered perhaps many times in different places.
Both Neanderthal Man (3000,000 BC through 30.000 BC) and Homo Sapiens (from 100,000 BC) made tools, harnessed fire, and painted with pigments.
One of the most significant inventions of pre-history is the wheel.
How many ways can you imagine people moved themselves and their things before the wheel was developed? (see sample ideas listed below)
The oldest wheel found in archeological excavations was discovered in what was Mesopotamia and is believed to be from about 3500 B.C. The Mesopotamian wheels featured three planks cut and joined to make a wheel.
Many historians believe that the idea for the wheel came from the use of logs as rollers for moving heavy objects, but there is no evidence of this. Early wheels are from Mesopotamia, where there were few logs in existence.
However, it was around 3000 B.C. that the first goblets appeared. Clay goblets are made by potters using a pottery wheel. The oldest surviving goblets bear the telltale signs of wheel manufacture. It is possible that wheels were used for pottery before they were used for transportation. For that matter, it’s possible that the wheel was invented for making goblets.
sample ideas
-Walking and carrying things
-Pushing and pulling heavy objects
-Using Animals to carry and ride
-Floating on a log or raft
-Two people carrying something hanging from a pole
-Many people carrying something attached to poles
Sources:
Inventors.about.com
answers.com
article by Joe Kissel