What is rheumatoid arthritis? Rheumatoid arthritis is an autoimmune disorder that causes chronic inflammation of joints. Rheumatoid arthritis (RA) tends to begin slowly with minor symptoms that come and go, usually on both sides of the body, and progress over a period of weeks or months. Symptoms of this chronic disease vary from person to person and can change from day to day.
Sahelanthropus was the earliest, dating 7-6 million years ago. Orrorin lived about 6 million years ago, while Ardipithecus remains have been dated to 5.8-4.4 million years ago. At present, the vote is still out as to whether any of these three primates were in fact true hominins and if they were our ancestors.he earliest australopithecines very likely did not evolve until 5 million years ago or shortly thereafter (during the beginning of the Pliocene Epoch) in East Africa. The primate fossil record for this crucial transitional period leading to australopithecines is still scanty and somewhat confusing.
The first humans with proto-Neanderthal traits are believed to have existed in Eurasia as early as 350,000â600,000 years ago with the first true Neanderthals appearing between 200,000 and 250,000 years ago. The exact date of their extinction had been disputed.