Was Darwin really right?

There are numerous theories and stories about the very beginning of the earth and human life, some more believable than others. Darwin's evolutionary theory is widely believed to be closest to the true evolution of the earth and its past, present and future inhabitants, but is this theory really true? Or does our strong belief in this theory cloud our vision? Does it stop us from exploring other possible origins of life? Listen to yesterday's 'A life with ...' for an interview with Lynn Margulius, biologist and professor in the department of Geoscience at the university of Massachusetts. Professor Margulius, in stressing the importance of symbiotic relationships between species, opposes to the very foundation of Darwin's evolutionary theory where there is always competition for survival.