That's a good question. I can imagine that there was a time before there was life on Earth, and then clearly there was a time X-hundred thousand years or a million years later when there were things that we would all recognize as biological.
A high count indicates the presence of inflammation in the body. Because white blood cells are calculated by the number of cells per volume of blood, test results can vary between labs. Different labs use different degrees of measurements for the white blood cell count.
An elevated white blood cell count could be caused by a viral, bacterial or a parasitic infection. When the body is fighting off infections, the bone marrow works overtime to release more white blood cells. This is a normal immune-response to protect the body from pathogens.