I think the earliest "life" would be the sperm, and whatever it is made up of. I think any organism, or anything that will become an organism, is worthy of being considered life. But I suppose you arent "human" until a certain point. I guess it just depends on what you consider life to be. In my eyes it doesnt have to be developed or intelligent, it can be simple and purposeless, but still be/have life. I mean, the human aspect of life doesnt come until down the road, but there are many stages that come before you are a human, and I consider those life just the same. They are equally important and necessary. Similar to the seed of what will one day be a flower.