Has anyone ever thought about the irony of the way we use the word ‘life’?

For example, I’m studying Astronomy right now. Scientists state that the evidences show that there was life on earth at least 3.5 billion years ago. This life was in the form of microscopic organisms. This scientific evidence shows that life has been around on planet earth for at least 3.5 billion years (Bennett, Donahue, Schneider, & Voit, 2007, pp. 709, 710).

On the other hand you have people who still want to claim that the zygote in the womb of a living human does not constitute ‘life’.

Does there seem to be some inconsistencies here? I think so!

References

Bennett, J., Donahue, M., Schneider, N., & Voit, M. (2007). The Cosmic Perspective 4th Ed. San Fransisco: Pearson Education, Inc.