A research paper on the emergence of life on Earth-like planets titled "Abiogenesis: the Carter argument reconsidered" has been published in the journal International Journal of Astrobiology.
Daniel Whitmire, a retired astrophysicist and current mathematics teacher at the University of Arkansas, has challenged a long-accepted argument by astrophysicist Brandon Carter. Carter argued that the existence of life on Earth is, at best, of neutral value regarding the possibility of life on similar, Earth-like planets elsewhere. In other words, because our awareness of Earth and the life on it hasn't come about by selecting it at random from the collection of all Earth-like planets, Earth and its life can't be considered typical.
However, Whitmire's new theory suggests this is faulty logic. Whitmire used what he calls the conception analogy to show that abiogenesis, the emergence of life from inorganic matter, is likely quite possible on Earth-like planets. Whitmire explained that "one could argue, like Carter, that I exist regardless of whether my conception was hard or easy, and so nothing can be inferred about whether my conception was hard or easy from my existence alone." In this analogy, hard and easy refer to the use or lack of contraception, and both are assigned values in his calculations.
"However, my existence is old evidence and must be treated as such. When this is done the conclusion is that it is much more probable that my conception was easy. In the abiogenesis case of interest, it's the same thing. The existence of life on Earth is old evidence and just like in the conception analogy the probability that abiogenesis is easy is much more probable," Whitmire continued.
You can read more from the paper here.