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Once life emerges on a planet, what's the \textbf{probability that will evolve into intelligent life?}. Depending on the exact definition of intelligence, on Earth it has appeared probably at least a couple of times (\href{http://en.wikipedia.org/wiki/Cetacean_intelligence}{cetacean intelligence}). Also, given the Intelligence also gives a clear  evolutionary advantage of intelligence, it is plausible that and  it might  represents a common pathway of life\footnote{Note however that life. On the other hand, following the same reasoning used for $f_l$,  the fact that it took several more than 3  billion years for "intelligent lifeforms" life  to evolve on Earth has been used as an argument supporting from single-celled bacteria to Homo sapiens might argue for a  small values value  of $f_i$}. $f_i$. Overall this term is very uncertain; using  Frank Drake himself followed this line of thought and concluded that the factor optimistic guess one has  $f_i = 1$.However... (Jim's argument). Minimum ~Billion years. And could be much longer  To communicate with other intelligent life a civilization has to develope some sort of technology. If again we considerthe  Earth's case, this happened for humans but not, for example, for dolphins. The factor \textbf{$f_c$ measures the fraction of civilizations that develop communicative technology}. As intelligence and curiosity seem to go hand-in-hand, it seems conceivable that all intelligent lifeforms might eventually evolve towards a technological, communicative form. $f_c = 1$ Putting these factors into the Drake equation we get   $N \approx \frac{2}{3} L \approx L$. Note this is basically the same result that Frank Drake obtained in 1961! The difference is that this has been obtained only making assumptions on the factors $f_i$,$f_l$ and $f_c$, since the other terms in the equation are now established.