| Can't speak to likelihood of discovering life on Europa but it would be fucking awesome. To be clear, microbial life in no way entails higher life. It's only by the insanely chance event of the eurkaryotic cell emerging that sophisticated multicellular life became possible on earth. Even if life is common in the universe, sophisticated multicellular life is extremely rare. The selective pressures on bacterial life favors small size and rapid reproduction, jettisoning any unnecessary genetic material. Mitochondrial ancestors relieved those pressures in a couple ways. Once the eukaryotic cell developed, multicellularity has evolved several times. All the cool things (multicellularity, eyes, flight) have evolved independently a bunch of times, and the eukaryote has happened only fucking once. Here's a deeper explanation of why it's so rare: http://rstb.royalsocietypublishing.org/content/368/1622/2012... Even if life is common in the universe, multicellular life is extremely rare because the evolution of eukaryote-esque organisms is extraordinarily rare and chance. Edit: That is to say, there's a strong case that step 4 is the Great Filter: http://en.wikipedia.org/wiki/Great_Filter#The_Great_Filter |
Honestly, me neither. I'm just a software engineer who is excited about space and hopes for the best. =)
> but it would be fucking awesome.
Wouldn't it? Holy hell, that would be wonderful. I hope it happens soon. Discovering life on Europa would be our generation's moon landing.
Thanks for the clarification. My knowledge of biology is limited, so I imagined each step (crude self-replicating molecules -> sophisticated DNA -> the cell -> etc.) being roughly as unlikely as the next. I had no idea eukaryotic cells were such a massive jump.
Earlier today I was watching a documentary about the Kepler telescope's search for exoplanets[0] that estimated the number of planets in our galaxy at 10^19. So many of those planets are unsuitable for any life, microbial or otherwise, but such a large number fills me with hope that the unlikely miracle of eukaryotic evolution could happen more than once. Then again, there are very plausible interpretations of the Drake equation[1] that pin the number of intelligent civilizations in our galaxy to less than 5...maybe even 1...so who knows?
[0]: https://www.youtube.com/watch?v=DD6QHP9ouuU [1]: http://en.wikipedia.org/wiki/Drake_equation