I don't think the powerball comparison is valid, mainly because while it is unlikely that you will win the powerball with one ticket, the comparison doesn't hold up because there literally may be billions of "tickets" out there, and life is holding all of them, tickets meaning worlds with similar conditions to ours.
The power ball analogy isn't so much about "what" life might be holding, but how and when. A person who plays the power ball has to select a specific sequence of numbers -- in the case of life, events -- that have to be drawn in a very precise way, and hope that outside factors -- the absence of any other winning tickets, or, with life, the absence of any events being different than here on Earth -- come together to win the complete jackpot. Life needs those exact same, precise factors to win the "Earth" jackpot. Unlike power ball, however, there is no controlled drawing of numbers or factors. There is a completely random soup of possibility, with many different components that can come together in an uncountable number of ways. There are no truly universal forces at play in the way these things come together.
Couple of problems.
Firstly, "compounds that are similar to nucleic acid" is not interchangeable with "DNA," and not one of the scientists in the story said anything about finding DNA, anywhere. What they found were biologically useless structures similar to those found in nucleic acids. DNA is a nucleic acid, and that's about as close as that link gets.
Secondly, understand that nobody is arguing against the idea of alien life, here. In fact, they're trying not to argue, at all. Still, what's being argued against is the likelihood of a creature forming on another planet with Earth-like morphology (humans, or any other creature). Having the components for the beginning of life, which nobody is arguing aren't out there, is an infinitesimally small piece of that overarching puzzle of probability.
All the meteorites suggest is that the building blocks are out there, but they don't tend to come together in any useful way, much less exactly the same way they did on this planet. Statistically, they'd have to come together to form something useful, somewhere, at some point, but the chances of that happening with all the same chemicals and all the same timing and all the same evolutionary circumstances (each being its own, uncontrolled lottery) is impossible.
I also have a distinct feeling that the phrase "we know [these compounds] will form in space," is far less exciting to this particular discussion than it sounds.
And it becomes more and more likely that possible sentient life elsewhere in the cosmos may look extremely similar to us. Panspermia, if it's true, would virtually guarantee that we would be made of the same materials, the only difference would be the individual environments that we had to adapt in.
Evolution doesn't have goals. Intelligence is not the highest level of evolution or the supreme state of being in the universe. It is not the end of a structured series of events. It's one, arbitrary link in a thoughtless chain of infinite possibilities.
Natural selection isn't just the adaptation to an environment, it's the adaptation to a specific set of scenarios and circumstances that take place in a specific environment (more uncontrolled lotteries). Even on Earth, in 13 billion years of molecule-to-life development, the conditions that required our brand of intelligence -- as opposed to tiger or humming bird intelligence -- have only come about one time, and our ancestors were lucky enough to survive that need and adapt. These conditions include the environmental changes that caused our earliest ancestors to come out of the trees, the environmental changes that caused the ice ages, which shaped our evolution further, and even the very specific flora and fauna we developed right along side, which shaped our needs and requirements for survival. There is absolutely no reason, what-so-ever, to infer that, without these very specific set of circumstances, human-like intelligence will develop, given that, without these factors, it never has on the very planet where the soup came together in a way that we know, beyond a shadow of a doubt, that it's possible, let alone human-like morphology.
he Power Ball analogy isn't quite accurate, and for more reasons in addition to Maudib's. First of all, evolution isn't a completely random process. It is dependent on environmental factors.
In my response to Muadib, I explained how the only factor making the power ball analogy slightly inaccurate, is the fact that it is controlled, and thus not as random as the factors that make up the entirety of evolution and how those factors impact natural selection.
I'll say that you guys also seem to be getting hung up on natural selection, and using it as an interchangeable term for evolution. Evolution requires natural selection to work as a theory, but the two concepts are different things. Evolution is the theory that natural selection leads to the development of species over time through a process of biological trial and error in an arena of otherwise random factors. Natural selection is the principal behind the rate of survival amongst those involved in the trial and error game, which is less random and determined by very specific developmental factors.
Regardless, before life begins to compete for survival, molecules have to compete for survival. The factors that determine survival are specific to each scenario (for which there are infinite possibilities)
, the factors that make up those scenarios (including environmental factors) are very much random. Even at that early stage, life has to develop just as it did here on Earth, meaning all of the power ball lottery factors need to be true in the precisely correct way, for the creatures to share developmental likenesses with Earth creatures. As the meteors from Muadib's link suggests, even that early stage of development doesn't come together quite right for Earth-like genesis.
Our ultimate common ancestor is the universe itself, which we assume distributes the same physical components and governs by the same rules pretty much everywhere. As Maudib pointed out, it's been known for a long time now that the basic building blocks of life as we know it are found in space rocks.
As for the universe as the common ancestor, without sounding too harsh, that's just rhetoric. It's true in a poetic sense, but not in a literal sense. While the components that made all of the precise scenarios that took place on Earth possible are everywhere in the universe (most likely), the forces that bring them together are not as controlled, predictable, and streamline in an open environment as you seem to believe them to be. Earlier we had a discussion about how there are some things that it is difficult for science to fully understand -- that's a big part of why. In this case, carbon, nitrogen and hydrogen can make a vast array of molecular combinations, in turn, those molecular chains can make up an even larger array of larger chains. As Muadib's link points out, those chains tend to be useless.
The compounds found in the space rocks were not building blocks for life. They were biologically useless compounds that are made out of the same stuff that makes up some of the biological materials on Earth.
Stepping outside of science for a moment and presupposing that these compounds found in the space rocks could be applied to building life on other planets, just useless biologically on Earth, we'd still run into the problem of gelling how these very different compounds would evolve into cells and then into creatures with even vaguely similar biological needs to our own, and thus experience natural selection in the same way, even if they had actually developed in our place, with all the right environmental changes and random factors, here on Earth.
The only real factors that would inhibit similar life forms from evolving elsewhere are dissimilar environmental conditions. However any solar system that evolves similarly to ours will probably have similar planets and similar planets will have similar conditions, and from similar conditions we can expect similar life forms to evolve.
They couldn't just be similar, they'd have to be precisely timed and exact.
This is evidenced by the fact that we are the only species on the planet (even being open to the idea that, for some reason, despite millions of years of evolution to the contrary, great apes could develop human-like intelligence and ditch their ape brand of intelligence which enables them to survive perfectly well) that have experienced just the right series of random scenarios that led to the naturally selected condition of human-like intelligence -- after 13 billion years of cosmic development from molecule to man. That's ignoring, as I mostly have been, that a brain that runs human-like intelligence is just one piece of a gigantic morphological puzzle.