November 22, 2013

Frequently Asked Questions

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Q: Why would a civilization take up cosmic seeding?    [Top]
A: To backup and spread life. Don’t you agree it is a good thing to do in a vast and inanimate universe? Within our own civilization such program has already been  proposed (see also here).

Q: Why would they insert a signature into cells?    [Top]
A: If some of the seeds end up on a suitable planet, they may ultimately lead to the evolution of an intelligent species. If that happens, don’t you think it is a good idea to provide those species with a clue about their descendant origin and to let them know there existed other intelligent beings in the universe? The only possible “time capsules” in this case are the seeds themselves; sending an external (passive) artifact is of no use, as it will be lost or/and disintegrate long before intelligent species might evolve.

Q: If we are created by aliens, then who created the aliens?    [Top]
A: bioSETI does not assume that we are “created by aliens”. In fact, cosmic seeding aims at securing/spreading the existing native life-form. Furthermore, since the senders and the seeds’ descendants share common cellular ancestry, the very word “aliens” is a misnomer in this case. (Admittedly, inserting a signature into a cell implies the cell is modified to some extent; still, there is an enormous complexity gap between such modification and creation of life from scratch.) As for where they came from – they could have originated locally on their planet through abiogenesis, or they could themselves descend from cosmic seeding by an even earlier civilization (but ultimately, first life must have started somewhere from scratch, of course, since the age of the universe is finite).

Q: Is the message encoded in human DNA?    [Top]
A: Yes, but it’s more than that. First, it is encoded in DNA indirectly; technically, it is encoded in the genetic code. (The term “genetic code” is  often used in mass media to denote the sequence of DNA, but that’s misleading – the correct term for that is genome. Instead, the genetic code is a set of rules that assign 64 nucleotide triplets to 20 canonical amino acids). The genes of the molecular machinery that implements the genetic code come from genome, and only in this sense the message is encoded in DNA. Second, since the genetic code is universal for all terrestrial life, it is not only about humans – the message is encoded in every living cell on Earth (including bacteria, plants, etc). As for encoding non-biological information directly into DNA sequence, it is rather straightforward (even with today’s techniques here on Earth), but is of no use in seeding because biologically inactive DNA segment with a message will mutate beyond recognition (or even will be entirely eliminated by selection) long before intelligent species might evolve.

Q: What does the message say?    [Top]
A: It says: “To whom it may concern: we were here“. Well, of course, this message is not written in English, or in any other human language; in fact, it is not even a sequence of letters and words. The message is written in the language of logic and mathematics; it represents a delicate structure of attributes that ultimately encode some of the most prominent universals of culture – the zero-based positional notation and, independently and explicitly, the notion of zero as a number in its own right. You may find these not very special, but that’s because you are so accustomed to them, as they’ve been ingrained into our culture. In fact, however, discoveries of zero and positional notation (which happened independently in several human cultures) were pivotal historical events that ultimately triggered the scientific progress and development of computing technologies. It is important to realize that, unlike, e.g., mathematical constants,  positional notation and the notion of zero live within culture, not within natural world (nature cares about quantities, but not about how intelligent species decide to encode quantities). So if there is a need to bring attention to an intelligent intervention (a kind of “we were here” message), the option of choice is to encode most universal codes of culture, and the zero-based positional notation is exactly that.

Q: How is it different from the Bible code and stuff?    [Top]
A: Yeah, it’s so irresistible for some people to draw the analogy with the Bible code here, suggesting that “if you look hard enough, you can find interesting patterns anywhere”. This analogy is irrelevant. First, in case of the Bible code there is no scientific hypothesis to constrain/guide the data analysis as such (while bioSETI follows from the seeded-Earth hypothesis proposed by Sagan, Crick & Orgel). Second, this analogy is inappropriate statistically, because the Bible is millions of letters long; in contrast, the genetic code is just a few hundred bits, and there is only a handful of methods to uniquely partition it without referring to the actual mapping between amino acids and codons (after which the application of the actual mapping might or might not reveal “something interesting”). It is one thing to find patterns in a very large book, which is only one among very many existing books, and written in one of the many existing writing systems. It is something different to look at the only existing Rubik’s cube to see that it happens to be solved, with all its facets containing a single color.

Q: Might it count as evidence for God?    [Top]
A: No, unless you believe that an omnipotent God (whatever that might mean) would decide to reveal itself through a “miracle” which could be engineered by mere mortals just as well. Technical challenges notwithstanding, there is nothing supernatural in embedding a signature into the genetic code (and in bringing microbes to other planets). In fact, minor artificial modifications of the code are now routinely performed in laboratories on Earth for other purposes (e.g., to design proteins with unusual properties).

Q: Might it lend support to Intelligent Design?    [Top]
A: No. In fact, Intelligent Design (ID) and bioSETI proceed from premises which are diametrically opposite. The very gist of ID is in arguing against natural evolution. By contrast, bioSETI adopts natural evolution as a premise, and strives to consider how a signature might be encoded into cells such that it could remain unchanged while cells multiply and evolve. Not only bioSETI does not contradict evolution, but the very idea of storing non-biological information in living cells is based on the natural mechanism of negative selection. Thus, a bioSETI signature is in fact a bad news for ID, as it implies validity of the premise ID claims to be false.

Q: Might it lend support to Raëlism?    [Top]
A: No. Even though Raëlism is self-proclaimed as science-oriented, it is still a religion – you have to believe what a single person says, without any evidence provided. After all, if life on Earth was “scientifically created” by advanced extraterrestrials who came here, what’s so special about Raël that they would secretly inform him about that? Besides, there are inconsistencies in the game. E.g., microbes were present on Earth at least 3.8 billion years ago (the evidence is ample and comes from multiple independent sources, so there is no doubt about that). Yet, humans appeared just yesterday, in geological timescale. Doesn’t seem to be what advanced elohims were after, they just had to wait billions of years before sending their messengers in the form of Buddha, Jesus, and others. And if it is not a problem for them to send live messengers speaking human languages, why bother about inserting a small signature into the genetic code at all?

Q: Might it lend support to the simulation hypothesis?    [Top]
A: Doubtful. If you simulate an entire universe with intelligent species within, you are in full control and have a lot of straightforward options to message them (you may even draw “Hi!” in the sky). Compared to that, messaging through the genetic code is a rather involved and intricate choice. It does make sense in cosmic seeding (because, in fact, it is the only available option there). It hardly makes sense in simulation. (Of course, if you stick to the simulation hypothesis, you still have an option that life on Earth was seeded by an earlier civilization, but all of that had happened within a simulation 😉 .)

Q: The genetic code is in fact not universal – doesn’t it contradict your conclusion?    [Top]
A: Actually, it supports our conclusion, because none of the known variations of the genetic code, when analyzed within bioSETI approach, reveals systematic precision-type attributes of any type. It is commonly accepted that these variations emerged from the canonical code via its modifications during evolution (no matter how the canonical mapping came to be in the first place). If life on Earth descends from cosmic seeding, you would expect that an intact message should sit in the original version of the code, while in subsequent evolutionary modifications the message is broken or even erased completely. This is exactly what is observed.

Q: Isn’t the genetic code too small for a distinctly intelligent signature?    [Top]
A: The genetic code is a few hundred bits in its informational capacity. While this is not a particularly large storage to allow a full-fledged “message”, it certainly suffices for a signature whose sole purpose is to provide indication of intelligent intervention (a kind of “to whom it may concern: we were here” message). Just for comparison – analogous amount of bits allows to encode the first 35 prime numbers, or value of a fundamental constant with an accuracy of 10-60.  In fact, this capacity is even comparable to some Earth-made SETI-messages, e.g., the 551-bit test message composed by Frank Drake.

Q: Is it possible to seed an exoplanet many light years away?    [Top]
A: Theoretically, yes. Practically, though, this might be very challenging and hardly doable without some form of artificial intelligence. But probably there is no need to seed individual exoplanets at all; instead, the seeding might be targeted at star-forming regions which are huge, so automated probes can easily get into them even with primitive navigation technology. Besides, this strategy has another advantage. The molecular clumps collapse into star clusters comprising up to a few hundred and even thousand stars (with their planets), which are then dispersed throughout the Galaxy very quickly (by geological and evolutionary standards). So launching a single probe is enough to get many potentially seeded planets. It is now known that most stars are formed in a clustered mode, and, incidentally, our Solar System is also believed to have formed in an open cluster. So, if terrestrial life descends from seeding, it probably goes back to seeding the original protocluster, rather than Earth individually. In this case we may expect that the lost siblings of the Sun might host planets with our cosmic cousins, even if only in microbial form.

Q: Was there enough time for a civilization to evolve before Solar System formed?    [Top]
A: Just a few years ago the answer to this question was rather uncertain, but recently there were a few discoveries of potentially habitable exoplanets as ancient as 11 billion years old, which is 2.5 times older than Earth. So the answer is – there was more than enough time for a civilization to evolve. As the authors in a paper in the Astrophysical Journal write, “… Earth-size planets have formed throughout most of the universe’s 13.8 billion year history, leaving open the possibility for the existence of ancient life in the Galaxy.”

Q: Didn’t PZ Myers refute your claim in his blog?    [Top]
A: With all due respect to PZ Myers’ secular/educational activity, in this case he had overdone it, which might be understandable because he learned about our Icarus paper via Intelligent Design folks who praised it believing it supports ID, so PZ attributed us to ID-proponents as well. He then attributed the entire thing to numerology like the Bible code, as a short way of saying that our data is the result of arbitrary “juggling” until we found some “desired patterns”. Though we admit that partly such response might be due to insufficient level of presentation in the Icarus paper (which we hope to compensate for in our new paper), to larger extent this response is due to PZ’s mere inaccurate reading. The latter might be seen, e.g., from the fact that PZ brings arguments from a (popular) book by Nick Lane, without noticing that in the Icarus paper we cite the original research described in that book. He also writes that we “did not rule out the operation of natural law”, but never mentions the large Appendix on statistical test which is devoted exactly to that (so probably he even didn’t get to the appendix). Or consider PZ’s statement that we are “juggling highly derived quantities that have little to do with functional properties of the molecules”. PZ missed the very point here – we envisage the possibility of encoding/decoding non-biological information via biological media, so no surprise that we consider parameters best suited for this purpose (namely, those which have the highest Shannon entropy) – so what of that if they happen to have little to do with functional properties? We could go on with examples, but it’s kind of boring. The point is – we all have biases, and PZ is not an exception. After all, would you also agree with him that Elon Musk is a terrible human being? 😉