This past Sunday morning, I read a brief news item about the recent claim by a respected astrobiologist of “ancient alien bacteria” — similar to certain cyanobacteria found here on Earth — found in three different carbonaceous chondrites, which are very rare meteors…
So, I read the paper (quickly), took some notes, saved some photos, and wrote up the story. And I noted then that the news was certain to create excitement and controversy — which it certainly has. And also, quite a bit of distancing (by NASA, and some prominent science journalists} and repudiation. Admittedly, I was a bit jazzed by the news and so I put aside some of my normal skepticism.
I have provided links to various articles/comments on this discovery at the end of this post. However, I want to add some thoughts on this topic as well as on a related topic — the origin of Life.
Most of the journalistic criticism of this paper (apart from its numerous typos) centers on the Journal of Cosmology itself, which is a non-print, non-peer-reviewed journal that some claim is mostly a rubber-stamp publisher for cranks. A few writers noted that the journal is “failing”, to some extent, and blame the appearance of this paper on some last ditch effort to launch a salvo into the sanctuary of establishment science. All of which may or may not be true, but none of this criticism constitutes a scientific investigation. These are all forms of ad hominum commentary — attacking the source, not the data/claims.
A few of these articles deride Dr. Hoover for his past advocacy of what’s known as “panspermia”, or the theory that life on Earth originated in outer space, and was “brought” here by comets or meteors (or, in some more radical views, by aliens). It is mostly considered a fringe theory, but it has enough “respectable” proponents that it doesn’t quite get tossed into the scrap heap of theoretical musings.
Now, I don’t personally subscribe to this theory; as any one who reads my posts knows (including the original “alien microbes” post), I have frequently spoken of biogenesis and various theories on the origin of Life (here on Earth). I believe that Life on Earth originated on Earth. I base this on over two decades of research on biogenesis (starting with the Cairns-Smith hypothesis of self-replicating clay crystal templates).
Now, just in the past five years, or so, there has been some progress on this question of how Life evolved from non-animate matter.
Some of this research involves the discovery of cross-catalyzing enzymes which make copies of themselves and then are able to evolve on their own (Lincoln and Joyce). Meanwhile, in support of what’s known as the ‘RNA World’ hypothesis of biogenesis (i.e., RNA evolved before DNA), Lambert et al have revealed a silicate-mediated formose reaction, indicating a “bottom-up” synthesis of sugar silicates (enabling the formation of ribose, the sugary backbone of RNA and DNA).
What’s more: bio-engineers Robertson and Scott have demonstrated ribozyme-catalyzed self-assembly of RNA (via L1-Ligases). And, there is also the compelling theory expounded by Michael Russell involving the chemo-mechanistic replication of iron-nickel precipitate “bubbles” around deep sea thermal vents as a viable “home” (an analogue membrane, if you will) for self-replicating, biogenic molecules.
There is no doubt more experimental work being done as we speak, and all of it is building towards a viable theory of biogeneis that, I am confident, will be proven in my life time.
There’s just one problem: so far, while there is some good work being done, while we know that self-organization precedes self-replication…no one has yet demonstrated (complete) biogenesis in the lab, nor articulated fully a scientific theory of how living cells evolve from inanimate constituents.
Sure, there were the famed Miller-Urey experiments of 1953 (actually repeated and confirmed in 2007) in which a charged mixture of methane, ammonia and water produced adenine (one of the four nucleotide bases of DNA and the basis of the energy storage molecule ATP). However, these adenine molecules were not self-replicating, and researchers are not sure how these were formed, exactly, either. The search goes on.
The point of all the foregoing is this: because we have this HUGE question on the origin of Life lingering in the background of the biological sciences, there is also an intellectual vacuum into which all manner of “panspermian” and/or alien origin hypotheses may rush.
And I will admit, there is a strange awe and “coolness” to such fringe theories; they are intriguing and evoke a sense of cosmic mystery. And even a respected scientist can fall under their speculative spells. It is possible that Life did originate far off Earth (glycine, an amino acid, has been found in comet dust), or, by meddling extraterrestrials. How marvelous to contemplate!
But it need not be so mundane an alternative to look for Life’s origin here on Earth, where it most likely had its birth. The Earth is an amazing planet! It produces amazing lifeforms (including us) that command our admiration and awe… and our science. How marvelous to live on such a planet…
And, as noted in my original post, even if these microbes are “indigenous” to the meteorites in which they were found (and thus presumably transported here from somewhere else), this fact would not solve the riddle of Life’s origins. The HOW of creation.
The mystery remains.
I will leave the (no doubt) weary reader with that to chew on. Getting back to Dr. Hooper’s controversial claims, I herein include the Knight Science Journalism round-up of relevant articles and comments, courtesy of Charlie Petit (text by Mr. Petit):
(the original story) Fox News – Garrett Tenney: Exclusive: NASA Scientist Claims Evidence of Alien Life on Meteorite
AP – Seth Borenstein: Scientists skeptical of meteorite alien life claim;
Bad Astronomy via CBS – Phil Plait: Alien life evidence? No so fast. Where we are told it’s bad and suspicious form for a paper to declare as unalloyed and unhedged fact what ought to be surrounded, if the author wants to be taken seriously, by a dense cloud of maybe.
Reuters – Deborah Zabarenko: Strange life signs found on meteorites: NASA scientist ; A cautious report that does not appear to have benefited from many, or any, calls to outside astrobiologists.
Space.com via Chr. Sci. Monitor – Clara Moskowitz: Alien fossils found in meteorite? Scientists urge skepticism ; Hmmm. She has, amid the scoffing, NASA’s Chris McKay saying he thinks they’re from space, too. Really?
Time Magazine: Michael D. Lemonick: Alien Life discovered in a Meteorite! Or Maybe Not ; As he writes, “a little history lesson is in order,” including previous misadventures in astrobiology and the Journal of Cosmology where the paper appeared. An even more telling take-down of the journal, which Lemonick (thank you very much) also links to, are in the next bullets down.
Somatic Marker (blog) David Dobbs: Journal of Cosmology Going Out with Big Bang ; Turns out the journal’s on its last legs, and its publisher is tossing fireballs at the powerful evil forces that done it in…
Neuron Culture (blog) David Dobbs: Aliens Riding Meteorites: Arsenic Redux or Something New?:
top image: (‘panspermia’) Silver Spoon Sokpop ; cc – by – sa 3.0
second image: Helix84 ; cc- by – sa 3.0
third image: (DNA nanostructures) ayacop; Thomas H. LaBean and Hao Yan
bottom image: Rasmussen29892