Astrobiologists Find Ancient Fossils in Meteorite Fragments
technologyreview.com
technologyreview.com
Chandra Wickramasinghe is currently the MAIN guy promoting the idea discussed in the article kindly submitted here (as Hoyle has died). Hacker News participants can gain perspective on this idea by reading "Diatoms…iiiiin spaaaaaaaaaaace!"
http://freethoughtblogs.com/pharyngula/2013/01/16/diatomsiii...
and
"Chandra Wickramasinghe replies…and fails hard"
http://freethoughtblogs.com/pharyngula/2013/01/18/chandra-wi...
to see comments by a biologist on why the evidence here is completely inadequate for Wickramasinghe's latest claim. Wickramasinghe has been around the block with claims like this before, and he is the editor of the main "journal" that promotes this idea, but none of his specific claims of finding extraterrestrial life have ever been backed up by convincing evidence.
EDIT: I should add the link to a critique of the extraordinary claim here by an astronomer
http://www.slate.com/blogs/bad_astronomy/2013/01/15/life_in_...
(this was linked in the links I put in this comment earlier), so you can see his comments on the new claim directly.
By their fruits you shall know them. Sometimes it's appropriate to use a heavy touch. I would agree Myers relies on it much too much, but it's not inherently bad.
Though, as a minor point, Myers' site itself could use some better design chops...
Have you read his blog posts that aren't about atheism, or debunking, but are just about what he researches and teaches? Here's an example from today: http://scienceblogs.com/pharyngula/2013/03/11/what-i-taught-...
As far as I can tell, this evidence doesn't even begin to scratch at the surface of information needed to demonstrate or even really suggest that these were ever living organisms.
The nail in the coffin, for me, is the fact that this is set to be published in the Journal of Cosmology, a publication of questionable repute [2].
[1] https://www.technologyreview.com/sites/default/files/images/...
Images like this are effectively Rorschach tests. Sure, they may look like xenofossils to astrobiologists, but there are no doubt people to whom they look like their grandmother lying in a pool of blood...
Extraterrestrial life would be great? I'm not sure. I think the 2 most likely scenarios are: 1. ET would be far less evolved 2. ET would be far more evolved
#1 wouldn't be terribly interesting. So what about #2. What would that be like?
Well, we have some relevant experience from planet earth.
How do humans view/treat organisms that are far less evolved ... like bugs?
Any time someone says something like this, that's proof that they don't actually understand evolution.
Bugs have been evolving for exactly as long as we have. Bugs outnumber us, outweigh us, and there are ridiculously more types of them than there are of all kinds of vertebrate life.
We have been able to achieve an undue impact on our environment. But bugs are not less evolved than we are.
Let me add to the surprises. Most fish are evolved from air breathing animals. Our eyes contain a trivial design mistakes that an octopus does not. And we are more closely related to a goldfish than either is to a shark.
If any of this comes as a surprise, then you have confirmed my comment that you don't actually understand evolution.
Edit: Originally I said "land-dwelling" instead of "air-breathing". I do not know of direct evidence about land dwelling, however the swim bladder is believed to be evolved from a lung.
Even more importantly, bugs have been through many more generations than we have. If anything it is the bugs that are "more evolved".
That said, the amazing diversity of beetles suggests that some types of bugs have indeed been changing rapidly.
As with most things there is a nearly tower of progressively more accurate statements that could be made.
I wanted to check your source for this proposition, because after I upvoted your comment on other grounds, I wasn't completely sure that this squares with what I have read about evolution.
For example, this link
http://dinosaurs.about.com/od/otherprehistoriclife/a/prehist...
is to the contrary, suggesting that most fish living today had ancestors that were aquatic.
AFTER EDIT: To acknowledge your kind reply, I wondered if that was what you were getting at. To me, "land dwelling" implies, among other key behaviors, breeding and laying eggs on land. By contrast, "air breathing" would be a term unambiguous for what you meant, and still surprising to most readers.
Wikipedia claims that this is thought to have evolved as a survival method in oxygen poor water. My understanding had been that this was because their ancestors, however briefly, were adapted to survive out of the water. If only as well as today's lungfish.
My understanding may be wrong. But still, most fishes today are descended from air-breathing ancestors.
Reading the wiki link, it looks like sharks do not have this feature since there was a divergence prior to this. What this says to me is they probably were water dwelling but for some reason developed lungs (a short stint on land and went on to find their true calling in the water)? Or they could have started out mostly in shallow water or spent a lot of time near the surface.
>>>> EDIT More searching suggests that the picture is quite murky.
The swim bladder and lungs of aquatic and terrestrial organisms arose independently from a common primordial “respiratory pharynx” but not from each other...If there is commonality among these diverse respiratory processes, it is that all levels of organization, from molecular signaling to structure to function, co-evolve progressively, and optimize an existing gas-exchange framework.
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2895359/
<<<<
Also, surprise is trivially true given unknown data even if it properly fits one's model since no one follows all deductions of a model to generate all data. Plus, the brain tends to compartmentalize.
I won't be snarky. I'll just point out that evolution has multiple meanings and I think that it's obvious from context that in this case I'm using 'evolved' as shorthand for more intelligent/advanced/sophisticated.
Yes, but that's not what evolution means. Natural selection chooses the fittest genotype, not the "more advanced". The idea that evolution progresses from simple to complex is a myth -- a persistent myth, but a myth nevertheless.
Evolution isn't a program with a specific outcome, it's a blind algorithm that chooses the fittest genotype at every turn. If the "fittest" genotype is a cockroach, for example after a nuclear war, that's the outcome. Evolution doesn't care about our tastes because nature doesn't care about our tastes.
Biological evolution is only one of many meanings of the word evolution. (I promise, I'm aware that bugs have been biologically evolving for longer than humans.)
http://dictionary.reference.com/browse/evolution?s=t
1. any process of formation or growth; development: the evolution of a language; the evolution of the airplane.
2.a product of such development; something evolved: The exploration of space is the evolution of decades of research.
3.Biology . change in the gene pool of a population from generation to generation by such processes as mutation, natural selection, and genetic drift.
4. a process of gradual, peaceful, progressive change or development, as in social or economic structure or institutions.
5.a motion incomplete in itself, but combining with coordinated motions to produce a single action, as in a machine.
Just do a google search for 'spiritually evolved', 'evolved beings', 'evolved man' ... you'll see what I mean.
as I said, thought it was clear from context.
http://www.merriam-webster.com/dictionary/literally
1. : in a literal sense or manner : actually <took the remark literally> <was literally insane>
2. : in effect : virtually <will literally turn the world upside down to combat cruelty or injustice — Norman Cousins>
Read more here: http://arachnoid.com/wrong/index.html#Dictionary
> ... as I said, thought it was clear from context.
Not in any kind of serious discussion, with pretensions of accuracy.
In response to your assertion, it seems to me that with our advances in medicine it doesn't look likely that we're going to evolve greater intelligence. I would expect any species that evolves our level of intelligence will take an interest in medicine and arrive at basically the same steady state. So I'm going to make a completely unsupportable and useless from-first-principles prediction that intelligent life elsewhere in the cosmos will be approximately as intelligent as us.
I assure you, homo sapiens is under great evolutionary pressure to evolve an effective response to birth control.
It is also worth noting that it is suspected that our large brains mostly reached their present size to enable us to be more effective in interacting with each other. As long as we would prefer to not wind up alone on Saturday night, we'll be under pressure to better figure out how to get other humans to do what we want them to do. There is no upper limit to how much intelligence could be brought to bear on that problem.
(Though in practice I believe that we'll build machines smarter than us, which will improve far more rapidly than we could ever hope to.)
I'm not claiming evolution is finished. I'm claiming it is affected and I don't see compelling pressure to select for ever-greater intelligence. Even if I found your argument compelling, you're hardly talking about the same kind of intelligence as the GP. Intelligence is one of those squishy things that resists good formal definition.
And intelligence is selected for for reasons that are not addressed by modern medicine.
there is no design[er]
I think a better, and similar, comparison would be of intelligence. We treat less intelligent animals quite poorly for the most part. Hopefully the correlation between empathy and intelligence is universal and not just a trend among humans.
I hate to rain on your parade, but empathy and intelligence are selected only insofar as it supports survival and procreation -- only to the degree that it supports natural selection.
Empathy and intelligence are just neutral terms in a complex equation by which natural selection chooses the fittest genotype. They have no special standing, and a fair reading of human and natural history shows that, overall, they're not correlated with the survival of the species that possesses it.
Evidence? Count the number, or the biomass if you prefer, of the species that survive in a brainless, ruthless manner. Compare to those whose fitness is enhanced by empathy and intelligence. And remember that overall we can't be included in the intelligent, empathic column, at least not when we're doing our best to survive.
This evolutionary episode would have been a period of rapid adaptation, and amusingly is suspected to have been when our ancestors acquired a tendency towards religious belief. (We are the only known hominid with things like burial rites.)
Tangentially, #1 would be incredibly interesting to many people. We (the general public) have no definite indications that we /aren't/ on the only rock in the Universe with life, and #1 would hold great consequences.
The scary implication of #1 is that it updates our probability for long-term survival and becoming a technologically advanced, space-faring species: by _lowering_ it. That's because it pushes the potential Great Filter [1] closer to our present condition and increasing the odds that it's actually somewhere in our future.
Of course, this (i.e. civilization quickly become extinct) is just one possible resolution to the paradox, but the arguably simplest one. If the actual reason(s) we don't see advanced life are different, the Great filter hypothesis holds less water. We don't know that yet, though.
Now you might say that this is irrelevant. Just because we like other animals doesn't mean the aliens will. This is a good point, except that it completely invalidates the premise put forth of "experience from planet earth."
I have to believe that any organism sophisticated enough to find us would be amazed. They may be far more advanced, but seeing the lifelessness of space and the complexity of our civilization, anything with a shred of intelligence would be at least intrigued. Speculating on their nature and disposition is meaningless and arbitrary at this point.
So it's ok to go Ad Hominem against anything that contradicts our current knowledge? Ok, got it
http://journalofcosmology.com/Contents11.html
(Wickramasinghe is "Executive Editor, Astrobiology" for the Journal of Cosmology)
then you can see for yourself a bad sign about the strength of evidence for the paper.
See
http://en.wikipedia.org/wiki/Wikipedia:Identifying_reliable_...
for more details on identifying reliable sources.
AFTER EDIT:
The group blog Retraction Watch
http://retractionwatch.wordpress.com/
is an excellent glimpse into the world of scientific publishing, and shows how many low-ranking journals there are that are hard up for content. I think I learned about this interesting blog from another HN participant a year or two ago.
Of course I trust Nature more than, let's say "Bob's Journal about science stuff"
But sometimes even articles in Nature have been printed elsewhere first, (like a 'beta test' for the article - peer review nevertheless), usually in journals specific from the field (clarification below)
The "Identifying reliable sources" page is a Wikipedia policy, it has some good insights, but it is biased towards Wikipedia, see for example "Articles should rely on secondary sources whenever possible. For example, a review article, monograph, or textbook is better than a primary research paper"
Edit: Yes, journals usually don't accept content published elsewhere, my bad.
What happens is that, yes, you can't republish something 100% equal to something published elsewhere. (eg: http://www.ieee.org/documents/top10faq.pdf ) but while the research progresses you provide more detailed papers or focus on different areas of research
Not true. Republishing already-published work is specifically disallowed by Nature and most high impact journals. Doing so merits a retraction.
The whole point of scientific journals is to change our current knowledge, so that's not really a fair criticism of my dismissal.
Read even just the Wikipedia article and you'll see that this journal has several issues: (1) the quality of its peer review is questionable; (2) it appears to promote fringe views; (3) it has been widely criticized by the scientific community.
So yes, after criticizing the research itself, I also dug around and discovered problems with the journal it was being published in. I don't see anything wrong with doing so. Had the data looked less bogus I probably wouldn't have been suspicious enough to investigate the source.
Your point was that these features look as similar as other features and hence they should be the same.
Now, the given article really reads like a press release more than anything, but I don't remember if the original article had something else on the picture.
What I would think is that (but I am not sure) since these are electron microscope pictures, you can get a composition analysis of the sample from the microscope, hence being able to differentiate the features.
And no, I'm not taking this research too seriously as well, I just find it funny that some people jump at it and seem to dismiss it at first sight.
Phil Plaitt also has a pretty good critique[2], but if you have the background, reading that paper should be enough to at least make you squint hard at their "science". There's a reason that people don't take the group seriously, and it's not fear from the establishment or whatever nonsense.
[1] http://journalofcosmology.com/JOC21/PolonnaruwaRRRR.pdf
[2] http://www.slate.com/blogs/bad_astronomy/2013/01/15/life_in_...
If they had sufficient evidence to back up their claims then they would be on the cover of Nature. Unfortunately for them, actual Science requires peer-reviewed evidence. Publishing in your own journal does not count. It's a huge red flag.
In that light, looking at where something was published makes total sense. It’s a completely valid mechanism for non-experts to separate the crap from the good stuff. (Even experts, given all the stuff that is published all the time, have no time to read and evaluate everything on its merits. Increasing efficiency by centralizing that task and not forcing every scientist to do it all the time is more or less the purpose of journals.)
The name Anil Samaranayake caught my eye, since he's the the director of the Colombo Medical Research Institute.
Well, at least their publications are not behind a paywall, free for download:
http://arxiv.org/abs/1303.1845
so anyone can check the believability of this research themselves!
So I'd say it's too early to pull out the nails or the coffin, it is just an unverified theory right now. Those are a dime a dozen.
1. "In total, Jamie Wallis at Cardiff University and a few buddies received 628 stone fragments collected from rice fields in the region. However, they were able to clearly identify only three as possible meteorites."
In other words, the researchers weren't in on the collection activity, and may not possess the expertise to distinguish meteoritic material from ordinary earthly rocks (that determination is not easy).
2. "One stone, for example, had a density of less than 1 gram per cubic centimetre, less than all known carbonaceous meteorites."
And it didn't occur to these people that it wasn't a meteorite? Low-density meteors don't normally get to the ground -- they are much more likely to vaporize in the atmosphere. A low-density sample like this is immediately suspect.
Conclusion: Three identifications out of 628 samples, one of the three is not likely to be a real meteorite, terrestrial contamination cannot really be ruled out, and this work is neither refereed AFAIK nor published in a normal scientific journal. I call shenanigans.
Reference: http://arxiv.org/abs/1303.1845
General HN comment consensus is that the article is terribly poor science, published in a crank journal.
"There are other explanations, of course. One is that the fireball was of terrestrial origin, a remnant of one of the many asteroid impacts in Earth’s history that that have ejected billions of tonnes of rock and water into space, presumably with biological material inside. Another is that the structures are not biological and have a different explanation.
Either way, considerably more work will have to be done before the claims from this team can be broadly accepted. Exciting times ahead!"
https://en.wikipedia.org/wiki/Allan_Hills_84001
From the wiki article: '[T]he scientific consensus is that "morphology alone cannot be used unambiguously as a tool for primitive life detection."'
But let me know when they find a skeleton fossil in a meteorite.
There is a lot of jumping the gun in these articles, especially when it's the lead authors first and only paper. Here is a link to the actual paper:
http://arxiv.org/ftp/arxiv/papers/1303/1303.1845.pdf
Here is a slate article that has already proven that the data mined by the "Astrobiologists" is faulty and biased:
http://www.slate.com/blogs/bad_astronomy/2013/01/15/life_in_...
As you say though, it's not good in the billions.
You can still use radiological dating with other elements (e.g. Uranium).
>if it turned out to come from the future
I don't even…
>> if it turned out to come from the future
> I don't even…
have a sense of humor? It is certainly possible if we had a extra-terrestrial organic matter (which we don't) that it could test as coming from the future based on carbon ratios, though obviously it would not actually be from the future - thus "on that scale".
I'm not sure if the same applies to Uranium radiological dating.
When you find a fossilised rabbit in the meteorite, call me.
Even if it was true, couldn't it have been organisms from earth ejected into orbit after a meteor strike and, thousands of years later or more, falling back to earth?
Now if we find a definitive proof of panspermia it would be the biggest discovery ever made by mankind so far...
That would still be a hugely significant result.
We expect a higher density of biologically contaminated samples near the Earth. This is perfectly compatible with (but does not prove) panspermia.
The key question isn't whether space is sterile, but whether space is aseptic. That's harder to demonstrate.
To illustrate the difference, imagine a doctor scrubbing for surgery. It's impossible to scrub your hands until there's a population of zero pathogens, but fortunately that is unnecessary. You just need to reduce the population enough that the few organisms that remain just can't get a foot-hold.
We're in the back waters of the galaxy in a mature star system. Even if panspermia were rampant in the galaxy, we probably wouldn't see it. Stellar clusters, nebulae, Bok globules, and young star systems are where you would expect this kind of action.
Mechanically speaking panspemia is just diffusion, except instead of Brownian motion you have impact ejecta and gravitational evaporation. Each of these events has a probability curve. You could even construct your own "Panspermia Drake Equation", something like:
P = N_seed * R_ejection * Pop_specific * f_survival_ejection * f_escape
* 2^-(T_encounter / t_1/2_cruise)
* f_habitable * f_survival_reentry * f_germination
P = rate of panspermia in a given volume of space
N_seed = number of seed (life-bearing) bodies in that volume
R_ejection = average rate at which mass is ejected from each
seed body (kg/yr)
Pop_specific = average specific population ('von Neumann'
individuals/kg) of ejected material
f_survive_ejection = fraction of population that survives ejection
f_escape = fraction of ejected material that eventually escapes from
the stellar system, either due to initial velocity
or long-term orbital perturbations
T_encounter = average length of time before an escaped
object encounters another body
t_1/2_cruise = half-life of population exposed to interstellar conditions
f_habitable = fraction of encountered bodies that are habitable
f_survive_reentry = fraction of population that survives reentry
f_germination = fraction of the population that actually germinates
Of course, The number of seed bodies (N_seed) is the interesting part. This allows the equation to feed back on itself. Waaaaaaay out here in the Solar neighborhood, everything's so far apart that T_encounter rate limits that feedback to effectively zero, but in stellar clusters and nebulae you can find regions with dozens of stars per cubic light-year. As stars move within the galaxy they might experience different rates of panspermia – perhaps long lifeless intervals punctuated by "bursts" of bombardment, or maybe just once (in the conditions of the stellar nursery) and then never again.
When it comes to panspermia as an origin theory (aka exogenesis) I consider myself a "weak atheist", if you will. The meager evidence we have seems to suggest that life on Earth originated in abiogenesis, not panspermia. That doesn't mean that panspermia does not occur.