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?
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.
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.)
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.
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.
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.
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.
there is no design[er]
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.
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.