/sci/ - Science & Math

[Anonymous No.3600030]

I've heard Carl Sagan was optimistic when it came to Aliens, so I hope I'm not being unscientific by suggesting that they might exist somewhere out in the universe. I'm not that scientifically literate, hence referencing a pop-scientist like Carl Sagan. I'm a Journalist, and I imagine bringing up Carl Sagan on these forums is just as tedious to you people as when hipster's at parties hear I'm a Journalist and start talking to me about Fear and Loathing. Shit, they don't even talk about Fear and Loathing on the Campaign Trail, they talk about Las Vegas, which contains about 10% actual factual journalist reporting.

But I digress: Say Aliens exist, what are the chances we've seen something similiar to them before?

By that I mean, a lot of weird shit evolves on Earth in a lot of different ways for a lot of different reasons. Frill-necked lizards evolve the ability to skitter swiftly over the sand so that he doesn't burn his feet. And lizards/snakes generally have biological functions evolved for hot, dry, climates.

Now, does this mean we should expect any life from a desert planet to be lizard-like? Or does it simply mean there are a myriad of lifeforms that could function in a desert and squamata is simply one order that has evolved on our planet?

TL;DR: Is it likely Aliens will be biologically and aesthetically similiar to a lot of animals on this planet?

[Anonymous No.3600070]

>>3600030
So many species on this planet are aesthetically different already. Would it be reasonable to assume that a species that came from completely different conditions ended up like a species from this planet? No, it would not
I'd say that it also depends on what the other planet is like.

[Anonymous No.3600101]

>>3600070
I think it is pretty likely alien life would be like life on earth, if it was a planet like earth. I'd think efficient strategies for survival wouldn't be particularly divergent.

[Anonymous No.3600111]

WHAT ARE THE CHANCES OF THEM EVEN EVOLVING DNA OP?

Chances are you could make life out of some other code broski.

[Anonymous No.3600119]

At risk of being too equivocal, it depends on how "similar" you mean and in what ways. There would likely be some similarities in overall morphology, as there are a few features that seem to function uniquely well as adaptations to particular environments. One way to get a general idea of which features these might be is to look at distantly related organisms that share the same sort of habitat. Features they share that were not likely present in the common ancestor are called "convergent." It's these "convergent" motifs that alien life might well rediscover.

That said, while there may be resemblances between Earth life and alien life, there's no reason to suppose that alien life would resemble *present* life on Earth any more than life existing in Earth's past. Sea scorpions, pterodactyls, trilobites, ammonites, lycopod trees - all were successful forms of life that alien life-forms might come to resemble.

[Anonymous No.3600121]

Yes. If their planet is similar to ours then yes.

[Anonymous No.3600149]

>>3600070
Some animals are named after other animals. Example: Hemaris, AKA, the Hummingbird Moth. Do you know why we do this?

Convergent evolution, mostly. The fact of the matter is, we only know of one way in which life can come about and we know of only a few conditions under which life can thrive. So I'm not so much expecting things from completely different environments to Earth's to evolve in a similiar fashion as stuff on Earth. Rather, I'm expecting things from a completely different location, but similiar environment, to be somewhat similiar in some ways to Earth animals and have a biology that can be compared the biology of Earth animals (IE. The Alien sphluctrap might be located in the throat, but perform the same function as the heart).

[Anonymous No.3600165]

>>3600111
>Chances are you could make life out of some other code.

Really?

As far as I know the jury's still out on abiogenesis... so... how can you know the probability that other building blocks of life exist when we don't even know how the ones we know of came about?

[Anonymous No.3600205]

>>3600119
I should add that in my opinion, organisms with bacterial-level organization and complexity are by far the most likely to find in any extra-terrestrial environment. Even given a planet *exactly* like Earth (as a thought experiment) I think that the vast majority of the time, life would remain at that level. It's my opinion as someone well-versed in biological sciences that the transition between prokaryotic and eukaryotic regimes of complexity was the single most dramatic and least likely in the history of life. I don't give good odds on a duplication, even in exactly similar circumstances. Though some people do not like to admit it (they're more comfortable with inevitability) there has been a great deal of contingency in the course taken by life on Earth.

[Anonymous No.3600313]

>>3600165
In spite of what I said about morphological convergence in >>3600119 I think biochemical divergence is to be expected. We don't know much at all about abiogenesis, but we can look at its products (the fundamental macromolecules of life) and see that while they exhibit remarkable properties in general, there is nothing all that special about them *in particular.* For instance, there are many sets of bases capable of Watson-Crick style base pairing. There is nothing overwhelmingly unique about the four (five, counting U/T separately) bases that form the basis of genetic information storage. Many synthetic analogue systems demonstrate similar properties. What you have is a subtle distinction: the *overall structure* is very special, but the *chemical details* are not unique.

The same story plays itself out when you consider the backbone. There is just nothing tremendously special about ribose or deoxyribose. Many other backbones have been synthesized, and while the catalytic properties and evolvability of these backbones has not been tested extensively, there's every indication that backbones based on peptide bonds, threose, etc. could have served instead.

[Anonymous No.3600316]

>>3600313
Those aren't even the clearest examples of things that might have been different. The most canonical example is the genetic code itself and the natural complement of amino acids for which it codes. The genetic code is "degenerate" meaning that there are redundant combinations that could have been allocated to additional amino-acids, but they aren't. There are some amino-acids that have fairly similar properties, so that it's easy to imagine that biology could theoretically have done without one or the other of several pairs. There are also potential analogues that could have taken the place of some natural amino acids. The number and precise identity of amino acids shows every mark of being something random that was just carried forward through the history of life. It's a diverse complement of them, sure. It's hardly a random collection: the coded amino-acids canvass a broad range of chemical properties. It just isn't a *unique* collection.

[Anonymous No.3600364]

There are so many kinds of organisms that could exists on worlds entirely different from ours. There could be sentient clouds of gas that manipulate objects with laser beams for all we know.

[Anonymous No.3600401]

Absolutely. Anyone who says otherwise, kindly draw me a picture of what you think aliens look like.

Evolution conforms to environment. Earths environment is the only one known to support evolution. It logically follows that we can assume they will look like us.

I am willing to bet the life of my first born child that our interplanetary observers are bipeds

[Anonymous No.3600415]

COULD THERE BE LIFE ON THE SUN?

MADE OF INVISIBLE DIAMONDS???

[Anonymous No.3600422]

>>3600415
WHY DIDN'T I THINK OF IT BEFORE

[Anonymous No.3600446]

>>3600364
Perhaps, but it's total terra incognita. We have seen no such life (not even one example) so there's just not much we can say.

>>3600401
Again, please look at the history of life on Earth. Generally, each habitat has been inhabited by creatures with a diverse range of morphology. There's just no reason at all to suppose that alien life would resemble present-day Earth life more than biospheres of the past. About these "observers," I won't believe in them without proof. All available evidence seems to indicate that intelligence is only favoured in a narrow range of circumstances. A hegemony of unintelligent but efficient predators seems quite sufficient to preclude the path thereto. Evolution isn't looking out to make intelligence at every opportunity.

[Anonymous No.3600458]

>>3600446
>There's just no reason at all to suppose that alien life would resemble present-day Earth life

> Say Aliens exist, what are the chances we've seen something similiar to them before?

[Anonymous No.3600478]

>>3600458
What's the matter, are you too chicken shit to quote my entire sentence? You have to take little bits out of context?

People like you make it futile to even try posting any nuanced viewpoint on /sci/. This isn't fucking CNN and we don't need your "word bites." Eat shit and die.

[Anonymous No.3600483]

If you mean alien life in general, then they are pretty plentiful in the form of bacteria; the simplest organic lifeforms known to man. However, when it comes to intelligent alien life, which most would define as possessing technology; that is anyone's guess. However, going by that definition the traits they would have the highest probability of possessing would be eyes that are fixed forward and hands with opposable thumbs (though the total number of digits wouldn't matter as long as they are more than three on each). This is because the technology we have now is descended from the tools our hunter-gatherer ancestors developed to help hunt more effectively, and so it wouldn't be that big a stretch to assume that any aliens that possess technology of any sort would be descended from hunter-gatherers like we are (which would also mean that Sagan is most likely wrong about aliens being inherently benevolent). That said, there is some scientific validity to the outward appearance of the Greys.

[Anonymous No.3600489]

>>3600478
Lay off the Red Bull, bro.

[Anonymous No.3600494]

>>3600446

Intelligence never became the primary criterion for selection until we became bipeds. It's a big deal to have the free hands.

[Anonymous No.3600505]

>>3600483
It would also be important to note that the total number of digits they have would also be the base they use for their day-to-day use numbering system. We use a base 10 numbering system because we have a total of ten digits on our hands. Likewise if aliens had a total of sixteen digits they would use hexidecimal.

[Anonymous No.3600516]

>>3600494
True, but we also nearly became extinct several times since we became bipeds. Our survival was tenuous in the utmost. Our kind skirted closer to the precipice of extinction that almost any other large animal.

There's a conceptual problem in taking an evolutionary strategy so marginal that it just *barely* worked and extrapolating it to extra-terrestrial organisms.

We were sucking it up for millions of years as evolutionary also-rans. That's not the hallmark of a path so successful that it *must* be emulated.

[Anonymous No.3600548]

>>3600489
Lay off the shitposting, bro.