Cool Life on Mars video

[Sinornithosaurus]

Thoughts?

[abzu93]

My understanding is that methane level readings on Mars are much lower than they expected, given a prior reading from another instrument. That indicates there probably isn't the plethora of bacterial life they were expecting. However, there are living organisms on earth that do not exude methane living under the surface, so there may be on Mars as well. I won't be holding my breath for plants or animals though.

There was and is liquid water, and that's something.

[ExpHP]

I used to often wonder myself about what kinds of completely different life forms could exist. And there's some pretty creative ideas in that video.

However, watching it now brings to mind a certain fascinating concept in biology known as convergent evolution. Multiple times in the history of the earth have entirely different species evolved similar features. Virtually every flying species ever has had wings, regardless of what they evolved from. And dolphins have fins, even though they are not fish. Basically, the pathways of evolution are, to an extent, natural and predictable; it isn't all due to chance.

Mars is a different environment from earth, and so we could certainly expect that life on Mars would be pretty different if it were to have existed. And yet, in the end, I don't imagine it would have been too different.

[Gunnerman21]

Yep, I often think of life on other worlds too. All planets have the same laws of physics, so plants and animals or whatever life is on the planet would possibly be creepily similar to earth life. We may even find homo-sapien-like creatures on other planets because we are a very versatile shape for advanced movement, like throwing spears or building huts.

[Sinornithosaurus]

We may even find homo-sapien-like creatures on other planets because we are a very versatile shape for advanced movement, like throwing spears or building huts.

No no no no no. Just no.

So what if a humanoid form is versatile? There are many other conceivable forms that are just as, if not more, versatile than the humanoid form.

I am sick and tired of humanoid aliens, these are entirely different worlds we're talking about, with different conditions and environments.

[abzu93]

We may even find homo-sapien-like creatures on other planets because we are a very versatile shape for advanced movement, like throwing spears or building huts.

I wouldn't expect that intelligent life would necessarily be housed in a primate-style body type. Just look at how many different body types we have just on our planet that are far more efficient at certain tasks than primates are. I can think of insects that could probably do a better job than primates at throwing spears or building huts.

If we found intelligent aliens or they found us, I don't think the resulting meeting would fair well for one, the other, or both. Just use review your BTW experience as a guide to how you think that might go down.

[eternal8phoenix]

We may even find homo-sapien-like creatures on other planets because we are a very versatile shape for advanced movement, like throwing spears or building huts.

I wouldn't expect that intelligent life would necessarily be housed in a primate-style body type. Just look at how many different body types we have just on our planet that are far more efficient at certain tasks than primates are. I can think of insects that could probably do a better job than primates at throwing spears or building huts.

If we found intelligent aliens or they found us, I don't think the resulting meeting would fair well for one, the other, or both. Just use review your BTW experience as a guide to how you think that might go down.

I seriously doubt the existence of sentient insectoid aliens. Intelligence requires a certain size of brain, and getting an exoskeleton that big would A) be so heavy as to crush the inhabitant of said exoskeleton at anything like earth gravity and B) even at low gravity the amount of energy required to move that big exoskeleton would be phenomenal. It's insides would have to be more mammalian or reptilian in structure....no way insect guts can power that kinda movement. And reptilian is only tentative, if the planet has a sufficiently high temperature.

The other issue is whether or not a planet with low enough gravity to support large exoskeletal creatures has enough gravity to maintain sufficient atmosphere so as to not choke said alien.

[Sinornithosaurus]

You know, aliens probably wouldn't be insectoid, or mammalian, or reptilian. They probably would evolve entirely different forms based on their enviroments

[eternal8phoenix]

I'm describing by approximates. They are likely to share some traits with earth creatures. So when I say insectiod I'm referring to exoskeletons, primitive or no internal organs, mammals: warm blooded, complex organs, live-births or reptilian: cold blooded, complex organs, egg laying.

They almost certainly would evolve differently based on environments, but I think you underestimate how much the environment varies on earth. We can see how live evolves under lower gravity....just hop on a submarine. Same for higher pressured atmospheres. For different atmospheric compositions look at life that's evolved to live around volcanoes or steam vents or even toxic waste outlets. Hell, we even have arsenic based life-forms as opposed to carbon. Earth is a massively diverse biosphere and it's reasonable to say that it's more than possible for life elsewhere to mimic features of creatures on this planet.

[ada221]

one thing i believe is that it will be very unlikely that an intelligent alien will be a herbivore, the energy required to power a sufficiently large brain for sentience1 must be taken from either meats(which have a high energy density) or a combination of meats and plants, else the time required to consume enough energy to power said brain will be more than the time in a day, let alone the time to actually use said sentience. Also, non herbivores are usually predatory hunters2, being a hunter means that you must always be one step ahead of your prey and therefore develop a higher brain capacity.

1: unless it is some type of hive mind race where individuals need less brain power but the aggregate species is intelligent (I.E. buggers from Enders Game minus the queen, or the Grik from Destroyermen minus the celestial mother)

2: or possibly scavengers, needing to develop brainpower to avoid (or cooperate with) predators that kill whatever they scavenge

A way around this would be if on this planet, edible plant life existed with a super high energy density and there were conditions that required a plant eating species to be "smarter than the average bear"

[abzu93]

I seriously doubt the existence of sentient insectoid aliens. Intelligence requires a certain size of brain, [-snip-]

There is absolutely no reason why this should be. There are mammals on earth with extremely large brains (18lbs). If you are just going by brain-to-body mass then again it's certainly not humans that lead this category either.

But lets throw out the data and say you are right. There isn't any reason an organism could not evolve a cavity large enough to house an intelligent brain. The incredible thing about life is it is extremely adaptable enough to fold itself into unexpected shapes, sizes, and places, on this planet over the course of the three billion years of the fossil record.

Anyway, it's all hypothesis until we actually come across something.

[eternal8phoenix]

There is absolutely no reason why this should be. There are mammals on earth with extremely large brains (18lbs). If you are just going by brain-to-body mass then again it's certainly not humans that lead this category either.

But lets throw out the data and say you are right. There isn't any reason an organism could not evolve a cavity large enough to house an intelligent brain. The incredible thing about life is it is extremely adaptable enough to fold itself into unexpected shapes, sizes, and places, on this planet over the course of the three billion years of the fossil record.

Anyway, it's all hypothesis until we actually come across something.

Brain-body mass ratios are indicative of more intelligent species, in general. Anything over a certain threshold anyway. I am aware we don't lead the pack though. :P

And it wasn't about the cavity. It was about energy usage. Brains are incredibly resource draining, and the more complex, the more they drain. Exoskeletons are heavy, relative to endoskeletons, hence why there aren't many large exoskeletal creatures on earth . They use significantly more energy on stuff like moving and breathing which can't be used on the brain.

But like you said....all speculation. I'd quite frankly love to be wrong, if only because it shows that there is so much more life is capable of, and that we have so much more to learn. Like how to dissect a giant cockroach. :P