Questions tagged [xenobiology]
For questions related to the biology of extra-terrestrial organisms. This tag implies the use of the science-fiction tag. Use the science-based or hard-science tags to impose greater scientific restrictions (see warning in tag wiki). The goal of this tag is to answer the question using known science.
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Is this alternative quadrupedal limb arrangement (two side limbs, one forelimb, and one hindlimb) evolutionarily plausible?
Four extremities below the body are the fewest needed to maintain a rectangular platform on any surface while still being decently stable. When they are arranged at the corners of the body like table ...
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Could life on my planet use hydrocarbons and tholins as the base of the food chain instead of plants?
On Earth the basis of nearly all multicellular life in the biosphere is photosynthesis where light is captured and converted into chemical energy. Said energy is then used by other organisms.
However ...
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A Review of my Diploid-Triploid Sex Determination System
I am designing a sentient species with a significantly skewed sex ratio towards the males, something like 3 or 4 males per female. I have been trying to think of a explanation that would justify this ...
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What conditions on an Earthlike planet would allow for a massive, Pando-esque forest that’s a single organism?
I’m assuming that you probably know of everyone’s best friend Pando, the aspen system that spans over a hundred acres in Utah while still being one single tree? I’m creating a science-fiction series ...
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Wing dimensions in four winged Megafauna
Basilocetids (working name) are flying animals that have grown in size to eat more things, specifically reaching nearly 7 meters in length (important for ecological reasons I won’t go into). Their ...
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Pupil shape for a condor-like mega-scavenger
The Savannah Wyvern is a gigantic megafauna found in the deserts and savannah of the world I'm trying to create. The wyvern is similar to a vulture or condor, but expanded to gigantic proportions, the ...
user135063
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What kind of drinks would a strictly carnivorous alien consume?
I'm working on something where some sapient species aren't capable of digesting plant or vegetable matter. It has occurred to me that for these beings, plant-based drink like beer or wine probably ...
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Fire in a Hydrogen Atmosphere
In my world (described further in my question How Would Wind be Different in a Hydrogen Atmosphere) plants build biomass by this reaction (where $hv$ is light energy):
$CH_{4} + H_{2}O + hv \to CH_{2}...
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Organic monomers and macro-molecules for silicon-based life?
While silicon based life form are entirely speculative, and it's still up for debate if it even could exist, much less whether it does, I wanted to ask if there has been any informed speculation about ...
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Ideal bilateral pentapod bodyplan [closed]
I've been breaking my head over how I want to undertake the basal bodyplan on my hard science world. I've settled on 5 legs, but don't exactly know which would be the most stable, or realistic.
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Ways for a Planet to Produce More Silicic Acid
If you've seen my previous posts then you might know that my planet is a super earth orbiting a K3V star at 1.6 AU. It has 2g gravity and typical rocky planet composition with a hydrogen (90%) ...
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How fast could a small squid-like jet propelled animal go? [closed]
I’m working on a speculative evolution project on a small moon of a gas giant. This moon is an ocean world with oceans on average 17 kilometers deep. It’s has about 17% earths gravity. It is covered ...
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My crab-like creature underneath a 5 km thick ice: Please review my idea [closed]
Please review my creature
This is a member of the phylum xivapoda (14 legged in Latin) in this world and is very crab-like, with the exception that it is up to 10 meters tall measured from base of leg ...
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What factors could lead a sessile organism to develop sapience?
As said above, my question is simple: what factors could lead a barnacle-like sessile organism to develop intelligence and sapience? They inhabit an earth like planet, and are filter feeders living on ...
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How would a plant disconnected from the ground get nitrogen?
I’m working on a rogue planet with a Europa-like moon with life beneath the ice. I also want a plant that, instead of being connected to the ground, would float through the currents. To clarify, the ...
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Can other sources of energy be used to fuel photosynthesis other than sunlight?
I’m working on a rogue moon that when life evolved it was around a star. Currently it has an ice shell kilometers thick and a deep ocean of liquid water beneath. I already know that chemosynthesis ...
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How, anatomically, can an alien species have pointed digits (without claws or nails)?
One of the early-stage alien species designs floating around in my head (like some other fictional species) has pointed digits.
"Okay," I hear you say, "what needs answering about a ...
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How small can a human-like eye be?
Ultimately, resolution is constrained by diffraction limits, so using smaller wavelengths of light gets you more resolution for a given eye size, and a smaller eye ends up with a worse diffractive ...
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How would a lack of sexual selection affect an intelligent species' development? [closed]
In this alien society, reproduction occurs via external fertilization, in a relatively impersonal way. Eggs are left at designated chambers or nests, and others with the ability to fertilize them can ...
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Why would an intelligent species take over a century to mature?
This alien species lives for a few centuries, but takes around 100-150 years to mature from a simpler infantile/juvenile form to young adulthood. The species is very advanced and has been for a while—...
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How would the eyes of this species evolve if only exposed to mercury-vapor lamps?
Mercury-vapor lamps
Their light is relatively harsh, both just from a visual standpoint, but also from the fact that they emit a bit of UV radiation.
On an off-world colony settled by my ET species ...
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Unidirectional breathing with a third nostril?
I'm writing a world with a humanoid mammalian race in a low-oxygen world. For a whole lot of reasons (evolved from an alien version of a sugar glider bat thing, hemocyanin Blood, classic folklore), I ...
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Can a mercurian mass exomoon and or planet support earth like life?
I am interested in the possibility of low mass habitable planets. My major question is what conditions would need to be in place for a roughly mercurian mass moon or planet to be habitable. My ...
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Evolution of Efficient Lungs for Low-Oxygen Planet compatible with Hemocyanin Blood
As stated in the title, I am writing in a world with low oxygen (10% ish of atmosphere, with a slightly larger atmospheric pressure than Earth; these figures are fluid and can change). I want a human-...
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Does an ancient alien race that created most sentient life make sense?
In my alien universe, there are legends of an ancient species called The Archonians, who were incredibly advanced genetic engineers, harnessing an energy source that exists outside of the Multiverse. ...
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