Questions tagged [biology]

For questions about living things. Does not exclude aliens, but additional information is usually necessary (consider using "xenobiology" instead).

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22 votes
6 answers
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Could a species benefit from intercourse with another species with no DNA compatibility?

After reading the question on inbreeding (Could fictional species benefit from limited inbreeding?), I started to wonder if there could be any reasons why an species (intelligent or otherwise) would ...
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5 votes
2 answers
313 views

Gas Giant with Small Moons within the Gas? [duplicate]

Suppose a gas giant is incredibly large with a super dense, solid core that hold the gas around it like an atmosphere. Would small moons be able to exist within the gas, assuming the gas has little ...
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23 votes
6 answers
3k views

Living Planet Possible?

Although a question about how large a living thing could be has been asked and answered, would a being such as Mogo from DC's Green Lantern series be possible? Mogo is the size of Earth roughly can ...
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14 votes
2 answers
1k views

What effect would three moons have on ocean/landscape formation?

I'm building an alien world for a game mod, and want to avoid any blatant mistakes from a world-building perspective. The world has three moons visible in the night sky - two on one side near each ...
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10 votes
2 answers
871 views

Varying Gravity

Suppose a very large planet orbited a star or other spacial body in an oval shaped path, similar to Earth's but closer to induce a varying gravity during orbit. The planet has a large gravity well ...
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16 votes
6 answers
2k views

Could fictional species benefit from limited inbreeding?

There are quite a few known drawbacks to incest. However, incest can be helpful when trying to help a desired trait spread. Incest does happen in nature to some degree but it's not exactly actively ...
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25 votes
9 answers
4k views

How advanced or effective weapons can be created from mostly animal body parts?

I have a race of carnivorous mammals living in a very resource-poor environment. Due to a mixture of lack of resources (no metal, no wood or tough stems, etc) and cultural taboos, they are only ...
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32 votes
5 answers
11k views

Why aren't animals photosynthetic?

Why aren't animals photosynthetic on earth? And what would make it plausible for them to evolve to be?
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25 votes
4 answers
6k views

What minimal radius is needed for rotation to simulate gravitation without adverse effects on humans?

A quite common idea to provide "gravitation" in space stations is to make them rotate, so the centrifugal force gives an effective gravitation. A possible design is a ring-shaped space station. Now ...
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27 votes
7 answers
7k views

Could life form in outer space?

All life we know of to date (presumably) formed on a rocky planet (more precisely: earth). Fiction has been written about life in more exotic locations. Though as far as I know, these lifeforms were ...
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  • 5,535
10 votes
6 answers
5k views

What would happen to a planet that was electrically charged?

If a planet had such a large imbalance of protons and electrons that it possessed a net negative or positive charge what would happen to it and its solar system? First, could it be stable, or would ...
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18 votes
4 answers
596 views

Could inter-individual communication be based on DNA transfer?

There is this idea that we find in a few books, mainly The Swarm by Frank Schätzing and in the Ender Saga by Orson Scott Card, that some species could communicate via DNA exchange. Technically, yes ...
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8 votes
8 answers
519 views

Is it possible for a world-wide plague to start off as seemingly different diseases?

In the case of a world-wide plague epidemic that'll trigger the near extinction of humanity, is it possible that a virus/disease has inconsistent symptoms so that people aren't aware that it's really ...
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7 votes
3 answers
480 views

Maximum Earth population given biological shrinking

I want to create a world set on our Earth but with humans shrunk down as much as possible to allow a huge population. As the population increases they genetically modify their bodies to be as small ...
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  • 6,033
26 votes
8 answers
4k views

Can an atmosphere englobe a planetary ring?

Would it be possible for the atmosphere of a planet to reach beyond its planetary ring so that earth-like biology could develop on some of the asteroids there? This question is mainly about whether ...
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14 votes
3 answers
580 views

What would be the effect on life/civilisations if the length of a year was longer or shorter?

If you want to have a smaller star but you also want to keep your planet in the habitable zone, you need to put the planet closer to the star. This means shorter years. It is also possible to have a ...
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25 votes
3 answers
2k views

Assistance to fight off a silicon-based lifeform

I am a survivor of the United Nations Space Corp's 2nd Exploration Fleet. On our travel to the distant Epsilon Canares system, our scouts encountered a strange lifeform. We call them 'shapeshifters'. ...
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6 votes
1 answer
284 views

Biology of humanlike species within Buddhist and Judeo-Christian Realms [closed]

I have a world that I largely have figured out in a big picture sort of way. It's sort of a Buddhist realms style "multiverse" with multiple realms encompassing the true universe. In this multiverse ...
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34 votes
5 answers
37k views

Is it possible to genetically modify a being after birth?

In many stories we hear about people whose genetic structure is modified after they're born (Spider-man, The Fantastic 4 and practically any other superhero you care to mention). However current ...
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14 votes
7 answers
2k views

What is the likelihood that inhabitants of an alien planet similar to Earth geologically would have races?

First off, let's get definitions out of the way: A "race" here is defined as stable, heritable, phenotypic, clearly visual distinction between large demographic groups living in different geographic ...
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  • 4,632
12 votes
3 answers
848 views

Microbe transforming humans to plants

Note: This question assumes an earth-like biology. Could a microbe (probably virus) be created that transformed humans into plants? What I mean by this is that the microbe would take human cells, and ...
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3 votes
4 answers
235 views

Night and light in the reign of the lizardmen

So I'm writing a story on a population of lizardmen who have subdued all the human population. Since lizards spend lots of their time soaking in the sun, I'm not sure how should I go for the night-...
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20 votes
5 answers
4k views

Is it possible for complex life to evolve on planets without oxygen?

*By complex life, I mean something more complex than microorganisms. Something closer to what we have on Earth. Similar to this question: Is it possible for life to evolve on planets without water? ...
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18 votes
6 answers
3k views

Is it possible for life to evolve on planets without water?

*By life, I mean something more complex than microorganisms. Something closer to what we have on Earth. similar to this question: Is it possible for complex life to evolve on planets without oxygen? ...
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-1 votes
1 answer
422 views

How do we know that our bodies contain stardust? [closed]

How do we know we are made of stardust? As our cells divide, are our atoms repurposed from existing materials or spontaneously generated? Do we consume materials after we are born that contain ...
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59 votes
12 answers
17k views

Is a man-eating plant realistic?

Carnivorous plants live in nutrient-poor, highly lit habitats, such as bogs or rocks. For example Earth's biggest carnivorous plant, Nepenthes rajah, lives on mountain-tops with high concentration of ...
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23 votes
3 answers
9k views

What is the maximum size of a flying creature?

Giant winged beasts such as the Roc and the western dragon feature strongly in mythology. Is there a maximum size on a biological winged flying creature? How would an atmosphere different from Earth'...
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34 votes
8 answers
5k views

What environment would make leaves light blue?

What environmental effects (if any) would ever cause blue to be a colour that a plant would choose as an evolutionary advantage? Bonus: I'm looking for light blue plants as a preference. EDIT: ...
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  • 3,144
9 votes
2 answers
1k views

Life on an Earth-like planet with solid core?

How big a difference does the Earth's liquid outer core and mantle make for the evolution of complex life? If all of Earth's parameters would be the same, but it had a solid interior just like Mars, ...
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53 votes
18 answers
13k views

Is it possible for a species to have more than two sexes?

Every species I'm aware of on earth has two sexes (with the possible exception of species which change their sexes to allow self fertilization). Is it possible for a species to evolve which could ...
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98 votes
14 answers
10k views

Is there a scientific explanation as to why aliens should look similar to us?

In almost all science-fiction stories that include alien races, said aliens are similar to humans in many ways: bipedal (and often humanoid), communicate with sounds coming out of a mouth, orient in ...
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39 votes
2 answers
4k views

What would be the evolutionary advantage for plants to be bioluminescent?

As fas as I know, there isn't a single plant on Earth that (naturally) produces any sort of luminescence. But it is seen in science-fiction worlds, especially Avatar. From an evolutionary point of ...
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19 votes
2 answers
1k views

Food sources for an undergound city

Lets assume a city exists underground, either in natural caves or synthetic tunnels. Are there any food sources underground, and what kind of population can they support?
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19 votes
1 answer
4k views

How would having a prehensile tail change society? [closed]

This answer made me wonder, how would our society be different if humans had tails? Of course, tails come in all sorts and sizes, so let's say we had a monkey type tail. One you could wrap around a ...
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  • 1,077
41 votes
12 answers
5k views

How would society be different in a sentient species that does not care for its young?

A lot of species on earth do not care for their offspring; they spawn thousands of eggs, that hatch into larvae, and then grow up towards full size. If a hypothetical species was sentient in the ...
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49 votes
12 answers
5k views

Natural Projectile Weapons

I'm not aware of any animals which have evolved projectile weapons that they fire. There are a number that spit venom but none that even throw rocks, let alone using projectiles. On the other hand ...
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16 votes
2 answers
2k views

What effect would a radical gravity change have on plants and fungus?

In relation to this question, what would plants do if they were taken from their environment to another gravity level, in particular zero g. For example would the daisy manage to grow higher ...
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19 votes
5 answers
6k views

What is the limiting factor for a plant's growth?

This question is about big trees that can contain an entire city. So generally speaking: What limits a plant's size, anything from a tree to a flowering plant? What environment needs to exist for ...
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30 votes
7 answers
3k views

Are invisible creatures theoretically possible?

Would it be possible for a corporeal alien with a solid physical body (it must be able to touch and interact with the world) to exist but remain invisible to humans? My understanding of optics is ...
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  • 687
22 votes
4 answers
2k views

City in a hollow tree

As a tree grows new layers are added each year so that the trunk expands in radius. The living part of the tree is a relatively thin layer on the outside just beneath the bark, and the wood further ...
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  • 6,033
27 votes
6 answers
11k views

Are dragons cold or warm blooded?

My world is science-based with an earth-like biology. The dragons fly when they're young and then grow too heavy and can only glide if at all. They breathe fire by expelling gas and igniting it. They ...
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31 votes
6 answers
8k views

Does living without access to sunlight for extended periods have known physical or psychological effects on humans?

Humans (even programmers :-) ) are used to having some access to natural light, but in a colony in space, on the dark side of a tidally-locked planet, or underground (for example) this won't happen. ...
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13 votes
1 answer
329 views

Are infections necessary for human colonisation?

If a human colony is set up on another planet or moon, or in an orbiting habitat, most of the infectious diseases from Earth would not be present in the small initial population. Careful screening ...
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29 votes
5 answers
2k views

How critical is it for life that a planet remains within the habitable zone at all times?

Important note: The orbits in the diagram are elliptical. They have low eccentricity so they appear to be off centre circles but they really are ellipses with the star at a focus. The habitable ...
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  • 4,709
24 votes
5 answers
6k views

What would a habitable moon most probably look like?

We have a pretty good idea of what attributes a planet would need to sustain life and one can imagine how life might develop on a planet, even in difficult environments. I find it extremely difficult ...
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  • 341
52 votes
4 answers
6k views

What would a planet spinning fast enough to allow geostationary orbit near the surface look like?

From an answer to a previous question of mine: A planet spinning fast enough to allow geostationary orbit near the surface would result in odd side effects. Any object at rest on the equator would ...
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57 votes
3 answers
18k views

Is there a maximum size an ocean bound creature could grow to?

Assuming the ocean is deep enough and not overcrowded is there any upper limits to the size a "sea monster" can grow? On land creatures are limited by gravity, they have to be able to generate the ...
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  • 18.1k
74 votes
4 answers
8k views

Can you simply scale up animals?

There have been a number of questions focusing on mythical creatures where the logical approach to answering has been to scale up an existing animal. For example dragon's wings can be extrapolated ...
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194 votes
18 answers
79k views

How could dragons be explained without magic?

Dragons are a grand classic of fantasy. For this question, let's assume we're talking about the following stereotype: hatches from an ostrich-sized egg and can grow to mountain size if nothing limits ...
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  • 12.1k
63 votes
15 answers
39k views

Would the human body support living on planets with a greater gravity than Earth?

I once read a novel about a prison-planet which was chosen to make the prisoners suffer. One of the different "tortures" was a gravity three times higher than that on Earth. Would the human body ...
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