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Questions tagged [biology]

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

9
votes
2answers
847 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 ...
16
votes
6answers
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 ...
20
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7answers
3k 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 ...
29
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5answers
7k 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?
22
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3answers
3k views

What minimal radius is needed for rotation to simulate gravitation without averse 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 ...
25
votes
7answers
5k 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 ...
8
votes
6answers
4k 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 ...
17
votes
4answers
514 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 ...
8
votes
8answers
393 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 ...
6
votes
3answers
422 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 ...
25
votes
8answers
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 ...
12
votes
3answers
421 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 ...
25
votes
3answers
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'. ...
6
votes
1answer
235 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 ...
35
votes
5answers
30k 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 ...
13
votes
7answers
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 ...
11
votes
3answers
738 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 ...
3
votes
4answers
196 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-...
17
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5answers
3k 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? ...
17
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6answers
2k 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? ...
-1
votes
1answer
403 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 ...
54
votes
11answers
15k 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 ...
18
votes
3answers
6k 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'...
33
votes
8answers
4k 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: ...
8
votes
2answers
981 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, ...
47
votes
18answers
10k 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 ...
81
votes
14answers
8k 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 ...
35
votes
2answers
3k 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 ...
15
votes
2answers
781 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?
18
votes
1answer
3k 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 ...
33
votes
12answers
4k 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 ...
46
votes
13answers
4k 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 ...
12
votes
2answers
1k 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 ...
16
votes
5answers
4k 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 ...
27
votes
6answers
2k 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 ...
20
votes
4answers
1k 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 ...
24
votes
6answers
7k 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 ...
26
votes
5answers
6k 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 on the dark side of a moon or underground (for example) this won't happen. Are there known (documented) ...
11
votes
1answer
288 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 ...
24
votes
5answers
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 ...
22
votes
5answers
4k 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 ...
46
votes
3answers
5k 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 ...
45
votes
3answers
12k 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 ...
61
votes
4answers
6k 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 ...
166
votes
18answers
51k 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 ...
55
votes
14answers
29k 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 ...
39
votes
10answers
7k views

What effects would a change in the nature of human sexuality have on society and infrastructure

Consider a group of humans at a bronze-age to early iron-age technological level colonizing a new earthlike planet. There is just one difference - there exists on the planet something which changes ...
24
votes
8answers
2k views

What could cause rock formations (small stones, boulders, islands…) to levitate?

You see this in quite a bunch of movies / books (think avatar). What could be a reasoned physical explanation of such phenomenon? Would this explanation impact other things on a planet? Like most ...
-2
votes
2answers
304 views

Is it reasonable/realistic for a 6 year old to not be very different in 6 years? [closed]

above in a image of Vivio Takamachi with her Godmother Fate on the left and Adoptive Mother Nanoha to the right. Given how Einhald is not in the image it would be set during Magical Girl Lyrical ...
26
votes
2answers
461 views

Physical speed of insectoid lifeforms

Would humanoid sized insectoid lifeforms be relatively slow considering that their exoskeleton would have to be rather heavy since it takes more 'armor' to get the same relative protection? Generally ...