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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47
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3answers
6k views

How early was the Earth liveable for today's humans?

Say you were to drop a (bunch of) human(s) at some past era of our Earth. I'm assuming they might encounter a few problems such as the composition of the air not being breathable, the water being too ...
17
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7answers
3k views

How would long-term exposure to artificial gravity (as generated by a Stanford torus) affect human evolution?

A space colony that resembles the design of a Stanford torus generates artificial gravity by centripetal force. Discussions about benefits of such fake gravity can be easily found: no more constant ...
5
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1answer
608 views

What would be the short-term and long-term effects of an increase in the strength of gravity on humans?

I heard that some scientists placed chickens under 2.5g for 6 months, and they survived. A normal human would black out at 5g. A trained astronaut could take up to 8g before blacking out. 20g would ...
18
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12answers
9k views

Could a space-dwelling creature survive solely off of sunlight?

On Earth, photosynthetic organisms require additional nutrients to survive; in addition to "feeding" off of sunlight, plants respire and absorb water from the ground in order to grow. However, the ...
30
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16answers
4k views

How could a human-descended race appear to be all-female?

A group of behaviorally modern humans was cut off from the rest of the earth-like planet. At the time of the separation, humankind had reached a technology level including cattle ranches, brass, ...
8
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5answers
1k views

Effects on the visual systems of humans when temporarily having several stars illuminating the living space

A modern day Earth nation is at war with another. That other nation is extremely advanced but they are also pacifists. Instead of killing peoples their gun rounds and shells have the effect of ...
12
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5answers
3k views

Is Superman a peeping Tom? or Would x-ray vision be biologically reasonable?

Real x-ray vision, the ability to (at least) detect X-rays as a 'visible' light (or any other detection system) seems it would be very problematic. First X-Rays are a high energy electromagnetic ...
30
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5answers
4k views

Dietary Requirements of Giant Spiders

Giant Spiders are a traditional element of fantasy worlds. They prey upon most human's primal fears, and are easy to make as evil as possible. (Note: Not to scale) But are they actually plausible? ...
4
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2answers
2k views

Functional change of genital organs

Let's see if I can explain my thoughts accurately with an example. Imagine that a mad scientist decides to kidnap a few men and women and decides, just for fun, to switch their sexual organs, but not ...
9
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3answers
701 views

High Voltage Nervous System

Would it be possible for a creature to have a nervous system working at 250 volts? What kind of physiology would it need to sustain that? Could you use that creature as a power source, to power a ...
23
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7answers
31k views

How would the human body develop under a different gravity?

What would be the effects of high or low gravity on human body development? How would the human body develop under a different gravity? Many science fiction stories explore the idea that people from ...
10
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4answers
513 views

Can one humanoid species evolve to live at an altitude where another, similar species could not survive?

It seems that people who live at very high altitudes have demonstrably "thicker" blood, highly concentrated with red blood cells to overcome the low concentration of oxygen in the air. Moving between ...
7
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2answers
427 views

In life, what might substitute for phosphorus, if only trace amounts of phosphorus is available in the environment?

What sort of xenobiochemistry would support information-carrying macromolecules like DNA if only trace amounts of phosphorus were present on an alien planet? Since the phosphoribosyl backbone of DNA ...
11
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2answers
2k views

Could Mars-colonized humans survive a return to Earth?

Mars' gravity is 38% of that of Earth's. Supposing a human born and raised on a Mars colony traveled to earth later in their life, would they be able to survive the increased gravity? ...
11
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5answers
1k views

Could higher land-based life exist on a planet with a pressure of about 1 MPa?

This is somewhat of a follow-up question to my ammonia-based world question. I've found out that the melting point of ammonia is at 25°C at a pressure of about 1 MPa (about 10 times the atmospheric ...
18
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9answers
3k views

What would be a realistic, competent response from the rest of the world if Britain were wiped out by a zombie virus?

I am referring to the situation described at the start of the movie 28 Weeks Later, where Britain had been wiped out by a zombie virus, but the rest of the world was (seemingly) fine. What would be a ...
14
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3answers
1k views

Could a cold planet (tundra) develop and maintain a breathable atmosphere for humans?

Initial situation: I have cold planet with an average temperature below the freezing point. There is a magnetic field. The planet is almost as big as Earth and can have an atmosphere. The planet ...
36
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19answers
13k views

How long would it take for a new intelligent species to evolve if humans disappeared?

If all humans (but no other species) just suddenly disappeared, leaving all of their structures standing, how long would it take for an intelligent species as dominant as the humans to evolve? Would ...
11
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2answers
3k views

Can anything survive by eating rocks and other ground minerals?

Are there bacteria or other types of lifeforms that feed on rocks and other ground minerals? And if there aren't, is it technically possible? It can eat other things but the majority of its diet ...
12
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6answers
752 views

An enviroment where a bird-like creature can survive on passive feeding

The question about a diet of dust brought up a few creatures that survive on dust, however they were all insect sized or smaller. This got me thinking about the Blue Whale which survive on a diet of ...
4
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4answers
417 views

Could life survive on a diet of dust?

Could life survive on a diet of dust or some other substance that is both abundant and that we don't place any value on?
3
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3answers
2k views

What species, if any, would survive this kind of apocalypse, and what would global environment be like?

So, this is going to be kind of a tricky question to answer, because the setting is a science fantasy world, in the sense that, on the surface at least, it looks like our reality and it seems like the ...
8
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5answers
1k views

What would be the effects of the common house cat rapidly acquiring flight ability?

Assuming planet Earth, with considerable amounts of pets per household (96 million cats in the US alone), what would be the social and ecological consequences of all domestic cats acquiring flight ...
16
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8answers
3k views

What are some ways to explain how a shapeshifter retains his/her mental capacity?

Magic conveniently "explains away" many things associated with shapeshifting, but in the course of some of my fiction writing, I endeavor to include some slightly more plausible explanations when ...
9
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5answers
4k views

Human/alien breeding generating an alien

I hope my question isn't too vague or broad. It's a follow-up to this one. So, we have a human (genetically modified in order to support life on another place, from previous question) on an alien ...
2
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3answers
217 views

What social structure would be developed by an intelligent species with distinct functional physical differences?

Racism has been a defining trait in how human civilizations have interacted and developed in regard to each other. It, however, is founded on differences which separate us visibly but not ...
6
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4answers
270 views

Could life be sustained purely from a gas?

Could life be sustained only by a gas? Humans need food, water and air but can a ET or Alien could just live off gas.
41
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16answers
7k views

What could cause an avian species to become intelligent?

There have been a few questions about an intelligent avian species lately and they have gotten me thinking. It seems to me that it would be hard for an avian species to evolve to be more intelligent ...
8
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3answers
1k views

Evolution without the reflex arc

How would evolution have changed without the "reflex arc", if all reflexes had to go through the brain instead of the spinal cord? Would intelligent species be able to evolve?
6
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2answers
778 views

What would change in a dominant/predatory animal given two heads?

Take any well-known aggressive/dominant/predatory animal - wolves, big cats, bears, dragons, etc. Now say this animal were to have two heads, each equal in all capacities. What would realistically ...
33
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4answers
63k views

How big would a pair of wings need to be to allow an adult human to fly in a given environment?

Lets indulge in a bit of Mad Science, here. Assuming the world described here: Making the Enterprise Fly (60% of earth's gravity, 50% denser atmosphere) what is the wingspan needed to allow an ...
42
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11answers
11k views

What happens to a human who receives more information than the brain can process?

Often in films and television shows when a person's brain is 'injected' with more information than it can handle, they suffer from immense pain. What would actually happen if you did supply a human ...
19
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2answers
1k views

Life on a planet with multiple gas layers

Could a terrestrial planet have a stable set of layers of atmospheres, and could different lifeforms evolve within those different layers? This question is inspired by the diversity found on Earth. ...
17
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2answers
4k views

Is metal-based, or other non-carbon-based, life realistic?

One science fiction short story I read (I don't remember the title or author, sorry!) featured some small creatures (unnamed) that were formed from metal, with the argument that "just like life ...
8
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3answers
451 views

Generating a Magnetic Field Biologically

I was answering this question about how a living planet-organism could be possible, and realized I didn't know how such a planet-organism could produce a magnetic field. I postulated that it could ...
8
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4answers
616 views

Bioluminescent Organisms that use Light to Communicate?

Suppose such an organism had evolved from using sound like most life we know to use different intensities, wave lengths, and hues of light to communicate. This is assuming that these creatures are as ...
22
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6answers
4k views

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 ...
5
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2answers
295 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 ...
22
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6answers
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 ...
13
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1answer
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 ...
9
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2answers
850 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
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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 ...
25
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9answers
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 ...
32
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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?
24
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4answers
4k 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
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7answers
6k 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 ...
9
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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
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4answers
538 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
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8answers
428 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
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3answers
437 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 ...