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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).

167
votes
18answers
53k 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 ...
153
votes
26answers
29k views

Can a substance be more lethal in smaller doses?

Yes, I realize this question is a bit ridiculous, and there are no cases of it in reality (that I can find), but with a bit of truth twisting, could it theoretically be possible? In my fantasy world ...
127
votes
11answers
23k views

Everything alive in the world dies this instant. Without bacteria to decompose anything, what happens to the remains? What does this look like?

So when I say everything, I mean everything. Humans, animals, plants, fungi, bacteria, all dead. If the bacteria and other detritovores and decomposers can't decompose anything since they themselves ...
99
votes
19answers
14k views

What mechanism can prevent super-healing heroes from accidentally budding?

We’re all familiar with the heroes that can’t die. Honey-badger (with the claws and the angry voice), Dreadpeel, that girl with the weird cheerleading obsession... Basically they all have the same ...
90
votes
19answers
27k views

Why would vampires be incapable of entering a non-vampire human’s house uninvited?

I'm looking for a scientific explanation as to why vampires would be incapable of entering a human's house uninvited. There have been many terrific scientific explanations for some of the most ...
85
votes
13answers
22k views

Lembas bread (2000 Calories per bite)

In the lord of rings the elves invented an incredibly nutritious bread/biscuit, as Legolas clearly says only a small bite is just enough to satisfy the needs of an adult man for 1 day. An adult ...
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 ...
77
votes
17answers
17k views

Would a 'World Tree' be feasible in real life?

A livescience.com article claims that trees can reach a theoretical height of 400 to 426 feet (122 to 130m). This is due to the tree being unable to carry water up to the top at that certain point due ...
65
votes
19answers
15k views

How would an astronaut conclude he's on Earth, but 600 million years in the future?

Say we have a group of space travelers who have been frozen inside a sleeper ship for an enormous amount of time that left when Earth was recognizable. When they thaw out and reach their destination, ...
61
votes
22answers
13k views

How can waste from the body be removed without being expelled from the anus?

Humans are savage creatures. This is indicative in the way they get rid of bodily waste. Squatting over a glorified hole in the ground or aiming their spear tip toward same hole and hoping for success ...
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 ...
59
votes
15answers
11k views

Is Cancer Biologically Universal?

Cancer works by making cells split and reproduce at an accelerated rate, slowly and painfully killing the afflicted. Its true weapon lies in its ability to surpass the immunity system. As far as I ...
59
votes
9answers
7k views

How does the Booze-Rat fuel its defensive mechanism?

Of all the creatures in Hatjörn's dominion, there is none as peculiar as the Murinae Spirita, the mean booze-rat. A vermin so resilient that has developed the most wondrous means of defence and thus ...
57
votes
10answers
19k views

A Bird that Never Touches Ground

Birds, as we currently know them, build nests and lay eggs on the ground. People and things with sharp teeth live on the ground. There are also things with claws and beaks up in the air, but fewer. I ...
56
votes
18answers
10k views

How do you power all the nanobots?

We have successfully put 37 trillion nanobots the size of a red blood cell into the experimental group test subjects' willing participants' bloodstream, but without a power source, the nanobots clot ...
56
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 ...
54
votes
10answers
7k views

What could cause sugary rain?

In a world very similar to ours, rain has a high concentration of simple carbohydrates in it, enough to sustain life on the surface. After some rainfall, this sugary rainwater is left behind and some ...
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 ...
53
votes
25answers
7k views

Lifeform - resistant to gunfire but vulnerable to melee

Is there a plausible makeup for a lifeform which is highly resistant to even very advanced firearms (or any ranged weaponry for that matter), but can be injured more readily (albeit still a major feat)...
53
votes
12answers
14k views

What kind of natural armor would stop bullets?

It should not resist 50 cal bullets, but an armor which could protect a creature from the US standard issue rifle, for example. Here are a couple of things the armor needs to do: Protect the creature ...
53
votes
8answers
9k views

Does a grenade kill you the same way a gun does?

Disclaimer This seems a particularly stupid question, but the more I think about it, the less trivial I find it. Worldbuilding possess the most appropriate tags. It does not fit in physics-network ...
51
votes
23answers
11k views

What possible scientific reasons could there be for a vampire to only be killable via wooden stake to the heart?

This excludes metal stakes, knives etc. to the heart, it's not the bleeding out that's the issue. Just for some reason, a wooden stake to the heart ends a vampire. Why? Assume the type of vampire ...
50
votes
5answers
6k views

Anatomically correct sharknado shark

Raining animals is a rare meteorological phenomenon in which flightless animals fall from the sky. Such occurrences have been reported in many countries throughout history. One hypothesis is that ...
50
votes
6answers
6k views

Could Cobalt bind to nitrogen the same way iron would to oxygen in an alien respiratory system?

I'm making this whole other alien world and I made it an ammonia world, so there is a lot of nitrogen in the atmosphere. Would nitrogen be a good gas to breathe in an ammonia world and would Cobalt be ...
50
votes
14answers
6k views

Would charging unicorns survive the impact with a line of infantry?

The unicorns would be used to charge a line of infantry with their horn. They are as big as a horse and the horn is similar to this image: The infantry is a standard medieval army made mostly of ...
49
votes
28answers
10k views

Poison which constantly needs to be treated by antidote to not get killed

Inspired by Frank Herbert's Dune: Action Joe is kept prisoner in Doctor Evil's prison. Doctor Evil knows that Joe's escape is inevitable. So he decides to introduce poison to Joe's body. Joe gets his ...
49
votes
9answers
10k views

Could an organism have evolved to kill its prey by shouting at it?

I've recently been replaying Skyrim (for about the fifth time now), and I've stumbled across something I thought would make for an interesting question. The Greybeards are a group of extremely ...
48
votes
11answers
15k views

Given immortality can animals become intelligent?

The animal in question starts off with reptile like intelligence, classic gecko and is a singularity, the only individual of his species to be immortal. It can die and be killed but for the sake of ...
48
votes
10answers
14k views

How could we time travel backwards without killing everyone with germs from the future?

Consider a world in which time travel has been made viable possibility. Initially, many are ecstatic at the new technology and the knowledge it will unlock. However, biologists and other scientists ...
47
votes
15answers
13k views

What injury would be of little consequence to a biped but terrible for a quadruped?

Let's imagine a group of people who can turn from human to wolf at will. Wolves are quadrupeds, and humans are biped, so I guess their weight is differently shared in their body, notably when they ...
47
votes
11answers
8k views

Is it possible for two symbiotic lifeforms to be born from the same egg?

Firstly, I'm not looking for an organism that gives birth to two separate species (like a human that gave birth to a human baby and a puppy) as I'm fairly sure that is impossible (though feel free to ...
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 ...
47
votes
10answers
5k views

How can an organ that provides biological immortality be unable to regenerate?

After Cain killed his brother Abel, he was cursed by God to wander the earth forever. On his travels, he met a sympathetic woman named Lilith. They discovered that they had a mutual beef with their ...
47
votes
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 ...
46
votes
22answers
7k views

Advantage of luminescent eggs?

For example, a quote from one of the Witcher 3: Blood and Wine's side quests says The eggs themselves are a sight to behold, luminescent. The man (hologram) is referring to giant centipede eggs. ...
46
votes
18answers
14k views

What would be the possible benefits of pointed ears?

The title fairly well sums up the question. We all know elves have pointed ears. Whether they be LotR style with slight tapers, or full blown foot long impracticalities, all elves have pointed ears. ...
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 ...
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
7answers
28k views

If accelerated natural healing were to occur, what would happen to the human body?

The Details: The human body is capable of impressive acts of self-repair, but such processes take a lot of time, and can take a toll on the body. Infection or other complications can also develop, and ...
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 ...
44
votes
15answers
13k views

How could elves survive without any fat cell in their body?

Have you ever seen a fat Elf? I haven't, and I think there's an unexpected reason. You see, Elves aren't really the best workers or at least working the land and cultivating food is not something ...
44
votes
8answers
10k views

Is it harder for an intelligent octopus to live on land, or a human to live in space?

I have a race of octopodes with the same intelligence distribution as humans. I want them to “colonise” land to a similar extent as we have “colonised” space; have regular transport between the ocean ...
44
votes
4answers
7k views

How many people would have to be killed to make the streets 'run red with blood'?

For example, a street this wide to have enough blood run down the length shown in this photo? Assume that the blood isn't going down storm-drains for whatever reason and assume the stretch of road is ...
43
votes
9answers
9k views

Is an organism with both animal-like traits and plant-like traits scientifically possible?

Can an organism have traits that resemble both an animal and a plant? Such as bone, chlorophyll, muscles, and cell walls. Not necessarily a hybrid, but something that can be classified in between the ...
42
votes
8answers
13k views

Could a plant grow on a restrained, living human?

My question is: Could a macroscopic (e.g. visible) plant grow on a living human, provided that the human is completely immobilized?
41
votes
9answers
9k views

How could I scientifically explain ice breath?

I'm sure there have been questions on here about fire-breathing dragons, and I recently saw a question about a lightning-breathing dragon, but back in fifth grade I wrote a 150-page story about a ...
41
votes
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 ...
41
votes
8answers
4k views

A three foot cell?

In one of my fictitious planets, there are large cells that reside in the ocean and are 3 feet (almost 1 metre) in diameter. The cells themselves are aggregates of many amoeboid cells, have only one ...
40
votes
11answers
9k views

How do I explain a unicorn discharging powerful electricity at a distance?

I am thinking of copying the design of an electric eel to create the horn, however as air is not a good conductor of electricity it cannot discharge any electrical shock unless there is a physical ...
40
votes
11answers
14k views

How would a human livestock facility run by aliens operate?

The older man looked at the younger one. He took a deep breath and began to tell his tale, just like he was told before when he himself was that young. I've been here way longer than you, let me ...