The biological study of animals
25
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2answers
504 views
How do cockroaches resist the effects of ionizing radiation?
Cockroaches are very hardy insects. It is known that, among other things, they are able to withstand bursts of ionizing radiation that would kill a human being.
The explanations of this observed ...
23
votes
2answers
301 views
What are the trajectories of flying insects?
Many flying insects tend to have very jagged trajectories. For moves of a fruit fly looks like a random walk.
Is there any research on the properties of trajectories (e.g. their fractal dimension or ...
20
votes
4answers
521 views
Why do men have nipples?
I'd be tempted to call nipples in men vestigial, but that suggests they have no modern function. They do have a function, of course, but only in women. So why do men (and all male mammals) have them?
...
17
votes
1answer
243 views
Why do ants live so long?
I was surprised to learn that worker ants in some species live many years. I would have expected a lifespan of a few weeks or months (which is apparently the case for many species).
What factors ...
16
votes
3answers
206 views
How is the blood volume of a living organism measured without killing it?
How is the blood-volume of an organism measured without killing it? NOTE: The blood-volume of an organism is defined as the total volume of blood present inside that organism.
14
votes
3answers
776 views
Why are there no wheeled animals?
In physics, "almost everything is already discovered, and all that remains is to fill a few unimportant holes." (See Jolly.) Therefore, on Physics SE, people are veering off into different directions: ...
14
votes
1answer
116 views
Are there dextral/sinistral higher animals?
For example, almost every dog I've met in my life (more than 20 subjects) uses their right paw touching one while asking for attention. Can it be used as a criterion for calling them dextral? If not, ...
11
votes
4answers
2k views
Do cows produce milk excessively?
Do cows produce more milk than it is required for their calves? It seems like cows are able to provide milk all the time (all year around). Is it so? Or do they, like other mammals, produce milk only ...
11
votes
2answers
830 views
How do insects breathe?
Do ants even breathe? If they don't, how do they stay alive? On what resources do they depend upon to stay alive? How are they different form mammals?
11
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1answer
199 views
How do porcupines keep from pricking each other while mating?
How do porcupines keep from pricking each other while mating? It seems like they would constantly be scratching each other.
11
votes
1answer
197 views
How do members of cryptic species know who to mate with?
According to Wikipedia:
In biology, a cryptic species complex is a group of species which
satisfy the biological definition of species—that is, they are
reproductively isolated from each ...
10
votes
1answer
146 views
Are there any pre-Holocene venomous animals?
The novel (and subsequently movie) Jurassic Park featured a dinosaur called Dilophosaurus, that was purported to be venomous and had an ability similar to that of the extant spitting cobra. ...
10
votes
1answer
333 views
Do large animals often evolve into smaller animals?
There are several examples where the largest animals were killed off preferentially due to a major ecological shift:
The KT extinction event
The Holocene extinction, as well as the major megafauna ...
10
votes
3answers
98 views
How do baby animals that primarily subsist on cellulose get their initial gut flora?
In the case of mammals like giraffes and koalas, is that bacteria common on the plants they eat so when a baby starts to try to stick something besides its mother's milk in its mouth, it can't digest ...
10
votes
2answers
192 views
Why do pandas have a high probability of giving birth to twins?
According to the BBC documentary "Wild About Pandas", about half of panda birth result in twins. Why do they have such a high probability compared to other mammals? What factor(s) control that ...
10
votes
1answer
986 views
Fish “coming back to life” after being frozen
I've encountered a clip on Youtube showing a goldfish thrown in liquid nitrogen and immediately after to normal water and swimming normally. In the explanation to the clip it says:
For everyone ...
10
votes
1answer
660 views
Why do we grow so much hair on our heads compared to our bodies?
I've been wondering about head hair, facial hair in particular. Human males can grow very extensive beards should they choose to not shave - however you do not really see this in our chimpanzee ...
9
votes
1answer
616 views
Do fish break a water molecule to absorb oxygen?
How do fish separate oxygen from H20 & consume it? Do they break the water molecule and absorb the oxygen only?
9
votes
2answers
834 views
Did animals evolve from plants?
Did animals evolve from plants? Did the animals' ancentors have chloroplasts in their cells?
9
votes
4answers
160 views
What was the reason for some plant and animals to become giant in course of evolution?
The dinosaurs, mammoths, giant plants etc are known to be bigger than modern animals. I wonder why they had been lived and why they are not living now? I really don't know much but is it something ...
9
votes
3answers
158 views
How do we know that dinosaurs were related to lizards and/or birds?
Do we clearly know what the living closest relative of the dinosaurs are? And connected to the first question, in scientific manner how do we know these relationship between extinct species and living ...
9
votes
1answer
93 views
Why is there a difference in the rotation of the tail fin in fish compared to marine mammals?
I've been thinking about this one, but I can't seem to find what causes this difference.
All fishes that I've seen have their tail fin positioned vertical:
But all the marine mammals I know have ...
9
votes
1answer
228 views
Examples of animals that co-opt toxins?
It is known that there are animals that acquire toxins through their diet or through their surroundings. The examples I know of include butterflies stocking up on alkaloids/glycosides while in the ...
9
votes
3answers
608 views
Species with reproduction barriers that can both reproduce with a third species
To start with, I do not have a sound knowledge in biology or any formal education in the area.
I was told that one of the definition of a species is a reproductive barrier, which means that if two ...
9
votes
1answer
339 views
How many mice are on the Earth?
We are 7 billion human beings on the Earth. But how many mice are there? How would you estimate such a number?
9
votes
1answer
183 views
How does a jumping spider manage to “jump” on the ceiling?
I just witnessed a small jumping spider jump on some kind of louse or bed bug on the ceiling. How does it do that without falling? I have yet to find a high-speed-camera video of a jumping spider ...
8
votes
2answers
125 views
What are the frequency ranges of most marine mammal vocalizations?
I am trying to determine a list of frequency ranges into which marine mammal vocalizations fall.
Ideally, I would like a list showing where the most popular marine mammal vocalizations fall, followed ...
8
votes
1answer
93 views
Why does the gender of the parent species determines the species of a hybrid offspring
I've read a little about hybrid animals, and have been amazed by the fact that the gender of the parent species determine the species of the offspring, in some hybrids.
A male horse and a female ...
8
votes
1answer
464 views
Will the “frog in boiling water not jumping out” work on warm blooded animals
There is the famous saying about a frog that is put in water that are slowly boiling will not jump out until it's too late. I realize it happens because of the frog's cold blood that adjusts to the ...
8
votes
3answers
179 views
Why is blood pressure higher the more distal an artery is?
Why is blood pressure generally higher in more distal arteries?
8
votes
1answer
160 views
Is the squid giant axon the fastest conducting unmyelinated axon known?
The conduction velocity of the squid giant axon can reach 30 m/s. Is there any known example of an even faster conducting unmyelinated axons?
8
votes
1answer
564 views
How strong is spider silk?
Spider silk is pretty darn strong and all sorts of comparisons are made to steel. I'm more curious about the various moduli of spider silk and how it compares to other materials. What is the Young's ...
8
votes
1answer
149 views
Which organism has the sharpest vision?
Which organism has the sharpest vision in terms of distance and spectrum. Please propose any other useful measure.
8
votes
1answer
80 views
Predators faking to be not hungry?
I believe that there are predator/prey combinations where the prey can easily spot that the predator is not hungry and will not try to flee from it. I’m thinking, for example, of gazelles who will ...
7
votes
3answers
500 views
Why does the butterfly have a cocoon stage in its life cycle?
Why does the butterfly have a cocoon stage in its life cycle? It could have simply grown up within the egg/cocoon, and emerged as a butterfly. Instead it is first an egg, then a worm, then a ...
7
votes
4answers
578 views
If I put a cup over a spider, and leave it there for a day, will the spider survive?
Will it travel more slowly since it hasn't had food for a day?
What if I left the cup there for longer?
7
votes
3answers
115 views
Is the appendix a vestigial structure in all vertebrates?
In humans the Appendix is a vestigial organ. Does it serve no apparent purpose in all the vertebrates that have one?
7
votes
2answers
215 views
Why do stranded marine mammals die so quickly?
Mammals have lungs, so do marine mammals. Nevertheless some marine mammals seem to die rather quickly when they strand on a beach.
As they have lungs and can breath while on land, why do they die so ...
7
votes
1answer
326 views
Do any animals other than humans undergo menopause?
Do any animals other than humans undergo menopause?
Also, is there any difference between animals in captivity and animals in the wild as regards menopause? For example, even if menopause has been ...
7
votes
1answer
54 views
Is there such thing as “meters per calorie” for living organisms?
I'm interested in learning if there's some way of quantifying the organism's metabolic efficiency associated with movement.
It seems to me that some organisms would be more efficient than others at ...
7
votes
2answers
87 views
Is there a term for tool use in animals?
Is there a technical/scientific term that scientists use to refer to tool making abilities found in certain types of animals?
Reference ...
7
votes
1answer
129 views
How can an albatross stay airborne for months?
Albatrosses, of the biological family Diomedeidae, are large seabirds allied to the procellariids, storm-petrels and diving-petrels in the order Procellariiformes. They range widely in the Southern ...
7
votes
2answers
123 views
Are there any structures in mammals that are used only by males?
There are examples of structures which only serve a purpose in females, but it seems like the opposite could also be true. Are there any structures which exist in both mammalian sexes and only serve a ...
7
votes
2answers
186 views
What's the name of this bird?
This morning I saw a bird that I have never seen before. Since it was quite big, I'm very interested in knowing its name.
The bird was quite big, at least 2-3 times of a common blackbird. The wings ...
7
votes
1answer
94 views
Do goldfish really have a 5 second memory span?
I heard that when people place goldfish in another tank, they just forget where they where previously? True or False ?
7
votes
1answer
162 views
Could an animal with an open circulatory system survive in a near-zero gravity environment?
An animal such as a crayfish relies on gravity to keep its circulatory system running. If it is turned upside down, the gravity works against the system, suffocating the animal. Now if, instead of ...
7
votes
1answer
231 views
When do most mammals mate?
Is one part of the day more prevalent then other when it comes to mammal animals mating? Is there an aggregating study that has been done to see if these living beings in nature mate mostly during day ...
7
votes
1answer
235 views
Do egg laying animals experience a pregnancy?
Does a female animal that lays eggs experience a pregnancy-like period of time, where she will feel and behave differently as if she were fertilized and her body is prepared to lay a fertile egg, not ...
7
votes
0answers
90 views
Why do animal teeth get darker if exposed?
I was wondering why the teeth of cats (And dogs, as far as I know, plus possibly some other animals or even humans) get darker if they are exposed to air / light?
Example:
(See the lower end of ...
6
votes
3answers
157 views
Where can I find the common names for the zoology taxonomy?
Forgive me if my question does not belong here or if I'm using incorrect terms, but I'm not educated in biology at all. I'm investigating the workings of the biological classification system.
I was ...
