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1500 questions
66
votes
2 answers
Is there any evidence that sexual selection may lead to extinction of species?
Darwin suggested that sexual selection, especially by female choice, may counter natural selection. Theoretical models, such as a Fisherian runaway process, suggest that evolution of preference and preferred phenotypes may drive each other in ever…
Marta Cz-C
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66
votes
2 answers
Do ants or other insects sleep, and if so why?
I was thinking yesterday about insects (as there was a spider in the house, and I couldn't help but think of anything else, even though they aren't insects), and I started to wonder if ants sleep?
After thinking about it for a while I decided that…
J_mie6
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65
votes
1 answer
What could cause a forest of bent trees?
While hiking on the northern Idaho-Montana border, I encountered a large area where virtually every tree is bent at the base in the downhill direction. Only the very largest and very smallest trees are straight. What could cause this?
Mark
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65
votes
8 answers
Why does evolution not make our life longer?
Why does evolution not make life longer for humans or any other species?
Wouldn't evolution favour a long life?
Majid
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64
votes
2 answers
Why does it hurt the next day after doing significant exercise?
I think this is a fairly common observation that if one does some significant amount of exercise, he/she may feel alright for the rest of the day, but it generally hurts bad the next day. Why is this the case?
I would expect that if the muscles…
user1995
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63
votes
4 answers
Are there organisms with fewer than 1000 neurons?
I'm developing neural networks comprised of just 3 to 10 layers of virtual neurons and I'm curious to know if there are any insect brains out there with fewer than a thousand neurons?
Are there any tiny creatures with small numbers of neurons?
Do…
J.Todd
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63
votes
1 answer
A new species of small bird?
This picture is take from my village in Gujarat, India. I think it is a small bird which I have never seen before. It is smaller than an Indian hummingbird and even smaller than a neem tree leaf. You can see the leaf and the flowers. That flower's…
Dhirendrasinh Sisodiya
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63
votes
4 answers
Why don't mammals have more than 4 limbs?
Arthropods have 6 or more limbs and arthropods with 6 limbs appear to move faster than arthropods with 8 limbs so I wonder whether this might have something to do with fast and efficient locomotion. But, this is just a guess. I wonder what the…
Aidan Rocke
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62
votes
4 answers
How come large herbivores have such thin legs?
Edit:
This question is very similar to this and related to this one (though the latter focuses on homology instead of scaling laws). However, the answer to this question is far more comprehensive, in particular it offers a plausible explanation why…
Kevin Kostlan
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62
votes
3 answers
Why do smaller mammals move intermittently?
I was watching a nice little video on youtube but couldn't help but notice how snappy smaller animals such as rats and chipmunks move. By snappy I mean how the animal moves in almost discrete states pausing between each movement.
Is this a trivial…
Fraïssé
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59
votes
10 answers
Why are there no organisms with metal body parts, like weapons, bones, and armour? (Or are there?)
Reading this question, Why are there no wheeled animals?, I wondered why no organisms seem to make use of the tensile and other strengths of metal, as we do in metal tools and constructions. I am obviously not talking about the microscopic uses of…
Cerberus
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58
votes
2 answers
Are the social-distancing measures implemented against SARS-CoV-2 also suppressing the spread of other viruses?
With social-distancing measures being implemented in many countries I would expect other viruses, like the ones that cause seasonal flus, to have also a hard time propagating in these circumstances. Are there any estimates or research…
Swike
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57
votes
4 answers
Why do the fastest runners tend to be black?
If you watched the last Olympics like me you probably also observed that most medallists in running events were black. Why is that? I discussed this with university grad friends and researchers and we only came up with hypotheses but nobody had an…
Mud Warrior
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56
votes
5 answers
Life without DNA?
I'm by no means an expert in the field, merely a curious visitor, but I've been thinking about this and Google isn't of much help. Do we know of any lifeforms that don't have the conventional double-helix DNA as we know it? Have any serious…
Phonon
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55
votes
7 answers
Why isn't a virus "alive"?
The recent news about a new supermassive virus being discovered got me thinking about how we define viruses as non-living organisms whilst they are bigger than bacteria, and much more complex than we first gave them credit for.
What biological…
James
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