Resonating
  • Member for 8 years, 4 months
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2 answers
32 votes
5k views
How do we know the human species arose in Africa?
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51 votes

There are two big prongs of the out of Africa theory or whichever name you wish to call it. Prong the first: fossil evidence. There are lots of different kinds of protohuman fossils. Homo erectus/...

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2 answers
14 votes
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Do electromagnetic waves outside the visible spectrum have any role in photosynthesis?
20 votes

Photosynthesis is nearly all visible light. There's usually not enough UV and thermodynamics more or less rules out infrared. Chris covered that pretty spectacularly, but that nearly is significant. ...

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2 answers
17 votes
1k views
Are two colors (red + blue) necessary for LED grow lights, or would either color be sufficient?
13 votes

tl;dr: Sort of? Logically, either red or blue light should be sufficient. Chlorophyll a and chlorophyll b preferentially activate different photosystems, and both photosystems are required in green ...

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1 answers
10 votes
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Regarding the kingdom Animalia, which phylogenic tree is more common: Molecular Comparisons or Body-Plan Grades
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12 votes

Long story short, use sequence information if you can. The long story long: Sequence information and the trees generated from them are strictly more reliable than morphological characters. For ...

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4 answers
17 votes
26k views
Why do we have no enzyme to digest cellulose?
12 votes

While it's true that cellulose is full of calories, it's very difficult to get the calories out. Symbiotic bacteria take ages to digest cellulose, and as a result animals that digest cellulose with ...

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2 answers
17 votes
11k views
Why does sex last so long?
8 votes

I'm going to give a tentative answer full of speculation and guesswork, but it's too long to fit in a comment so here goes. Sex duration is possibly a sort of human reproductive handicap. Sexual ...

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2 answers
12 votes
4k views
Can we make a rough estimate of the number of generations since the origin of life?
6 votes

If you're willing to accept many orders of magnitude and define life as the Last Universal Common Ancestor. For the rest of this answer, life begins 3.5 Gya with cyanobacterial mats and stromatolites ...

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2 answers
7 votes
1k views
Can carnivores survive on a (processed) vegetarian diet? Why or why not?
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6 votes

With arbitrarily broad meaning of "processed", yes. If absolutely nothing else, elemental purification and inorganic synthesis of something chemically resembling meat in nutrition is possible. ...

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3 answers
19 votes
9k views
Why is green fur not a thing?
6 votes

A dimension not explored by the other (excellent) answers has to do with color perception under trees. Leaves are green while on the tree, which tends to make mostly green light available to the ...

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2 answers
5 votes
856 views
Breakdown of energy expenditure at the level of a single cell
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6 votes

I was musing on this and did some strange googling, and have some ballpark figures for a bunch of different organisms. It's far from a complete answer but it's at least a start, and all this won't ...

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2 answers
2 votes
140 views
Collective term for both exons and introns
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6 votes

How about "splicing fragments"? It might be easier to refer to them according to the mechanism of production.

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1 answers
4 votes
501 views
What is this plant/creature in my freshwater aquarium?
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5 votes

That is a hydra. They are a kind of jellyfish, and as such they do technically have stinging tentacles. However, they're also very small, so they're not a danger to most fish or shrimp. If you're ...

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4 answers
26 votes
6k views
How to get rid of mosquitoes in a small lake
5 votes

Don't salinate the lake. It'll be a nightmare to maintain. The 'standard' biocontrol measure is to release 'mosquitofish', but outside their native range they're almost as good at killing native ...

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1 answers
6 votes
4k views
How does pressure measured by sphygmomanometer translate directly to blood pressure?
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5 votes

Korotkoff sounds! The blood pressure measurement process is fairly cool, and goes like this. Inflate the cuff to well over plausible blood pressures (250mmHg or so). Slowly deflate the cuff while ...

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2 answers
5 votes
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Can plants live forever?
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5 votes

The answers to these questions often boil down to "what do you mean by live forever?". You've included vegetative cloning, so I infer that counts as one living organism for your purposes. In that ...

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2 answers
2 votes
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Almost philosophical question about controlling a pest/plague
5 votes

Biologists are certainly not afraid to exterminate pests and plagues in the wild. See: smallpox and polio. However, such exterminations are nearly impossible and very expensive. See: smallpox and ...

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1 answers
4 votes
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Why are low temperatures lethal?
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4 votes

Low temperatures change the speed of different chemical reactions, throwing delicately balanced systems out of balance. How resilient a creature is to temperature changes is largely a function of how ...

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1 answers
2 votes
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What makes a good phylogenetic tree?
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4 votes

A 'good' phylogenetic tree would be completely refined, properly binary, have high bootstrap support for all its branches, and reconstruct clades we think exist with high support values. Generally ...

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1 answers
2 votes
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How much is local blood non-Newtonian in Pathophysiology?
4 votes

According to this conference proceeding blood is very nearly newtonian at normal shear rates. More accurately blood is very thick and a shear-thinning fluid, but the shear-thinning effects don't scale ...

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1 answers
2 votes
172 views
Is there an evolutionary advantage for coconut oils to be rich in saturated fats?
4 votes

This is entirely speculation, but the part of seeds that is pressed for oil(the endocarp) is enriched in saturated fats and long fats in ocean-going fruits. The coconut is 91% saturated fats, the oil ...

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1 answers
1 votes
71 views
What would happen if most the fat in your body was rapidly converted into energy in 2 minutes?
4 votes

It depends, but you're going to die. Specifically, it depends on how fat you are. Even Andreas Munzer is going to die. At only 3% body fat, burning all his fat (9kcal/g) would "only" increase his ...

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1 answers
3 votes
4k views
Is household ammonia okay for plants?
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4 votes

Okay, he's not wrong, technically speaking. Practically speaking never ever fertilize your plants with ammonia. The ammonia you spilled will be converted into nitrates eventually, so it's not like ...

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1 answers
3 votes
886 views
How fallible are DNA paternity tests?
4 votes

Discounting lab error and other kinds of human incompetence, there aren't very many things that can confound a paternity test. Normal DNA damage cannot, but there are kinds of genetic chimeras that ...

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1 answers
8 votes
3k views
How can flies sense mirrors?
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4 votes

It might be pretty straightforward. Common window/mirror glass is opaque to UV, so as far as the fly is concerned mirrors are just translucent surfaces. This of course leads to the question of why ...

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1 answers
1 votes
105 views
Is it possible for neurons themselves to manifest cancerous behavior?
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4 votes

Yes, but rarely. Other types of brain cells are much more likely to form tumors. Oligodendrocytes, astrocytes, and more generally glial cells all form tumors with some regularity. Nerve sheaths can ...

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5 answers
10 votes
2k views
Why is the human body able to repair a broken bone and not a heart muscle?
4 votes

The heart does have stem cells in it, and there is cell turnover in the heart, of about 1% per year. Which is much slower than your skin, but not nothing. This allows your heart to grow during your ...

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2 answers
1 votes
371 views
How to compare Smith–Waterman algorithm implementations?
3 votes

There are only two possibilities for Smith-Waterman alignment with a given cost matrix. It's either right or it's not. Honestly, whatever you're using, it's really really unlikely that a pure Smith-...

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1 answers
3 votes
300 views
Inheritance patterns in individuals with triploidy
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3 votes

Triploids are characteristically sterile, but people with Down's Syndrome aren't triploid(they're anueploid technically). There's only one chromosome duplicated, and it's the smallest one. Women with ...

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1 answers
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Absorption of Topical Magnesium
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3 votes

Homeopathic magnesium lotions don't* contain magnesium, so it seems a little irrelevant whether or not magnesium can be absorbed through the skin. However, magnesium ions can definitely be absorbed ...

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2 answers
8 votes
234 views
How do we know that ammonites are a kind of cephalopod rather than another type of mollusc?
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3 votes

It really is mostly the siphuncle as @augurar mentioned. The siphuncle is present in modern ammonites, cuttlefish, and Spirula(a deep-sea squid with an internal chambered shell). It links shelled ...

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