2
votes
1answer
333 views

Fossils of intermediate stages?

If Humans are evolve from Monkeys, there must be stages in the evolution process, when it was 1% human and 99% monkey, 2% human and 98% monkey and so on. This is because evolution was a very slow ...
5
votes
2answers
267 views

How does fever physically work?

What is the physical mechanism that causes temperature to rise during a fever? I know that somehow the hypothalamus "orders" to increase the standard body temperature regulation, and this should ...
10
votes
1answer
315 views

What are the “stars” we see after a bump on the head?

Sorry if this might appear funny. When I close my eyes for a longer time, and suddenly open it, I see some twinkling white small circles, and when i concentrate on anyone of them it disappears, as ...
8
votes
2answers
2k views

Preferred Aspect Ratio for Human Eyes

Our eyes are spherical, our retina is circular, but still our eyes can see more in the horizontal direction than in vertical direction. Why is it so, why is the preferred aspect ratio not square? ...
4
votes
1answer
213 views

Do any birds beside the family Columbidae (or any reptile or mammal) feed their young “Crop Milk”

Birds from the family Columbidae (e.g., doves and pigeons) produce a fatty, milk-like substance in their crop. The secretion is often referred to as "crop milk." They feed crop milk to their young ...
7
votes
3answers
174 views

How does one maintain balance sleepwalking?

Anectodal. Feel free to shoot it down. Walking is an acquired skill; As far as I'm concerned exhaustion causes disorientation. Even after waking up it sometimes takes a second or so to get balanced. ...
1
vote
3answers
246 views

What difference does it make in the organism's physiology/metabolism whether oxygen binds reversibly or not?

A follow-up to How does hemoglobin-free blood transport oxygen? I'm unsure about the use of physiology/metabolism in the title there. The question in mind is whether this reversible binding makes an ...
5
votes
1answer
165 views

Tuna fish in Baltic sea?

Yesterday my grandmother ate fresh tuna at a friend's party. She swears it was fresh and bought at a local fish-shop. The problem is, that we live in Gdańsk, by the south-eastern side of the Baltic ...
6
votes
1answer
100 views

Does artificial heat (shower/tea) affect diurnal rhythms in humans?

I've been reading that over the course of the day, human body temperature follows diurnal rhythm with the lowest body temperature observed some time close to the middle of the sleep episode, while the ...
2
votes
1answer
60 views

Diet of free-range herbivores

Giving minimal credence to estimates in popular media of the average biomass of insects/arachnids, etc. in an acre of land, it seems that a "free-range" cow (I don't mean to pick on cows) might be ...
4
votes
1answer
247 views

How does hemoglobin-free blood transport oxygen?

Snails... We have some kind of huge garden snails appearing lately (read since the last 10 years or so). Try as one might, it's impossible to avoid them when driving. These snails do not appear to ...
8
votes
1answer
298 views

What hair do aquatic mammals have?

I'm reading an essay on the creating of the Mammalia zoological classification (Londa Schiebinger, The American Historical Review, Vol. 98, No. 2 (Apr., 1993), pp. 382-411). It contains the statement ...
1
vote
2answers
287 views

Effect of extracellular molecules on membrane potential

I am reading about the effect of extracellular potassium and chloride on the membrane potential, and now a question has come to my mind about what would happen if we added some molecules that have no ...
11
votes
2answers
641 views

Are the inverse problems of Systems Biology impossible to solve?

I have heard Sydney Brenner give a talk (see link below) on how the entire program of Systems Biology is suspect because, according to him, a chap named Hadamard showed that inverse problems are ...
3
votes
1answer
157 views

Statement about Tropical Rainforests

I made a statement about tropical rainforests, and I want to know if it's somewhat true or not: The soil in tropical rainforests is not exceptionally fertile, because it contains few minerals. The ...
5
votes
1answer
146 views

What selective factors drove the evolution of lactose in lactation?

As far as I can determine, lactose, and the monosaccharide galactose have few biological uses outside of mammalian lactation. It not only required enzymes for its production, but enzymes in offspring ...
2
votes
1answer
52 views

PGC-1β Sod2 limiters/blockers

I'd like to block a percentage of PGC-1β or Sod2 expression. According to the following paper's figure beta-blockers inhibit some expression of PGC-1α. Are there any medicines/chemicals which safely ...
10
votes
4answers
1k views

Does pheomelanin have a useful biological function?

Melanin is a natural pigment that is categorized into two main forms, eumelanin and pheomelanin. It's well documented in the science literature that increased eumelanin levels reduces the risk of ...
2
votes
2answers
120 views

Is there some branch of biology that deals with the entire organism?

I'm reading about various parts of the human body and brain and started to wander if there's a branch of biology that deals with the entire human? I know that there are branches various -biologies, ...
3
votes
1answer
49 views

mutant down but not out

I am interested in a gene which is null lethal but I need to temporary induce diminished capacity. If a cell is homozygous is it possible to induce heterozygous phenotypes or a partial knockout from ...
6
votes
2answers
165 views

Do omnivore mammals vary food preferences based on dietary needs?

I'm wandering if mammals that can eat many different kinds of food (omnivores) vary their preference for food not only based on the availability, but also based on dietary needs? I'm looking at this ...
2
votes
1answer
207 views

What marine animals exhibit deep hibernation/aestivation?

Do marine animals exhibit deep hibernation/aestivation as land-based creatures do? If not, Why?
10
votes
3answers
4k views

How does sodium in one's diet affect blood pressure?

Due to high blood pressure, my doctor has recommended I go on a low-sodium diet. So, that got me wondering what it is about sodium that drives this recommendation? What does sodium do to a body ...
4
votes
1answer
264 views

What is the molecular basis of hangovers?

Well, most of us have experienced the wonderful feeling of the dreaded hangover. How does it work exactly? I imagine it has something to do with dehydration but what are the underlying mechanisms? ...
1
vote
0answers
59 views

Does Dorsal Raphe Nuclei firing pattern change in response to voluntary breathing?

I'm reading this paper, which discusses how Serotonin may be involved in motor functions of mammals: 5-HT and motor control: a hypothesis . The paper includes the following diagram of the Dorsal ...
9
votes
1answer
266 views

Can cancer grow forever if supplied with unlimited resources?

If somehow a human could give a tumor unlimited resources, would the cancer grow forever? It seems like it would until it gets so large that it physically affects vital organs. Is what would likely ...
8
votes
1answer
423 views

Can Bioluminescence drive photosynthesis?

I'm trying to construct an anaerobic kitchen-waste digester at home. The major output from the digester is methane - with a significant component of carbon dioxide. To scrub/reduce the CO2 I was ...
5
votes
1answer
128 views

Modern reference for Kropotkin's lazy bees

I have been reading through Peter Kropotkin's Mutual Aid: A Factor of Evolution and he mentions a curious fact about bees (bolding by me for emphasis): predatory instincts and laziness continue to ...
2
votes
2answers
163 views

Is better healthcare a bane to the long-term survival of the human race?

The theory of natural selection has it that individuals with better genes tend to survive and reproduce, passing their genes to their offspring. This gradual process results in a population more ...
2
votes
1answer
92 views

What triggers creative thought in humans?

Creativity, innovation and ideation. Is there something in the brain that makes the brain think that way, as opposed to "normal baseline". What triggers creative thought in humans?
4
votes
1answer
430 views

How useful are vitamin and trace element additions in E. coli culture medium?

In protocols for minimal media for growing bacteria I often see that a vitamin mix or a mix of various trace metals is added. But at least for E. coli I know that those are not strictly necessary, ...
10
votes
2answers
330 views

Is there any evidence that a virus can modify human evolution

I was just reading Evolution of lactose tolerance, and in it one line says "But there was a time in human history when our diet and environment conspired to create conditions that mimicked those of a ...
3
votes
1answer
326 views

Do all sea creatures that have scales have to have fins?

Do all sea creatures that have scales have to have fins? Do we know of any sea creatures that have only scales without fins? I'm especially interested in fish that have scales but no fins.
2
votes
1answer
345 views

Screen brightness for reading in dark room [closed]

While searching online I did not find any conclusive article on whether it is good or bad for one's eyesight to read on a computer screen in a dark room. Most mention that it will cause strain that ...
4
votes
2answers
61 views

Is there a circadian component to hunger?

I'm wondering what produces the feeling of hunger in humans. Checking Wikipedia revealed that leptin and ghrelin are two hormones involved. I've also read that the digestive system produces its own ...
2
votes
2answers
291 views

Do foods with preservatives become less toxic in the gut?

Do foods with preservatives stay digestible for longer in the gut by not rotting as much (producing less toxins)?
2
votes
2answers
53 views

What do breeders call the effect when a breed resists modification?

It is impossible to breed a blue rose or a cat with a bulldog shape. This is because breeding is limited by gene variations in the population. What do breeders call this effect? UPDATE I guess ...
2
votes
1answer
59 views

Is There An Initiative To Sequence The Genomes Of Critically Endangered Species?

I realize that there are many isolated efforts to sequence the genome of a particular endangered species such as the orangutan or the snow leopard. However is there a concerted effort to sequence the ...
2
votes
1answer
87 views

Why glycoproteins are better than non-glycoproteins in fulfilling biological tasks?

I have just an intuition that the carbohydrate part of glycoproteins help them to fulfil those tasks like in plasma membranes. You can also get many more receptors if you can use carbohydrates too. ...
3
votes
1answer
126 views

An unexpected mushroom in my garden

My grandma is a great fan of mushrooms and knows quite a lot about them. About 10 years ago, she started throwing out mushroom remnants in one special place, in order to grow her own mushrooms. In ...
3
votes
2answers
228 views

Does the speed of electrical impulses through neurones decrease with age?

From what I read on the NatGeo app, it stated that the speed of the electrical impulses that are sent by a neurone will be approximately 332 kilometers per hour. Will the speed of this electrical ...
3
votes
1answer
2k views

Slow-oxidative fibres vs fast-glycotic fibres

Why do slow oxidative muscle fibres contain more mitochondria compared to fast-glycolytic muscle fibres?
3
votes
1answer
69 views

How are atoms in benzopyridines and benzopurines numbered?

I am well-aware of the numbering system used for the traditional bases, as seen below. My question is how are the atoms in the size-expanded bases seen in xDNA and xRNA numbered?
2
votes
1answer
64 views

What are the distinctive structural features of single- or double-stranded xRNA, or where can I find them?

I am interested in the structural differences caused by benzopurines and benzopyrimidines at the oligonucleotide level between RNA and xRNA, both in single-stranded and double-stranded form. I am ...
4
votes
1answer
250 views

How quickly can the human heart rate rise and fall?

How quickly can the human heart rate rise and lower? For example lets say a human heart rate is rested and is at 60BPM and that person is suddenly scared to trigger their fight or flight reaction. ...
2
votes
2answers
202 views

Filamentous algae - what exactly am I looking at?

I have just taken some images with my light microscope at 400x of (what I think is) some form of filamentous algae from a local pond. Now, I think I am looking at a single cell (centre) with some ...
7
votes
2answers
118 views

A mathematician's confusion regarding parametric $t$ tests for gene expression data

I'm a mathematician trying to test some things on gene expression data, and I'm thus skimming over various articles such as Sotiriou et. al. to understand what is typically done with such data sets. ...
18
votes
6answers
819 views

How is evolution possible in contemporary humans?

I would like to know if evolution is continuing to happen in modern humans, assuming things like existence of the nuclear family structure, fidelity to one partner, etc. It seems to me the answer ...
6
votes
1answer
426 views

$S_{0.5}$ vs $K_m$ values in enzyme kinetics

What is the difference between $S_{0.5}$ values and $K_m$ values in enzyme kinetics?
5
votes
1answer
203 views

What evolutionary pressures pushed Galápagos tortoises to mature so slowly and live so long?

I read that they take up to 40 years (in the wild) to reach the age of reproduction and are thought to live over 100 years, with one in captivity reaching over 170 years. Can someone explain in ...

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