Questions tagged [mammals]

Questions related to mammals, animals that nurse their young, have a neocortex, and three middle ear bones.

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1answer
146 views

Heteromaternal Superfecundation - Any known cases?

Superfecundation in mammals (fertilization of two or more ova from the same cycle by sperm from separate acts of sexual intercourse) -- Is possible in nature from different fathers (Heteropaternal) as ...
2
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0answers
15 views

Does level of bats activity differs from day to day?

Say we measure bats activity as number of passes through given area. Can it differ significantly depending from day to day or it stays on average roughly the same? I am wondering whether the following ...
5
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1answer
631 views

The ermine's colour and geographical range

Ermines turn white during the winter, with only the tip of the tail remaining black. However, in the southern regions of the ermine's range it clearly doesn't get so white. Encyclopedia of Life says ...
3
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1answer
277 views

Why do surface mole tunnels follow directly below the electric fenceline

I have electric fencing enclosing five acres, and moles always seem to tunnel in a straight line just under the electric fence - are they following a force field? Can that be?
9
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2answers
219 views

How can bats achieve good resolution with wide beams?

I have been reading about the echolocation system in bats. papers state that bats tend to produce a sonar beam that has a beam angle (-3db) of about 30-40 degrees. This would be considered a wide beam ...
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1answer
64 views

Why do teeth decay of sugar?

Sugars is a common component in diet of mammals. Why then their teeth did not develop resistence to sugar decay?
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1answer
293 views

Mammal vs Placental Mammal

So for Google Earth Day's quiz I ended up being a "Pangolin." Turns out I had no idea what it was so I looked into it and honestly it reminded me a lot of an Armadillo. So I decided to find out the ...
21
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2answers
32k views

How and why did mammals go back to the oceans?

If I understand evolutionary biology correctly, mammals first evolved on land as small, rodent-like creatures, in a time when reptiles were dominant on land. Eventually, they diversified into the ...
3
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0answers
35 views

Why there are two rounds of cytosine de-methylation in mammalian development?

I assume that the key biological meaning of cytosine de-methylation during germline development in germline progenitor cells is to reset imprinted genes and then set methylation pattern on these genes ...
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0answers
87 views

How important is the womb's environment?

- Background - Talking about one phenotypic trait, the total phenotypic variance $V_p$ is decomposed into genetic and environmental variance for this trait, represented by the symbols $V_G$ and $V_E$ ...
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0answers
65 views

How do I get recombinant proteins into the nucleus of mammal cells?

I know that there are Nuclear Localisation Sequencenes (NLS). They can be taken from endogenous or viral proteins and fused to the N or C terminus of my recombinant protein. Which is the best one? ...
0
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1answer
188 views

What is the evolutionary purpose of white spots in nails and how can they be characterised due to Leukonychia? [closed]

Suppose you haven't hit your nails so the white spots are due to Leukonychia. Are the discoloration i.e. the white spots due to lower porosity (less minerals absorbing) or some other factor? I ...
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2answers
2k views

Why only female mammals have well developed mammary glands?

In course of evolution (possibly), mammary glands became vestigial in male mammals, but became fully developed in females. Is there any plausible explanation for this characteristic?
6
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1answer
849 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 ...
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0answers
44 views

Are there any mammals whose males can feed with milk? [duplicate]

Are there any mammals whose males can feed the offsprings with milk from the breasts?
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0answers
38 views

Which agricultural crops attract rodents?

Are there any data on rodent populations per acre of different types of agricultural crops?
4
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1answer
233 views

What does it mean for the signals for transcription and translation to be “conserved”?

I was reading this article: "Overview of vector design for mammalian gene expression." for an explanation of why mammalian cell lines are used for expressing cloned genes, and one of the reasons ...
13
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3answers
3k views

Why is mammal coloration so dull?

I have seen species of birds, insects and fishes with splendid colours. But when it comes to mammals (including us humans), they almost always appear in shades of brown, grey, orange, or in black and ...
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1answer
69 views

About the plight of Elephants and efforts to conserve them? [closed]

Poachers are only after the ivory horns right? I read this story from the New York Times ( I think) of saving a Rhinocerous by some Park Rangers and a Vet. ( forgive spelling) ; they tranquilized the ...
7
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1answer
215 views

Why are recombination rates increasing in mammals?

I have recently become fascinated with an awesome topic in biology and evolution that I feel is rarely covered in biology courses. That is, rates of meiotic recombination, or the the amount that an ...
7
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2answers
646 views

Why does botulinum toxin seem to be more dangerous to humans than to other mammals?

Various mammals seem to get away with eating parts of carcasses that we would prefer to not even touch, and that we assume will make us sick. Because of that, I assume botulinum toxin is more ...
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5answers
11k views

Why do most mammals have long snouts?

It seems like most mammals, e.g. dogs, have long snouts. My pet dog's snout would seem to me like an evolutionary disadvantage, since her canine teeth are way out at the end of her jaw, which acts as ...
1
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1answer
45 views

Book recommendation on mammal (or just primate) behaviour, especially in relation to child-rearing

I have a growing frustration with the lows 'new-age' parenting is reaching, along with asininity of so much of our public schools' (and summer camps') philosophies and policies in relation to our kids....
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2answers
3k views

How do bats distinguish between day and night?

How do bats distinguish between day and night? Do they hunt at night - if yes, how they know that? Are they afraid of sunlight?
4
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1answer
3k views

How do Kangaroo mothers deliver the correct kind of milk to the correct joey?

Mother kangaroos are able to rear multiple joeys (young kangaroos) at different stages of development at the same time. According to Wikipedia, "the mother is able to produce two different kinds of ...
8
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1answer
821 views

What species is this mammal?

I saw a mammal that looked like a large squirrel. I haven't seen anything quite like it. Can you help me identify it? Squirrel-like, "hunched over" posture. It was too large to be an eastern squirrel&...
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1answer
185 views

How compatible are mammalian digestive systems?

I'm interested in what kinds of nutrients mammals extract from food and would like to know how similar are the outputs of these systems. For example, if it is possible to successfully replace one ...
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2answers
522 views

Does Science Say That We Should Die? [duplicate]

Excluding situations where you die from accidents, the main reason for death is -generaly- diseases. And usually it is about an organ which becomes "tired" after many years. These results are all ...
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1answer
76 views

In what circumstances does a mammalian egg copy its DNA?

In the 2nd episode of the new Cosmos series, the host Neil deGrasse Tyson shows how the white-furred bear could have evolved (reasonable scientific speculation, of course). If you haven't seen that ...
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1answer
1k views

Are females more flexible than males in all mammals?

It's common that human females have a more flexible body than males, (but I don't know why, so it'd be helpful if someone answers why so as well!) but does this apply to all mammals?
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3answers
168 views

laboratory mice, nutrition, and humans

It seems that many nutrition experiments [directed at human diet] are carried on laboratory mice. Is there any justification that nutrition that is good or bad for laboratory mice will also be same ...
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1answer
122 views

Why do mammals in the wild retain the “trait” of menstruating with blood? [duplicate]

This question intrigued me a lot since if animals in the wild did have menstruation with blood flow, wouldn't all that blood be attracting every other predator in the vicinity?
3
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1answer
2k views

Is there a difference between pig and cow anatomy that makes religious slaughter of the latter less painful?

This question is not for the squeamish. I was told that non-Kosher animals like pigs have a different anatomy in their neck compared to kosher animals like cows such that the Shechita method of ...
4
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1answer
944 views

How are blood vessels affected by UV and infrared radiation?

The lining of the blood vessel as an interface and boundary layer is of existential necessity to the life-support of mammals. My question is: How are major blood vessels and the blood vessel lining ...
5
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1answer
79 views

How do rodenticides with delayed effect work?

Most modern rodenticides are claimed to cause death no earlier than several days after ingestion. That's quite strange - once a chemical was ingested it will be absorbed in the digestive system and ...
6
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1answer
115 views

How compatible are mammal wombs?

I had read about science working towards the creation of artificial wombs however I wonder how compatible are mammal wombs and connected systems to develop fetuses. What species are so compatible that ...
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1answer
530 views

Are ape communities more “anarchist” or “communist” in structure?

I am using these terms because we can imagine them quite good, I guess ;) By "anarchist" I mean that the ape wants to live without the rule of others apes(same biological race or other) and he pursue ...
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0answers
6k views

Can Squirrels Eat Every Mushroom? [closed]

Squirrels have the ability to eat toxic mushrooms as described below. Are there any mushrooms that they can't eat without dying? According to Dr. John Rippon, an IMA member and world expert on ...
4
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1answer
1k views

Why do sloths come down from the trees to defecate?

I'm under the impression that most sloths exhibit this behavior, but why? They are slow moving and so have no way of escaping from predators when on the ground. Not to mention the energy they expire ...
3
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2answers
137 views

Do dolphins really sleep?

I have always wondered, if dolphins sleep with one eye opened, do they really sleep at all? According to this article dolphins indeed shut down their brains. I already googled it. No help from ...
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2answers
771 views

Do any cells change in size or mass as mammals grow?

That is to say, are there cells that, between infancy and adulthood, get larger? Or is all growth done entirely via cell division? I'm wondering if it is safe to assume that the approximate number ...
6
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1answer
437 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 ...
6
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2answers
242 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 ...
5
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1answer
340 views

Why was polyploidy not lethal in certain octodontid rodents?

As discussed in Why is polyploidy lethal for some organisms while for others is not?, polyploidy is normally lethal in mammals. However, two species of Octodontidae (South American rodents), are ...

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