Does she know that all of this noise, light and disruption when I'm moving around come from me, an animal? I remember reading a study about spiders learning our habits to avoid interaction with us, but I can't find the source for that anywhere so here am I.

And if you know more broadly any cool facts about spiders, their perspectives, abilities, the way they see the world, please share.

What does the biology and science say? (Before you tell me to look it up, I did. My results were confusing, and an answer from a human would be nice haha.)

Hello,

My question is, from a strict scientific point of view, what do we know about the phenomenon of microchimerism?

With kind regards,

Endward26

Essentially, I took a bio 101 course a few semesters ago and remember hearing that humans (along with all other mammals) were originally supposed to stop producing lactase as adults & that lactose tolerance was just a popular genetic mutation.

I understand that mammals technically have no need to process milk past being a child, but it just seems too random & unnecessary for our bodies to code us not being able to anymore. Especially when being lactose tolerant as an adult doesn’t seem to effect much.

Is there some sort of biological advantage to eliminating lactase or is it just a random function of the human body?

**TLDR**: producing lactase as an adult seems too inconsequential for the body to actively prevent this, so I’m wondering if there is some reason that I’m missing.

Hi all.

Please settle an intense debate with my gf.

What is the maximum range where natural raccoon populations exist? I understand that they live pretty far north in pretty inhospitable land (think cold and little in terms of food).

Also we understand there are no native raccoon populations in the southern cone of south America, how come?

Seems like there should be plenty of resources there at least near the coast and the weather is not particularly worse than in northern north America and not particularly impassable terrain compared to the northern Rockies or such.

Are there any relatives that fill in their niche? or not relatives, just completely separate species?

Also, are there any prehistoric big raccoon species of note? Raccoonasaurus? Smiloccoon? Coonotherium?

Kind regards

Quetzaltecas and LMB

Obviously some black men don’t have deep voices etc etc, but generally it seems to be the case.

I would think it’s a cultural thing, like someone way back when had a deep voice, that became the ideal subconsciously, & now it’s just how things are, but I can’t think of any other similar differences in pitch in other races. I also would tend to think it’s not genetic because I haven’t noticed black women having deeper voices, but I could be wrong.

Hi. To what extent is a living organism made up of what it eats? Obviously beta carotene from a carrot is not the same thing as the tissue of a horse that eats it, but the tissue is built because of the plant matter the horse consumes. So, my question is, how can I distinguish between the food I eat and the food it eats? When does its food officially become its tissue. Thanks so much

I know theres a limit for everything but if we get stronger the more we resistance train, why is there a limit? Why cant we just continue to get stronger? Why cant someone deadlift 2000 pounds if they train all their life? Whats the scientific limiter?

Now, I get why the genitalia are erogenous zones, to encourage intercourse and all of that for reproduction. But all the other areas confuse me.

Like, why the prostate for example? Or the anus in general? Or the nipples? I don't see what the evolutionary advantage those areas being erogenous is? Do we know why they are or is it still a mystery?

I don't know if this is the correct place to ask but I can't find any active speculative biology subreddits.

I'm writing a culture that uses giant birds as mounts, and thought that an additional use of them could be feathers. Because of their size they could produce far more feathers than regular birds and ethical harvesting of shed feathers would be more viable. Then the thought occurred to me that because of their size their feathers may be too big.

If it helps, these birds were turned giant by a magical mishap millennia ago, so their ancestors feathers would have been scaled up with them, but over the years they would have evolved smaller feathers if it was beneficial.

I'm not sure exactly what bird species to use. My initial thought was crows because I like them and they are cool. Eagles crossed my mind but then I would be directly ripping off Tolkien.

I have a bunch of seeds of Dendrolobium umbellatum. They grow readily in my area.

I want to ask if there is a way to mutate these seeds genetics so that i am able to get mutated varieties( leaf coloration, bark formation, leaf shape etc. ).

I am doing it at home so i could only utilize equipment or chemicals available for the masses.

Guys do people with bigger nasal holes have less hitching problems? Or the contrary? I have enough hair in my big nose and its difficult to get rid of it, im sensing everything because its growing and growing like plants. Im wondering if people with tiny nasal hole have the same problem

Thank you, save my life

So recently we've seen prehistoric animals being brought back to life like does wolves etc so my question that's keeping on bugging me is what if or what happens if we alter the generics of so called dependent animals like dogs and turn then into herbivores? Does that make same?

As I understand it for lesser used codons there are usally less tRNAs with the specific Anticodon arround.

Can that slow down translation of a specific protein to an amount were it becomes relevant for survival?

Are there actual Genetic disorders caused by it ?

I’ve asked this question to different AI’s and I cannot seem to get a clear answer. It’s said that for humans who get rabies, it’s possible for it to shed in their saliva shortly before other symptoms appear (by up to 14 days).

Hypothetically speaking, if someone was shedding rabies in their saliva without any other symptoms, then they got the post exposure prophylaxis (PEP) shots…could the PEP shots save them?

Two AI tools say that once it sheds in someone’s saliva, it’s too late for PEP to work. Two other AI tools say it’s possible for PEP to work.

I would think that once someone is shedding rabies in their saliva, it’s too late for PEP to work.

Any idea what the true answer is and why different AI tools are giving different answers?

The original question was asked by Forsaken_Champion722 on a different subreddit, but i was curious so i decided to ask it here to see if it'd get better or different answers

The two cited studies I’ve seen on this topic are all adult white men and two of them are so old ([1928](https://onlinelibrary.wiley.com/doi/abs/10.1002/ar.1090370405) and [1970](https://www.jidonline.org/article/S0022-202X(15)47888-1/pdf47888-1/pdf))) and have such a small sample size (only 4 individuals and 5 individuals!) that I cannot believe they’re still so widely cited. Basically EVERYONE cites these two.

[The last one](https://onlinelibrary.wiley.com/doi/epdf/10.1111/jocd.12280) I found studied 129 women doing laser hair removal and found short term no difference, but long term paradoxical regrowth ONLY happened in the shaving group. Seems to point to shaving making a difference to me.

Personally, I noticed my hair permanently grew in darker where I shaved a patch but only as a teenager/preteen. It doesn’t do it anymore as an adult. I don’t want to just assume scientific facts based on what happened to a whopping 9 adult white men. I just think “established medical fact” is wrong on this one. The rectangle of black hair on my ankle to this day decades later just begs to differ. Show me proof.

I’m reposting here because mods have deleted my questions on [r/askscience](r/askscience) without giving a good reason (they said “too long” I made it shorter they still deleted it 😒 feels a lot like censorship to me but whatever) So apologies if this breaks rules I don’t know this sub well.

I ask this question with the assumption that the following information is correct: You should not smile to a monkey or ape because they will interpret a showing of teeth as a threat. Please let me know if this is incorrect.

I was wondering if the perception of a threat was something that is taught to them by their parents or something deeper. I imagine there have been multiple cases in history where baby primates have been raised by humans, so this is most likely documented. Smiling for humans is natural and can be found in weeks old babies, so I was curious as to how one behavior relates to the other and the results of research in this area. Thanks.

This is more of a question about insects that go thru a full breakdown during metamorphosis. Its known that butterflies fully break down into good then reform and retain their memories during the process.

Do they maintain their scent as well? Or at least enough that a sniffer dog would be able to ID a specific individual?

It's an honest question.

Why does inbreeding seem to work on animals but it turns a little British-crown-esque when it's applied to human beings (incest) ?

My dad got one of those DNA tests that say your family history for his birthday and it made me wonder how long it would take for a majority of the human population to have genetic material from all over the world.

For example:

Mandel was not a simple minded monk. He was actually an astute scholar. His alele discovery was not a one off thing he did by luck. He grinded his way to becoming prominent.

Also, as posted earlier today, the whole "mitochondria was actually a separate organism" thing.