Ask MetaFilter questions tagged with biology

It's fun when they are fetching, and agree to see an etching, that you keep at your lily pad...

Jon_Evil — Fri, 11 Dec 2009 23:48:40 -0800

What happens to slimy amphibians during a drought? Do they shrivel up and die? After an extremely long drought in my aunt's area (northern CA), there was an enormous rainfall, enough to fill a few inches up of her pond that had been dried out all summer. Within three days (probably less), she could hear the calls of the Pacific Tree Frog, and found plenty of them in her pond and its surrounding environs.

Where did they come from? Where did they go? If they actually did leave for somewhere else, how did they know how to come back?

Symmetry yrtemmyS

ecorrocio — Mon, 07 Dec 2009 12:25:33 -0800

Evolutionary Biology Filter: Why are we symmetrical? IANAEB, so just wondering why seemingly almost all creatures on earth are generally symmetrical. Two sides - left / right - two arms, two feelers, 3 sets of two legs (insects), two eyes, two flippers etc. I'm sure there are exceptions (plants certainly), but what is it in our collective DNA that precludes three legged, three eyed, one-sided, 7 armed creatures?

the ---- effect

moorooka — Mon, 07 Dec 2009 01:45:30 -0800

What is the name of the effect, in evolutionary biology, whereby acquired behavioral characteristics that lead to reproductive fitness can result in the selection of predispositions toward acquiring these characteristics? I remember learning about it but I forgot the name. It sounds a bit Lamarckian but it's not.

Do vaccines bring you closer to death?

foulowl — Thu, 19 Nov 2009 21:16:09 -0800

Is there a set quota of white blood cells that the human body produces over its lifetime, and if so do routine vaccines (e.g. the flu) tax the immune system enough to significantly shorten the person's lifespan? A while ago I found out that my room mate is, as he put it, "waaaaaaay anti-vaccine." I chalked it up to his occasional wool-headedness and benign (if frustrated) lack of critical thinking, but today he mentioned that he wanted to finish his undergraduate degree in biology sometime in the next couple years.

After dinner I couldn't help myself and asked him, politely, how he squared his science ambitions with his vaccine beliefs. He explained that the human body only creates a limited amount of white blood cells during its lifetime, and vaccines cause the immune system to unnecessarily spend its set quota on a single pathogen (namely, the one being vaccinated against) and thus "make you die quicker."

I kind of nodded and said something like, "Well, at least it's a scientific reason," but that really does not seem right to me. If the human body has a set quota of white blood cells that's honestly so limited that a healthy person is actually at risk of having their life significantly truncated due to routine vaccinations wouldn't medical practitioners screen patients much more thoroughly to prevent unnecessary damage? Plus, isn't one of the reasons to get a vaccine not just for your own health as an individual but the health of everyone around you?

Add in the hypocrisy factors of a) room mate smokes, b) had a serious case of bronchitis in the last six months that c) nearly developed into pneumonia and I am smelling some concentrated bullshit here. (I feel like his immune system wasted more white blood cells fighting off a contracted case of preventable bronchial infection than it would have during a few years of flu vaccines.) Am I right? Is he right?

Does anyone with a background in biology/immunology/medicine have a definitive answer?

How does this microtome work?

12%juicepulp — Fri, 13 Nov 2009 15:20:27 -0800

Has anyone here used a porter-blum mt2 microtome? What do the adjustments do? So there's a microtome that was sitting under a lab bench collecting dust and I decided to see if I could use it for something, but I'm confused by the controls. Specifically, there is a dial on the left side marked "Thickness" that can be set from 0 to 18 but no units are marked. There is also a screw type dial on top of the microtome that also seems to have something to do with section thickness and has measurements in angstroms. What are the units corresponding to the numbers on the left hand dial, and how does adjusting the two dials affect section thickness? Thanks in advance.

My root canal... it tickles?

raztaj — Thu, 12 Nov 2009 18:18:52 -0800

What is this sensation I'm feeling after getting a root canal? I had a root canal on a molar exactly three weeks ago. Some of the alveolar bone between the roots had been lost, but when I went back to the dentist today to have a post put in, the x-ray indicated it was healing extremely well, and showed "significant" bone restoration - (way cool, and yay!).

But every now and then I feel a slight tingly (not painful, not sensitive, not uncomfortable), almost fizzy feeling under the tooth in question. It sort of feels like tiny seltzer bubbles, but the feeling lasts only 1-4 seconds. I don't feel it every day, but when it does happen, it's usually in bursts of a few times an hour. I forgot to ask the dentist about it since I haven't had the feeling for several days, doesn't cause any discomfort, and doesn't appear to be indicative of any post-root canal problems.

What is this sensation? What is causing the fizzy feeling? Might the feeling have something to do with bone growth? Is it even possible to feel bone growth?

Where did I read about three rules determining how the robots run the factory?

Cool Papa Bell — Tue, 03 Nov 2009 14:41:47 -0800

Help me find a half-remembered anecdote about robotics and computing taking a cue from ant- or bee-like, hive-mind biological processes -- a story about a car factory's paint process organized with just three rules. If my memory serves, the rules boiled down to:

1) do something essential -- paint a car a certain color when that specific color is ordered.
2) do something useful -- when you don't have a specific order for a specific color, paint the most popular color, because there will always be a demand for it anyway.
3) do something -- don't ever stop the line; if both rules 1 and 2 fail, just paint another car with whatever color is loaded in the machine, because that's better than stopping the production line.

Where did I read this? Am I remembering the three rules correctly?

I think I was reading something from Kevin Kelly's Out of Control, but I don't think that's it (can't easily find it in the text).

Compare two podcast episodes for similarity?

pwnguin — Tue, 13 Oct 2009 14:15:23 -0800

How can I generate a dotplot of general files? On a few occasions I've seen some graphics that apply bioinformatics dotplots (aka recurrence plots) to general files, to demonstrate things like beat detection in music, or relationships between .dlls. I'd like to use it to identify strongly conserved portions of an audio stream are between two files.

Is there an open source program that takes two files A and B and generates a dotplot visualization of them? Or even better, one that takes two compressed audio files? I can find plenty of genetics related tools, but I'm looking for a more generalized tool, or at least one specialized for audio or video.

Uh...hang on, just give me a minute.

Demogorgon — Mon, 12 Oct 2009 10:34:31 -0800

What is the most important scientific question of our time? I volunteer at an observatory for a local amateur astronomers' society and one of the guests at a recent star party came up and asked, "What do you think is the most important question science has to answer right now?" Obviously, there is no right or wrong answer, but after the party was over a lot of us were still talking about this question and I ended up learning a great deal from my fellow club members that I might otherwise not have.
The next time this question gets asked I want to be prepared to offer a variety of answers from differing fields and opinions. I don't expect to represent every answer as an expert, but I'd like to be able to give a few more examples than I was able to, and then correlate them to some book recommendations from the answers in this thread about introductions to your field.
I also think it is important to frame the question in a way that can be meaningfully answered, i.e. "What is the most important scientific discovery about to be made?" or something like that.
Of course, I had my own answer in mind, but as a relative layperson to that branch of study I had a really hard time articulating why it was so important to "science." Therefore, if you are uniquely affiliated with a specific field that you think will produce a game-changer, feel free to get as technical as you're comfortable doing.

Thanks!

Everybody dies. How do they look?

kbanas — Mon, 12 Oct 2009 07:16:43 -0800

I'm toying with an idea for a short story or maybe a long story or maybe no story, but the idea has led me to a point where I have a question for those of you who have some knowledge about science and biology. Read on, brave adventurer! So, let's say I have a magic button, and I press that button and every single living thing on the planet dies instantly. I understand that the definition of what is "alive" is a subject of some debate for certain corner cases, but since I am not a scientist and I lack the knowledge necessary to carry on an informed debate on the topic, let's just assume that by "alive" I guess I mean that "it is a commonly held belief among people who study such things that this thing is alive."

So, I would think that this would include people, plants, animals, bacteria, and a laundry list of other things I'm not thinking about.

Ok, so we have our magic button and we know what it does.

Let's say I press that button and everything drops dead where it stands. Hooray!

Now, I know that when a person normally dies, there is a process of decay that works to erode the integrity of said corpse over time.

My question is, how would this process be altered by the lack of any other living things existing? It would be my assumption that this would largely apply to bacteria and things that maybe eat away at a body after it is no longer alive?

So, maybe to phrase it a better way....

Let's say I was able to magically visit this now-dead Earth some 20 or 30 years after I had pressed my magic button. If I encountered the body of a person who had dropped dead on the street in Anytown, USA, what is it likely to look like? I assume that perhaps the elements - sun, rain, snow, wind - might have served to work it down to a skeleton regardless of any other living factors. Right? Ok, but let's say a person dropped dead while being largely protected from the elements - like in a house or in an office or something. What is it likely to look like? Would the lack of bacteria and such work to preserve it such that it would look almost freshly dead? Or would it perhaps look mummified?

Maybe you get the idea. I want to visit a dead planet some decades after the "event" - and I'm curious about how I would find the people and animals and such to look. Get it?

Is sauna therapy particularly useful?

mdpatrick — Sat, 03 Oct 2009 16:24:08 -0800

Are the benefits of sauna therapy real? Some family members of mine talk about saunas being useful for "getting out heavy metals." Supposedly, the body sweats them out. I've not found any valid research to this, however. I've seen some studies suggesting potential other effects, however.

There MUST be some way for me to do student research ...

Xere — Mon, 28 Sep 2009 20:23:20 -0800

My college's biological sciences dept has run out of student internship/research positions. The professors have emailed me back, saying that they might have openings in the spring. But I want to do something now. What are my other options? I'm in Los Angeles. The career center doesn't have any external biology, microbiology, biochem internships listed, either. I'm pretty sure I won't be able to get a position at a college I don't attend - after all, their priorities are their own students. Searching online comes up with jobs that requires me to have my bachelor's degree ... which I don't have yet. Am I doomed to have a weak resume?

Is there an easy way to find free, full-length articles that contain biological contingency analysis?

steampowered — Sun, 27 Sep 2009 16:52:23 -0800

Looking for a free resource for articles in biology that contain contingency analysis. I'm a college student and I need to find an article that contains statistical contingency analysis in it to write up a summary on. I have access to JSTOR, EBSCOHost, LexisNexis, and Academic Search Elite, but searching through them is a huge pain. I need *full* articles that contain all of the necessary data of a contingency analysis, but searches result in very general abstracts with little statistical information and that won't cut it for my assignment. I may just be using poor search terms (specifically "contingency analysis" in these various resources), but otherwise I'd have to blindly go through way too many articles, and I'm convinced that I'm not just being lazy. I really need to see the chi-square test statistic, degrees freedom, specific test used, enough information to create a RxC contingency analysis table, etc. I was referred to the free resource PubMed as well, but I had the same experience with that. Any suggestions???

How specific do my interests have to be for grad school?

Dilemma — Thu, 03 Sep 2009 16:10:16 -0800

I'm applying for grad school for a PhD in Integrative & Evolutionary (aka Ecology & Evolutionary) Biology. I don't know exactly what I want to study. How specific do I need to get on my application/statement of purpose? I can narrow my interests down to these general themes: Conservation, Animals, Marine Animals or Primates, Evolution, Biodiversity...

I know that a lot of the grad school admissions process has to do with getting a specific faculty member/members to want you in their lab/s, and I have identified faculty whose research interests me. But when it comes to writing the Statement of Purpose, I can't write about any really specific thing or question that I want to study. Will this hurt my chances of getting accepted?

Should I do neuroscience or psychology?

Anonymous — Tue, 11 Aug 2009 18:30:23 -0800

I want to research somatic disorders (specifically factitious disorder) or, at the very least, work as a psychologist within a medical context, what undergraduate major should I get? I am choosing between a neuroscience major and a regular psychology major. Unfortunately, the neuroscience major doesn't leave enough time for me to take all of the clinical courses that I want to take. However, I feel that it would prepare me much more to research and practice at the confluence of medicine and psychology.

To complicate matters, I have never taken any biological sciences or chemistry at a college level and it has been 7 years since I took them in high school. I don't want to do so poorly that I get kicked out of the major or hurt my chances of going to grad school in clinical psych.

This question is anonymous because my controlling parents follow me on mefi and they don't need to know I am considering graduate school.

Neurologically, what is the difference between being stressed and excited?

lunchbox — Sun, 02 Aug 2009 16:23:46 -0800

Neurologically, what is the difference between being stressed and excited? Because stress/anxiety and excitement/thrill feel so different, I would expect them to be physiologically very different. Yet from the reading I've done, they appear to involve very similar neurotransmitters and body systems (HPA axis activation, adrenaline release, etc). What are the specific physiological differences between the two?

Help me identify this... thing.

Paul KC — Thu, 30 Jul 2009 12:59:46 -0800

What is this strange organic thing that washed up on the lake shore at my parents house? My parents live on a lake in northern Idaho and have had several of these wash up this summer and several have washed up on shore at the neighbors' house as well. This is the first time any of them have seen them.

The one in the pictures was about 30 inches long and 5 or 6 inches in diameter. It smelled almost like rotting fruit, and could be smelled from 20 or 30 feet away.

Here is a picture of it up close.

And here is a picture of the inside of it.

Intellectual histories of the natural sciences?

shivohum — Sun, 12 Jul 2009 12:18:03 -0800

Any recommendations for books giving a general history of any of the natural sciences, with a particular attention to how the great biologists, botanists, and zoologists, etc. approached problems of classification and conceptualization of their phenomena (e.g. like how Linnaeus came up with his taxonomy)? Not looking for great technical detail so much as how these scientists thought and responded to each others' thoughts.

Getting our rocks off for four billion years

shakespeherian — Sat, 11 Jul 2009 12:32:51 -0800

Can anyone recommend a good book about the evolution of sexual reproduction? I'm interested in the basic physiological explanation (how did single-cell organisms lead to sexually binary species, etc), big-picture explanations (why is sexual reproduction advantageous as opposed to asexual reproduction, etc), and maybe a good overview of the differing sexual characteristics of disparate species the world over (four-headed echidna penises, etc). Caveat: I have hardly any scientific background, so too-technical books aren't great, although I am a pretty fast learner if the book makes a decent effort (I made it through DFW's Everything and More despite not having done any math since high school calculus).

I've seen this question but I'm more interested in getting a whole dang book than just receiving answers to particular questions.

Did Richard Feynman have a brother?

SamuelBowman — Tue, 30 Jun 2009 03:09:42 -0800

I'd like to learn about biology. Can you recommend some books to get me started? I've only done secondary school (ie, high school) biology and my background is in history, so I'm fairly ignorant of the subject, but I've always been interested in it.

What I'm looking for are recommendations for books that will introduce me to the topic – my specific interests are in zoology and evolution, so advice there would be great, but I'd like a primer on the whole field as well.

I really enjoyed The Selfish Gene, but more because of its discussions of animal behaviour than genetics, so that might show you what I'm looking for. It would also help if the book(s) are enjoyable to read – a textbook might have some great information in it but be horrible to read. What I want is to be able to think like a biologist, understand what it is that's going on in the field today, and learn about the how (and why) living things work.

TLRs in all cells or just professional APCs?

metaBugs — Wed, 24 Jun 2009 04:59:10 -0800

MolecularBiologyFilter: Embarrassingly easy question for any immunologists out there: are Toll-like receptors (or other pathogen recognition receptors) only expressed in professional antigen presenting cells (DCs, macrophages etc), or are they in e.g. epithelial cells too? Some papers I've read imply that TLRs are only expressed in in antigen presenting cells like dentritic cells, macrophages etc. and maybe some effectors like NKs. But while the small mountain of papers I've skimmed -- or even my ageing immunology textbook -- give reams of really lovely detail about their sequences, structures and mechanisms, I can't find anything that explicitly tells me where the darn things are found.

I get the strong impression that it's one of those "too obvious to bother mentioning" things, but I don't have a tame immunologist nearby today. Can anyone help me out?

Background for curious non-biologists:
You've probably heard of "antibodies", molecules that your body produces in huge variety to recognise anything "non-self" like bacteria, viruses and in my case pollen, making every summer a living hell. Every person (indeed, every mammal) has different set of antibodies because we make them almost from scratch, in a process that biologists call random but a mathematician might call chaotic. By making them at random, it means that the immune system is generating antibodies against stuff it hasn't encountered yet; by sheer luck, a tiny proportion of them will probably be about right to recognise an infection you've never had before and nuke it before you even know you're ill. The immune system is awesome.

My question is about "Toll-like receptors." These are similar to antibodies in purpose, but we all express roughly the same ones. Unlike antibodies, TLRs' structures are fixed, encoded by our genes. Their job is to recognise really common hallmarks of infection, e.g. lipopolysaccharides found in all bacteria's outer membranes, or unmethylated CpG motifs, which are really typical of virus DNA but not our own. These TLRs are often the earliest things that get triggered at the start of an immune response (they're part of the "innate" response) and lead to ramping up the activity of the more powerful and adaptive response that involves the more clever stuff like antibodies and/or killer cells specifically customised to target the new infection (the slower but more powerful "adaptive" response).

I want to know if they're in all your cells (so a random lung cell that gets infected with, say, a coronavirus will trigger an internal response to help stop the infection before it starts and thus prevent your cold) or if they're only in the cells that roam your body deliberately swallowing everything they can, looking for new pathogens.

Oh, and the "Toll" in TLR apparently means "Wow!" in German, after what the woman who discovered them shouted when she first saw her experiment's results.

Yes, but if we were birds, would traffic STILL be backed up for miles?

zarq — Mon, 08 Jun 2009 13:30:54 -0800

Is there a scientific explanation for rubbernecking beyond "simple curiosity"? Are we predisposed as a species to run towards danger? I was re-reading David Brin's Uplift War, and a character mentions that this is one way in which primates are unusual compared to other animals. Is this is an accurate assessment? Do other animals do so? Have there been any sociobiological studies of various animal orders or species which support or refute the concept?

Island of Dr. More-asses....

ladypants — Mon, 18 May 2009 11:31:06 -0800

How can I make a monkey with four asses? Hypothetically of course.

I'm studying for my developmental biology final and one of the study questions asks how one could conceivably create web-footed mice as designer pets. (One answer involves preventing inter-digital cell death by inhibiting bone morphogenic protein (BMP) signaling. One could do this with strategically placed beads soaked soaked in Gremlin protein.)

So the natural extension of this question is: what if I want to make designer pets with webbed feet and four asses? How could I accomplish this?

In terms of what constitutes an ass: I am less interested in anuses than buttocks. Four sets of round bilaterally symmetrical buttock muscles coated in subcutaneous fat would be the gold standard. And they can be anywhere on the organism although dorsal positioning seems more traditional than ventral.

Don't worry, I'm not actually making any little monsters. I am curious about non-limb muscle development and I'm having trouble finding information about it. So I'm interested in any ideas on how the classic four-assed-monkey could be made. Any information on the developmental regulation of musculature would be helpful as well as any info on butt-region related signaling.

What have been the significant advances in biology since 1993?

Joe Beese — Fri, 15 May 2009 17:29:00 -0800

What have been the significant advances in biology since 1993? One of my prized books is the 3rd Edition of Neil A. Campbell's Biology published in 1993. What are the most important things known in the field today that were not known then?

(For extra credit: If Dr. Campbell were still with us to prepare a 2009 edition covering the same ground, what percentage of scientifically new content might it be expected to have?)

I want to play with your octopus (literally)

Cambrian_Sea — Thu, 07 May 2009 13:25:17 -0800

I am a biology student at the University of Utah specializing in animal behavior, and I have a particular interest in cephalopods (squid, octopi, cuttlefish.) Everything I know about them is from reading, and I would love to have the opportunity to observe one in real life, and perhaps even interact with it if that would be possible. Does anyone in the Salt Lake area have a pet octopus or know of one that I might be able to meet?