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Sub-Fields of Biology

  1. Aug 26, 2012 #1
    I'm thinking about majoring in bio at college next year; however, I was curious about what kind of sub specialties exist out there, beyond undergrad education. I see on the forum all the time, people talking about going into high energy physics, or condensed matter physics, or field optics, or particle physics- you get the picture. My question is, what do these equate to in the field of biology? What kind of specialised or deeply intricate areas exist in biological fields? I've heard of cellular and molecular bio for instance, but beyond that, all I know of biology is- biology. I don't hear it referred to in the same way as these physics areas go. Granted, this is PHYSICS forums, but if anyone who may be a grad student, or PhD, who knows of a wide field of opportunities could shed some light on the subject, it'd be greatly appreciated.
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  3. Aug 26, 2012 #2


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    There are a couple of ways you could classify the subfield of biology. One way to do this is by scale (i.e the size of things one studies). Molecular biologists study life at the atomic and molecular scale, studying how the proteins and other types of molecules inside the cell function. Systems biologists study how collections of molecules (e.g. in singaling pathways or metabolic pathways) function together. Cell biologists study life at the cellular level. They are concerned at looking at an individual cell and how the various processes of the cell work. Microbiologists study small organisms such as bacteria and viruses. Organismal biologists (e.g. zoologists and botanists) study entire multicellular organisms. Population biologist and ecologists study the interactions between groups of organisms and their interaction with their environment.

    One can also classify biologists by the different fields with which they intersect. Biochemists and chemical biologists study the chemical processes of life. Biophysicists study the physics of biological systems and often bring new tools from physics to the study of biology. Biostatisticians apply their knowledge of statistics to biological and medical studies.

    Finally one can also classify biologists by the questions they study. Neuroscientists and neurobiologists are concerned with how the brain works. Evolutionary biologists study how evolution works. Developmental biologists study how organisms grow from a fertilized egg into an adult.

    Of course, these classifications are rough, so none of these are exclusive categories and many categories overlap significantly. I'm also probably missing some categories, but hopefully this list gives you some idea of the different types of biology research being done.
  4. Aug 26, 2012 #3
    Thank you for your reply! That info does help. I think molecular and system biology sound really interesting. I may look into those areas a little more.
  5. Aug 26, 2012 #4
    I think you can roughly split things into quantitative and non-quantitative, that is, how much math, programming and theoretical models do they use? How many physical measurement tools and manipulations they use, as opposed to letting the cell do its thing or manipulating the cell with biological signals.

    And then, you can split further into "big systems" and "small systems". Some fields are highly quantitative because they're physical science (computer science, chemistry and physics) ways of looking at biological systems, ranging from molecules to ecosystems. Other fields are more qualitative, again looking from molecules to ecosystems.

    Quantitative Biology:

    Molecular Biophysics/Physical Biochemistry - Single molecular level
    Computational Genetics - Molecular collection level
    Systems Biology - Cell level
    Biomedical Engineering - Tissue to Organism level
    Computational Ecology - Ecosystem level

    Traditional Biology:

    Molecular Biology/Biochemistry - Single molecule Level
    Genetics - Molecular collection level
    Cell Biology - Cell level
    Physiology - Tissue to Organism level
    Ecology and Evolutionary Biology - Ecosystem level
  6. Aug 27, 2012 #5


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    And mostly you will at most do MORE of one of these things than another but most work and study will have to involve them all.
  7. Aug 27, 2012 #6
    Thanks for all the replies!

    So in quantitative biology, would you consider it to some degree to be more abstract than traditional biology? Based a lot more on mathematical concepts and models? And would the molecular biophysics involve stuff like neural signaling or would those be considered systems biology?
  8. Aug 27, 2012 #7


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    If by neural signalling, you mean how different neurons in a neural circuit cooperate to regulate certain behaviors or processes, this probably falls more under systems neuroscience or computational neuroscience than molecular biophysics. Of course, there are some molecular biophysicists investigating questions in this area, so as people have said, the categorization of research in biology is a bit fuzzy.
  9. Aug 27, 2012 #8
    Concur on the fuzziness of categorization. For example, ecology and evolutionary biology (above listed as "Traditional Biology") has often tremendously benefited from quantitative and mathematical approaches in its history. Some of the major names in the field were originally trained as mathematicians, physical scientists, or engineers.

    And yeah - if you're doing interesting work, you'll almost inevitably have to do a bit of nearly everything, sooner or later.
  10. Aug 28, 2012 #9
    If you're talking about applications remember one of the biggest applications of biology nowadays (and perhaps has been and will be forever) is in the field of medicine. So if you are thinking of majoring in biology then you may want to look at drug design or studying about diseases. Not only are these fields really cool but they also are very lucrative financially.


    I just recommended these two sub-fields of biology since I know them best but you're more than welcome to check out other fields like neuroscience etc.
  11. Aug 28, 2012 #10
    pharmaceuticals is almost entirely chemistry and chemical engineering. There's very little biology in it. You just need to know stuff like what a cell is and whats the difference between bacterial and human cells.

    On the other hand, traditional biologists have very little training in the critical questions of pharmaceuticals today - separation processes, quality control, delivery, stability and formulations, etc.

    Even in "biological" questions like protein structure elucidation, chemists do that. How much do biologists know about crystallization processes? NMR? X-ray diffraction? Optical spectroscopy? Computational chemistry?
  12. Aug 28, 2012 #11


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    Unless your attempt at developing a drug is basically trial and error any biomedical science has to involve biologists (biochem, mol med, biomaterial etc) in their research group.
    What do you mean by traditional biologists? Any not involved in biomedical research wouldn't need to know these things (but may have covered it in their time at university) and those that are will know them to the extent they need to up to and including all of these things.
    I know biologists who specialise in these things. It's important to remember that biology is a huge field, from anatomists to zoologists. This is why for application, especially in biomedical science, multidisciplinary teams are formed.
  13. Aug 28, 2012 #12
    I greatly apologize for my lack of experience, but when I worked in a pharmaceutical company, not a single person was a biologist; everyone was a chemist, chemical engineer or MBA.

    Our main line of business was in new formulations of existing drugs, better delivery methods and contract services, not discovery of active chemical agents. It was a small company, so maybe this is the problem. However, this goes to show that biologists may have limited employment, because small companies aren't really able to afford biologists to do the drug discovery.
  14. Aug 28, 2012 #13
    Any physics related to chemistry has a lot to do with physics. Condensed matter physics, thermodynamics and statistical physics are closely related to the theories of biology. The laboratory experiments often, if not usually, involve analytical chemistry. So many experiments in biology use optics and spectroscopy.
    Modern biology is often just chemistry of complex systems. Much of physics is the chemistry of simple systems. There is no understanding the complex systems without understanding the simple systems. To be a good biologist these days, you have to be a good chemist. To be a good chemist, you have to be a good physicist.
    There are a few topics in physics, not closely related to chemistry, that can be helpful in biology.
    Classical mechanics are also useful in comparative anatomy. Although classical mechanics isn't really important in chemistry, it generally governs the anatomy of an organism. Many introductory textbooks in comparative anatomy start with scaling laws. Which is classical physics. Thermodynamics is important in understanding ecosystems. You have to understand heat. As seen in this forum, heat is more complicated then the public generally understands. So pay attention to heat.
    High energy physics has almost no use in biology. This includes most particle physics. General relativity and cosmology have almost no use in biology. Special relativity is important only because of the role it plays in optics and radiation physics. However, the details of special relativity are not important. Nuclear physics up to nuclear decay is important, but not farther. You have to know about radioactive decay to understand experiments with tracers and geological dating. However, you don't have to know about isospin.
    Quantum mechanics is important with regard to physical chemistry. Therefore, it is important in biology. However, quantum entanglement is not important yet in biology. If entanglement gets into biology, it will enter through some chemistry methods.
    Particle accelerators are now being used in some chemistry experiments. Therefore, they will be used in biology experiments. However, this is part of the biochemistry topic. All sorts of physics creeps into biology. However, they generally creep in through the chemistry door.
    Analytical chemistry is very important in biology. However, most of the methods used by analytical chemists were actually developed by physicists. Although the "wet chemist" had his or her day, spectroscopic methods now dominate analytical chemistry. However, analytical chemistry is very quantitative. So you have to understand the physics in a quantitative way.
    Mathematics is important. Calculus is used in many physical calculations. Computers are very important in biology. So computer programming and numerical mathematics is useful. However, mathematics also gets into biology via the chemistry route.
    To understand analytical chemistry, you have to understand physics. There are a lot of physical principles used in analytical chemistry.
    If you are interested in biology, take chemistry as early as possible. However, introductory physics helps one with the chemistry. I would even suggest taking chemistry and physics together, but lighten the load with other courses. I would say that one physics course, one chemistry course and one English essay course would be a fine introduction to biology! If you take the chemistry and physics first, the introductory biology would be easier.
    English essay is the most important subject and the hardest. Take it first. Understanding physics means understanding English. Even physics must take a back seat to writing. Literature not so much. However, literature is important in defining one as a person.
    Psychology and sociology won't be important for biology. All the important psychology is done by physicists. I have several books on image analysis that would blow away Jung's gestalt.
    The advanced physics courses are not that useful for biology. But advanced here means junior and senior level physics.
    I have certain biases. So I my background may be helpful here. I have worked in physics and biology. So I have some experience.
    I am a retired physicist. My PhD was in lasers, spectroscopy and solid state physics. However, most of the work that I have done afterwords had to do with biodetection.
    My best work was developing a sensitive method of detecting bacterial endospores. It used fluorescence. I use fluorescence, absorption and Raman scattering for all sorts of biology techniques. I also used quantum mechanics as related to shot noise. Again, shot noise is a limitation of spectroscopy. I was really refining some chemistry methods.
    I understand some chemistry better than some chemists. The physics helped me understand the chemistry. So it helped me get into biology.
    My current hobby is fossil collecting and natural history. So I know something about paleontology and evolution. Some of my physics background has been useful there. However, the reason that it is useful is that it helps me understand chemistry. The structural analysis of dinosaurs often uses classical mechanics. The radioactive dating methods of course involve physics and geochemistry. These help me understand what I am looking at.
    General relativity doesn't help me understand fossils. General relativity is important for certain things. It is interesting. I learned a little bit of GR. However, living things don't operate on the size scale where general relativity is important. Same for high energy particle physics.
  15. Aug 28, 2012 #14
    To Darwin123, thank you very much for such an in depth reply! It definitely gave me a clearer understanding and greater interest in the opportunities in the field. I'm a senior in high school right now, but I have taken biology, AP biology 2, chemistry, AP chemistry 2, physics, and I'm now in AP physics 2. In addition, I've taken a couple algebras, geometry, trig (pre cal) and now I'm in AP calculus and AP statistics. So I feel like I have a decent background and prep for college, as you mentioned gaining knowledge in chemistry and physics to understand biology. I've also taken several AP english courses, such as language last year, which is a rhetoric based class supposed to be comparable to the composition 1 class in college, and I am taking AP literature this year. English classes, and writing overall, is something I really enjoy so I'll definitely plan on taking writing courses in college. I will look into doubling up in chem and physics in my freshman year, like you said, and hopefully build a strong foundation for biology.
    Thanks again for all your info and advice!
  16. Aug 28, 2012 #15
    In practice, knowing chemistry and chemical engineering is more useful than knowing physics for biological questions. You don't need to know the covariant formalism for EM or tensor analysis, for instance (which are indeed some of the things you need to study in physics) to do the thermodynamics, quantum mechanics and materials science that's in biology.

    You need to know the physics that most chemists do but not much more. A 1 year introduction to mechanics and electromagnetism is good enough for many purposes, add an upper division classical mechanics class and you'll be great (it seriously has uses in spectroscopy and computational chemistry).

    You'll need to know the math which is standard: calculus, multivariable calculus, linear algebra, differential equations and statistics.

    What is most important will be your actual chemistry/chemical engineering classes: quantum chemistry, thermodynamics, statistical mechanics, chemical kinetics, heat and mass transfer (for engineers), chemical biology lab and analytical chemistry (for chemists).

    I'm just warning you, an actual degree in biology is not that good for going into biological research. Its good for going into medical school. I might be biased, but I had alot of friends who did biology, and all were premeds; if they didn't get into med school, they had zero chance of getting a job in industry and instead worked retail.
  17. Aug 30, 2012 #16
    Thanks for the info. I actually am intending to go to med school. My ultimate dream is to be a neurosurgeon, or neurophysiologist. I'm obsessed with the science of the nervous system- I think it's absolutely intriguing and I would like to go into that branch of medicine if possible. On the other hand, I also have a great interest and overall curiosity of biological/chemical/physical research of the molecular level (and atomic for that matter). So while I would say med school is the goal I'm striving towards, I want to be aware of the various fields and opportunities of biology and how they can intersect with other disciplines, rather than just be another hollow pre-med student who's doing what he needs to do to get accepted into med school (which is why I started this forum). Thank you for the advice- I'll be sure to keep my horizons open in case the med school plan falls through because the last thing I'd want to do is work in retail! haha
  18. Aug 31, 2012 #17
    I suggest biomedical engineering for your interests, if your university offers it. It is much more related to neuroscience than most other fields. However it will be a pretty hard major.
  19. Sep 2, 2012 #18
    Thanks for your suggestion. I checked that out, and the university I plan to go to (Texas A&M) offers biomedical engineering in the enginnering department, but also offers an undergrad biomedical science degree which is technically part of the veterinary school. I've heard it was a difficult major as well, but I've never really heard of it for undergrad. Do you think that might be good to look into since I don't really intend to go into engineering, or would you still say engineering would be the better major? It also looks like they offer a neuroscience minor to the regular biology degree.
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