I am a Professor of Zoology. My research into bacterial genetic recombination asks “Do bacteria have sex?” My free online course "Useful Genetics" starts today. Ask Me Anything!

So do bacteria have sex?

If you define 'sex' as 'maleness and femaleness', or something like 'intercourse', no. If you define it as 'processes that move genes from one cell to another', yes. But to me the most interesting definition is 'a process whose evolutionary job is moving genes', and my (controversial) answer is NO.

Wait, what's the difference between "processes that move genes from one cell to another" and "a process whose evolutionary job is moving genes"?

Ooh, I think we need an analogy here, to clarify the distingtion between function oand effect.. The hemoglobin in your red blood cells has the job of carrying oxygen to your cells - natural selection has acted on it for this function. Hemoblobin also makes your blood red, which lets you blush, makes your lips pink, and makes it easy to see when you've cut yourself. These are effects but not functions of hemoglobin. We can think of them as side effects. In the same way, the processes that move genes between bacteria are side-effects of their real functions (replicating and repairing DNA, moving the genes of viruses and other genetic parasites).

Is there a point where the side effect becomes the primary effect? Like maybe rhodopsin proteins?

For sure, functions can change, and what was once a side-effect can become subject to natural selection. To understand what's really going on in these cases we need to investigate the phenomenon very thoroughly, with an open mind.

Hi Dr. Redfield,

I'm near the end of my PhD, trying to start up a blog to write on a regular basis. Do you have any advice for someone who's trying to establish an online presence in this way? What would you recommend prioritizing?

First decide who your audience is and what you're going to offer them. Latest exciting results in your broad field for the interested public? Critical analysis of results in your narrow field for other scientists?
Once you're writing some posts, use Twitter and comments on related articles to bring attention to your blog. To motivate you to keep going even when readership is lousy, find personal benefits on the blogging -for me it's now it clarifies my own thinking, and how it gives me writing practice.

Thanks for the pointers! Yes, I anticipate motivation being a sticking point, with a couple false starts in the past.

I'm active on Twitter (found this AMA from there!) but I hadn't thought too much about commenting on other blogs. How do you walk that line without being brazenly self-promotional?

You can briefly comment on some aspect of the post, and then describe what your post adds to the discussion. As long as you're not trying to build your reputation by saying only what everyone else is saying, the readers will recognize that you're adding value. Bottom line: Your goal can't just be to establish an online presence - you must want to build a reputation for good work.

Are GMO foods bad?

Bad for the health of people who eat them? Definitely not. GMO foods are much more thoroughly tested than 'conventionally bred' foods, and any that make it to market have passed all the tests.

Bad for the farmers who grow them? Again, definitely not. In India, the formerly catastrophic incidence of pesticide poisoning in cotton farmers has plummeted since they began using BT-cotton. The main reason the farmers pay the extra cost for BT-cotton seeds is the saving in pesticide costs. Bad for the environment: This is an area where we do need more data.

You know foods generated by ems and uv mutagenesis are not classified as GMOs? No one ever mentions that in their replies.

Yes, conventional plant breeding uses old-fashioned tools to generating random mutations throughout the plant's genome, and then sells us the varieties whose mutation-mixture makes them attractive to consumers. Sometimes they label them as 'heritage varieties'!

This might sound kind of pedantic, but can I ask why you identify yourself as a professor of zoology? My understanding was that zoology referred to the study of animals (i.e. metazoans). Aren't you more of a geneticist or microbiologist?

That's easy - the Department of Zoology pays my salary! But the study of Zoology is now very broad, including a wide range of molecular biologists and cell biologists and theoreticians, who never involve animals in their research.

Do you think Angelina Jolie made the right decision based on her genetic risk?

These decisions are very personal, so we can never say what was 'right'. But if I had been in her place (carrying a BRCA gene version that creates a very high risk of breast cancer) I would have made the same decision. The genetic tests are very reliable, and the cancer-risk data is very strong. Worse, we don't know of any 'lifestyle' changes that would have make a big difference in risk of breast cancer.

Hi Dr. Redfield, I actually had Biol 234 with you back in winter 2011. This is sort of a follow up of the question to do bacteria have sex, when people ask if bacteria have sex are they mostly referring to the process of conjugation, and the transfer of plasmid DNA between bacteria?

Also how common have you found the 'sexual' transfer in bacteria?

(I'll ignore the word 'sexual'.) When we look at bacterial genomes we find many genes that clearly have been transferred from another species at some time in the past 1,000,000,000 years or so. But it's very hard to estimate a rate from such information. Transfers between bacteria of the same species are much more common, but harder to detect. How much of this transfer is due to conjugation? some, for sure, but probably more occurs as side effects of phage infections, and by natural competence for DNA uptake.

This is probably a fairly basic question, but what is your favourite animal, and why?

tardigrades. See Carl Zimmer's latest New York Times article: http://www.nytimes.com/2015/09/08/science/the-tardigrade-water-bear.html?_r=0

Hi Rosie!

The arsenic bacteria saga was a fascinating one to follow, and reinforced for many people that extraordinary claims required extraordinary evidence. It also brought up the topic of the reproduction of scientific results. It's becoming clear that we aren't trying to replicate results as often as we should be. Reproducing research is almost seen as a waste of time (and money), especially since it can be impossible to publish. How do we convince more researchers to dedicate some of their time and money to this cause? How can I (as a grad student) convince my supervisor to let me re-do someone else's work?

At least in molecular biology, most replications aren't done to test if a published result is correct - they're done as controls for follow-on experiments. Only if the control doesn't work repeatedly do the new researchers suspect that the original result might not be reproducible. This is usually fine - if the result is important someone will try to follow it up, and any problems will be revealed.

So tell your supervisor that you want to do a follow-up experiment, and be meticulous in your control experiments!

Hello Prof. Redfield,

I'm just about to start my third year of undergraduate studies in molecular and cellular biology (MCB) and was wondering what areas within MCB you would pursue if you were in my position? What research in MCB do you believe to have the most potential for expansion, and any further advice you wish you had known before starting on your path towards academia?

As a last question, can I ask why you think genetics is taught poorly currently and what can best be done to rectify the situation?

Thanks in advance for you time!

What to study: Study what you personally find most interesting - that's the stuff your brain will pay attention to. If later you discover that something else has become interesting you can always learn it then. Genetics teaching: I used to worry about HOW we teach genetics (our pedagogical methods), but now I think most of the problem is WHAT we teach (the information and skills we want our students to learn).
Few educators seem to put much emphasis on how students are going to use what we teach them, so we waste our time and theirs teaching them outdated skills and ignoring the wealth of new personally relevant genetics.

Hi Dr. Redfield,

I'm staring a zoology course at the university of Sheffield in a week and a half. What advice would you have for a student looking to pursue a career in zoological research? Or do you have any general tips for studying zoology at university level?

Two semi-contradictory pieces of advice: 1. Study what you like best, what you find most interesting and exciting. You'll get the best grades, because your brain will be fully engaged. 2. Study as broadly as you can - learn about lots of different areas that interest you. Being able to put together ideas from different areas will set you apart from the rest.

Hi Rosie! Thanks for creating the online course. It looks great!

My question is: how can we convince UBC to change the "Start an Evolution" motto?

Oh yuck, don't remind me of that awful slogan.
For non-UBC people, "Start an Evolution" is the motto of UBC's giant fund-raising campaign, which has been going on for years. It must have been dreamed up by some advertising people (UBC probably paid them big bucks). I think we are powerless. If we could offer them enough money to pay for some new buildings they might listen to us, but otherwise we're stuck with it.

What's holding back the weaponization of genetics? Where are my supersoldiers riding around on a T-Rex?

Ethics is so tiresome, isn't it!
The truth is that genetic engineering of organisms into weapons is extraordinarily difficult. We can change one gene, but the consequences interact with all the other properties of the organism, and usually our new product functions worse than the original, not better. T-Rex's would probably make terrible weapons. They'd probably be very easy to kill, very difficult to breed, and how could we get them to do what we want rather than what they want?

Thoughts on anti-bacterial cleansers?

I remember a college course where the professor mentioned they were more harmful than helpful. The analogy she gave was our hands have good bacteria that prevents bad bacteria a place to be and anti-bacterial cleaners just kill everything, even "good" bacteria.

Truth?

I'm not very sold on the 'good bacteria' bad bacteria' dichotomy, nor on the whole idea of trying to 'sanitize' our selves or our environment. Your professor was right that these treatments, to the extent that they kill anything, kill indiscriminately, and we have no idea what the consequences are. I think their sales are mainly driven by marketing, not by genuine health benefits.

Hi Dr. Redfield, Im a biology student from the UNAM. I'm interested in zoology and ethology and would like to take a master's degree that relates with these fields. In your oppinion, which unversities offer the best programs?

I'm afraid I don't know at all, because these aren't my fields.

Are there any known elements, besides the encoded trait itself, which promote horizontal gene transfer and have any been identified as more effective than others?

Lots of genetic parasites encode gene transfer machinery. The one we take for granted is the transfer of virus genes, which is how viruses work. The virus DNA or RNA encodes the proteins that form the outer shells of viruses, and the enzymes that pack virus DNA or RNA into these shells. There are other genetic parasites that don't bother packaging their DNA - transposable elements are the best known kind.

If I can follow up on /u/Brenny 's question, I remember the study involved high-tech approaches to answer some questions maybe more easily addressed with simpler techniques. Do you think there is a danger of complicated techniques leading to complacency in experimental design? Are we getting lazy as better machines give us confidence?

Yes, we old fogies certainly think so! We all rely heavily on kits and fancy machines, and often we can't take the time to really learn how they work. That said, in the #arseniclife debacle the researchers used both very simple culturing and DNA work, and very high-tech analyses. The high tech stuff was fine, but their conclusions were led astray because the simple work had been carelessly done!

Hi Dr. Redfield,

I did a presentation about arsenic-gate in my sophomore year at Moscow State, and you're among my role models since then. It's really nice to see you here! Also the course Useful Genetics is a big pleasure so far. So, my question is: do you have, by any chance, a spare place for a new Ph.D. student in your lab?:)

In principle I do have 'places' for PhD students, but unfortunately I have no spare funding to support them while they work! It's become almost as hard to get a grant under the Canadian CIHR system as under the American NIH system, and the Canadian grants are also a lot smaller than the American ones.
Now if you had been awarded a studentship that would support you...

I like the elephants and gorillas at the zoo. Do you get to name them at your zoo ?

Unfortunately most zoology professors don't get to interact professionally with zoos. Even more unfortunately, Vancouver (where I am) doesn't even have a proper zoo!

Unrelated question, but it is an AMA. Just started my undergrad, and I am a bit nervous about failing hard. Any personal tips that helped you be successful in your studies?

Be brave about admitting when you don't understand something, and be assertive about your right to develop a better understanding.

What do you think about Sir David Attenborough?

I don't have a TV or Netflix so all I see is the clips my colleagues post. They're great!