Dinnertime Sci Comm (Part 1)

If you are part of the online scientific blogging and/or tweeting community, you have probably heard of #upgoerfive. This was an exercise inspired by an xkcd illustration of a rocket, labeled using only the 1000 most common words in the English language. Scientists challenged each other to describe research programs or scientific concepts in the same way (there’s even a handy text editor!). I heard about it over on Dynamic Ecology, and had to give it a shot.

upgoer5My #upgoerfive attempt at explaining my research system

OK, so that’s pretty silly, and I had fun doing it. But, is it actually a useful exercise in scientific communication? There is a great discussion of this question in the comments of the Dynamic Ecology post I linked above. I do see the entertainment value in this exercise, but truly, I could probably use the word “salamander” and most folks would know what I was talking about (and if not, I would offer to get them out in the woods! STAT!).


So, inspired by thinking about all of this (and by having this brand new blogging platform!), I decided to attempt to “level up” my explanation above. My imaginary audience is a group of table-mates at a dinner party. [Editor’s note: Table-mates who are exceedingly tolerant of what turned out to be a rather long explanation.] They are smart people, but they’re not biologists. They may not even know we have salamanders in Michigan (THE HORROR). If I start throwing around terms like “tetraploidy” and “kleptogenesis,” they may suddenly find themselves “having to go make a call, it was so nice chatting, take care hmm?”

I’m going to divide this exercise into two parts, since my research falls into two overlapping but distinct areas. Part 1 (you’re reading it!) will focus on the all-female salamanders that I described above, while Part 2 will describe more applied, conservation-related work (I’ll link it here once it’s posted). I’d love feedback on this exercise, especially from my non-biologist friends and family. Have I managed to avoid jargon? Will you hang out with me at the dinner party?

beerDon’t make me drink this beer alone

I’d also love to read about what other people are up to… tweet it up with #DinnertimeSciComm. And if you’re in the U.K., get me some of that beer please and thank you. 🙂

Why do we care about these crazy all-female salamanders???

Everyone is interested in sex, and evolutionary biologists are no exception. The fact that most animals reproduce sexually is actually something of an evolutionary mystery. Animals that can reproduce asexually – think cloning – should actually have a numerical advantage. With cloning, every individual can produce offspring directly (rather than requiring a male and a female to make a kid). Plus, a clone-mom gets to pass on 100% of her genes, whereas a sexual reproducer only passes on half! Passing on genes is the name of the game in evolution… so why aren’t clonal animals more common?

One possible explanation is that populations of clones lack genetic variation. If the environment changes in some way, those clonal animals are more likely to go extinct. If a new disease wipes one of them out, it’s going to wipe all of them out, because they are all genetically the same. Sexual reproduction “shuffles the deck” every generation, and this increased variation may help populations survive things like new diseases, climatic shifts, or other environmental changes.

It’s hard to really directly figure out the costs and benefits associated with sexual reproduction. We usually have nothing to compare, because most animals just reproduce sexually. But lucky for me, there are some really weird salamanders around here that break all the reproduction rules. We call them “unisexuals,” because there is only one sex – they are all female. To reproduce, they mate with males of other species of salamanders. Most of the time, despite mating, they actually just reproduce asexually; the dad salamander’s genes do not get included in the offspring. But that’s only most of the time. There are also babies produced that DO have dad’s genome added in. So this means if the mom had two sets of chromosomes (like you and I do), the offspring might end up with three sets – and this somehow works just fine for these salamanders. In fact, the vast majority of them are walking around with three full sets of chromosomes!

2015-03-26 11.05.36Three salamanders, nine sets of chromosomes

This means that these salamanders are able to reproduce both asexually and sexually, which is very strange for a vertebrate animal. One of the big questions I’m interested in is… WHY? Are there certain times or environmental conditions when it’s better to be asexual, and other conditions where adding dad’s genome is the best bet? So far we don’t have solid answers to these questions. We know that adding the male’s genome is more common at warmer temperatures. We also have some early results suggesting that females are more likely to add the genome if the male is from their same pond, versus a more distant pond. The suggestion that the females may be discriminating against non-local males is intriguing, but we need to do some more experiments to see if these results hold up. Stay tuned for more breeding experiments (and baby salamander pictures) in the spring!

Container 5-14-15 Container 5-b Developing salamander embryos (photos by Bob Winning)


Published by Katy Greenwald

Professor of Biology at Eastern Michigan University

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