Over the winter break I took three weeks to visit my family and friends in Portland, OR. I think I saw pretty much EVERYONE I usually promise to see on such holiday visits. Usually I have a 50% attrition rate, but by staying for a prolonged period of time I met all my people, rest, and work goals.
However, meeting so many people made me realize how few people knew what I was doing and, more importantly, WHY I was doing it. They were usually not asking about the larger philosophical reasons why I am in Paleontology or a Masters program in Texas (let’s save that for a later post), but why, as a paleontologist, I am studying the skulls of modern lizards. Good question. Let’s get into it.
I am studying Australian agamid lizards (heretofore referred to as ‘AA lizards’), specifically the osteology (skeleton, bones) of these lizards. These lizards are highly variable and some are crazy enough to appear on popular nature shows. If you’ve ever seen a frilled lizard running upright (i.e. Chlamydosaurus kingii) or a spiky lizard that slowly walks and gorges itself on ants (Moloch horridus), you’ve seen one of my study organisms.
Fun fact: Jurassic Park’s Dilophosaurus has more in common with the frill-necked lizard (C. kingii) than the actual reconstruction of the dinosaur. Represent!
Agamids are part of Squamata, the largest living order of reptiles (a group of animals long thought to be the domain of naturalists and 8 year old boys, which is, in fact, a myth). The ancestors of modern agamids differentiated pretty early from the rest of Squamata. Agamids, iguanids, and chameleons form the Order Iguana (appropriately named). Iguanids and chameleons are probably more closely related to each other than to agamids. After that… the picture gets rather hazy.
Like most of the current dominant orders, squamates are thought to diversify during the Jurassic. After this the agamids die off in the Americas when Pangea splits, but they slowly invade Africa, Asia, and, eventually, Australia. Recent genetic analyses1 have shown AA lizards have been in Australia for much longer than their slow invasion would have allowed. Remember that.
Behold, Pangea! If ever there was time for a road trip…
The fossil record? Sparse and mostly jaws, which is actually pretty cool. Agamids and chameleons have teeth that literally fuse to their jaw bones (acrodont dentiton)2
. They literally can’t lose their teeth. Instead, they are worn down gradually and eventually the jaw is used as a cutting surface if no tooth is left. For chameleons, all teeth are irreplaceable, whereas for agamids only the side teeth are irreplaceable and the front teeth are replaced with wear (pleurodont dentition). So, their teeth are pretty cool, but that means most of what is known about the osteology of agamids centers around the jaw (or the ribs, if you are Draco volans, but I digress).
So what is the problem? Currently, most of the work on modern agamids is genetic, which is awesome, but it means there is no way to directly compare what we know about modern agamids with their fossil ancestors (which lack genetic data). Fossil DNA has been sequenced, but only for fossils that were well preserved and only thousands of years old. In other words, the babies of the fossil record. Babies. DNA duplicates and changes easily, which is how evolution can occur, but that means it also easily degrades once death occurs. What paleontologists are mostly left with is bones.
Genetics can overestimate the divergence times of different groups of animals, and accuracy decreases the farther back in time you go. Often, fossils are used to calibrate or check phylogenies, but if no one knows what a fossil agamid would look like… And that’s where I come in!
What I have done so far: collected all osteological characters used to describe agamids, rewritten characters, coded characters on my lovely AA lizard skeletal collection*, and recorded all the weird stuff I’ve noticed along the way.
*skeletal collection not actually mine, but we’ve bonded a bit
Currently: I am running tree analyses, taking pictures through a microscope to definitively record these characters (you’re welcome, five interested people), and writing.
In a few months I will be able to tell you what makes the skeletons of different species of AA lizards unique, what these characters can contribute to a phylogeny, and one of the many critical gaps between the past and the present will be a little smaller. I am adding information not only to the past, but the current state of these lizards, which is becoming more and more critical in our extinction-centric world.
What more do agamids have to offer? That, my friend, will have to wait for a later post…
1. Smirina, Ella M., and Natalia B. Ananjeva. “Growth layers in bones and acrodont teeth of the agamid lizard Laudakia stoliczkana (Blanford, 1875)(Agamidae, Sauria).” Amphibia-Reptilia 28.2 (2007): 193-204.
2.Hugall, Andrew F., and Michael SY Lee. “Molecular claims of Gondwanan age for Australian agamid lizards are untenable.” Molecular biology and evolution21.11 (2004): 2102-2110.
Lately I’ve been thinking about summer paleontology field work. (Field work? Fieldwork? I never know which to use.) The endless Boston winter has called up this nostalgia, because I am tired of the cold and slush. I want to be back out in Oregon’s high desert in the summer, taking painstaking field notes in little yellow Rite in the Rain notebooks, shivering in the cold morning while staring at the pot of water on the camp stove willing it to boil faster dammit I need my tea, hiking through sagebrush or climbing dry riverbeds up the valley, scrambling up crumbly slopes to measure section, holding in my hand an actual fossil that I just found….these are thoughts to get a person through.
I love paleontology field work because it connects me to my research in the most basic way: I am crawling around in the dirt, sometimes with my nose inches off the ground, and finding fossils that no one has ever found before. And they’re fossils that contribute directly to research. The first paleontology project I finished was completely digital: we did some stats on some data that came from other papers and a database. We found some neat things, and I got hooked on how awesome it is to find out something that nobody else knows. But it was pretty far removed from any physical specimens, for me. So the first time I went out in the field, when I got to find real fossils and take notes on them and bring them back with us to go in the museum…that drove home the connection. It brought a very nice sense of continuity to my grasp of paleontology.
I love paleontology field work because I get to go camp and hike with fellow scientists for a week or two, many of whom are my close friends. Better yet we’re in the desert, where my hatred of thermoregulating in the cold is offset by my complete and utter happiness in unreasonable heat. It never fails to amuse me that the hot, dry air sucks the sweat from your skin before you even realize you’re sweating, until you take off your backpack or knee pads and everywhere underneath is soaked. I like feeling badass when, at the end of a long day of work, I hike back to the truck carrying a big sandbag full of matrix from a microfossil site. I like sleeping in a tent. I like cooking dinner on a camp stove and eating for lunch whatever bizarre combination of fruit, nuts, salami, cheese, and tuna-in-a-packet I happen to have packed that day.
I do not love spiders in the pit toilets. I do love my rock hammer.
I love paleontology field work because, I’ll admit it: I really like long car rides. I know that’s a bit weird. But some of my favorite activities are napping, thinking about stuff, reading, and having long conversations with people…all valid choices for long, dusty car rides between field sites, which for us are spread out across much of Oregon.
I love paleontology field work because it’s a major change from the usual computer-centric work I do. Sometimes it’s hard to feel satisfaction and a sense of accomplishment when you’ve been hammering away at the keyboard all day, you know? But there’s no denying that you’ve done a good day’s work when you hike out there and find a bunch of new specimens or track down an old locality, flip a plaster jacket from yesterday’s work, or maybe measure a bunch of stratigraphy and bring back samples from each layer. Bonus points if you’re taking field camp for credit and stay up til 1am lovingly finishing your strat column, cough. Oh, the howls of despair when you mess up one of the lines with your Micron pen…
If summer scheduling allows, I’ll be out doing all these things (except making strat columns in the wee hours!) this July. For now, I suppose there’s nothing to do but glare at the snow-fluff coming down outside my office window and get back to work.
We’ve just returned from our third time at the Society of Vertebrate Paleontology Annual Meeting, and our first as graduate students. What a wonderful, exhausting, exciting experience! SVP is always a great meeting, and it gets more fun every year. The first year or two were much more stressful because we didn’t know many people (more thoughts on conference-going as an undergrad in a future post), so it was nice to relax a little more. This was also the first time we really looked forward to reconnecting with our undergrad friends and mentors, the UO Paleontology crew. It was a bit like an early, very scientific Thanksgiving.
Instead of trying to sum up the whole conference, we’re planning to share a few highlights: our favorite talks and posters, how our presentations went, things we really enjoyed about this year’s venue, and a few bits we think could be improved in the future.
Favorite talks Brianna: It’s tough to choose. One that really impressed me was Paul Koch’s investigation of network structure in Pleistocene megafaunal extinctions. He argued that extinctions have two main components- external factors, which trigger extinction, and internal factors, which are system properties that allow the effects of those triggers to operate. This second component is often overlooked, so he (and coauthors Pires and Guimaraes) set about investigating whether Pleistocene assemblages were in some intrinsic way more likely to collapse. They compared megafaunas from modern Africa and Pleistocene North and South America, looking at networks of relationships between animals. They modeled the probability of two animals interacting as a function of predator-prey body mass ratios. Essentially, the model specified that every time a large predator runs into a prey animal, it’s going to be bad for the prey; every time an animal runs into a conspecific, it’s going to be bad (because intraspecific competition); every time a smaller predator runs into a prey animal larger than itself, nothing happens, and so on.
They then examined the stability of these community matrices and found that modern Africa is no less susceptible to perturbation than the fossil assemblages. However, they did find that the probability of stability decreased with predator richness and increased with the average body mass of the prey. Koch suggested that large predators have a wide diet breadth, increasing connectivity in the web, whereas large prey are more controlled by bottom-up effects (temperature, food availability, etc) and thus decrease connectivity. In a tightly connected web with strong interactions, effects propagate faster, like motion that comes from hitting a tightly stretched sheet of fabric as opposed to a loosely draped one. Pleistocene North America had many large predators (sabertooth cats, cave lions, dire wolves, regular wolves, bears of several sorts…), so perhaps this contributed to the demise of our megafauna. A complex talk with much more nuance in methods and conclusions than I’ve described here, but very cool.
Other talks I really enjoyed: Tseng on skull morphology convergence both within and between bone-crackers and bamboo-eaters, Miller’s investigation of how well a death assemblage captures community ecology of the living assemblage, and Holroyd’s eye-opening talk on identification bias in collections, where she pointed out that specimens can only get studied and published if they are identified. She also quantified the probability of “losing” a specimen via lack of identification.
Kelsey: There were too many mind-expanding talks to cover here, but some of the ones that bent my world a bit (in a good way) were the ones that looked at the historical and identification biases of data sets. Pat Holroyd’s talk was nicely complimented by Matt Mihlbachler’s look at Cope’s rule as a product of historical collection bias. Specifically, brontotheres initially appeared to consistently increase in size throughout the Cenozoic. Matt pointed out that this conclusion was reasonable during Cope’s era, because this is what the available data were saying. However, greater sampling has shown there are multiple lineages that dwarf or just never increase in size over time. Compound this with the multiple migration events between the Americas and Eurasia and you’re looking at a much more complicated, nuanced relationship between the evolution of body size in lineages and time.
This is the vibe I got from many of the phylogenetic and systematic talks as well. It’s as if we are realizing that many of the “ground rules” of paleontology are not as solid as we thought. Now we are looking through the cracks and finding some very interesting mysteries. Perhaps it has always been this way and it’s my own assumptions that are beginning to crack.
Favorite posters Brianna: I think my favorite was Poster #1 on the very first day, by Sadleir and colleagues. It was a reconstruction of body mass and related characteristics in an ornithischian dinosaur where the analysis drew on information from a gastrolith that stayed with the fossil through preservation. From a new CT-scanning algorithm originally designed for distinguishing metal-metal surfaces (led to much clearer imaging of the rock-rock bits, as fossils are!) to an interesting argument for massive tail muscles in this particular dino (perhaps needed to counterbalance gastrolith position, and supported by tail vertebral morphology). Had a great discussion with the author and am really interested to see where that project goes.
I also had a great time getting the poster-talks from current undergrad students in the UO Paleontology group. They were just revving their research engines as Kelsey and I left, and it reminds me of the fun and anxious times we had at our first conference. Plus, they are doing really cool work and I enjoyed hearing detail about their projects for the first time. Warm fuzzies all around.
Kelsey: I’m a sucker for bone histology, so I found myself discussing bone growth and function a great deal. This is a nice connection for me to the dinosaur world. There is an unfortunate schism between the “Mammal People” and “Dino People” (with neoaves falling somewhere in the middle and fish people partying on the side), and it’s easy to stay with your own crew. Hopefully I can find more connections in the future.
I also enjoyed the less-finished project posters, where I could really talk to the presenters about the structure of their future projects and why the label on the y-axis of their graph was missing. We’ve all been there…
Our presentations Brianna: I gave a talk titled, “Identifying isolated postcrania using discriminant analysis.” In plainer language, that’s: “How to use some pretty simple data analysis to figure out what kind of horse/camel/whatever those ankle/toe/hand/foot bones belong to.” You know, the ones that are sitting all unloved in drawers in your museum. This was my first big conference talk, so while I usually do well with public speaking, I was a bit of an adrenaline-rushed mess for the two hours before I spoke. Happily, my nerves settled as soon as I started presenting and the whole thing went very well. My time slot was in the morning session on the first day of the conference and it was great to get the stress out of the way. I got some excellent feedback and ideas after the talk, including some fun new collaborations.
I’m really fond of this work. One bit of it will come out soon as a paper in Palaeo Electronica with my former advisor Edward Davis; I’m currently writing the second paper, which deals more specifically with the stuff I talked about at SVP. Both will get the blog post treatment when finished, but if you’re interested, shoot me an email (bmchorse at fas dot harvard dot edu) and I will happily explain how you, too, can get IDs on your postcranial fossils.
Kelsey: This was year #2 for presenting a poster on osteopathology in Rhinocerotidae, and never have I been more grateful to present an updated study. I’ve been looking at population-level osteopathology in rhinos from 50 mya to the present, a project that has motivated me to learn the intricacies of pathology, bone growth, large mammal evolution, and systematics. Being able to display my constellation of data and questions led to at least six firework moments (what some would call eureka moments) during my two hour poster session. This year I also kept a notepad and pen nearby so I could write every suggestion down. Paper, here I come!
Good things about the meeting!
The welcome reception at the Natural History Museum of Los Angeles County was really, really lovely. Everyone got to wander around the exhibits before eating some impressively tasty food. The dueling T. rex and Triceratops in the main atrium are beautiful, the brand new Dinosaur Hall is spectacular, and Brianna particularly enjoyed some very skeptical looking mammals:
Skeptical striped mammals are not impressed.
What else did the Society do well this year?
They added a family room for the first time, which is an important step in making the meeting more friendly to those of its members traveling with children.
Free wifi for conference attendees. People have been begging SVP for this for years, and still nothing! Heard much unhappiness about this, verbally and online, during the conference this year. We’re pretty sure that offering free wifi would drastically increase the number of people live-blogging and live-tweeting the conference, thus increasing visibility for the Society itself. 3G was only an option for a few people who are from the US, have smartphones, and weren’t worried about a data cap; it’s not good enough. This post has many curated links about live-tweeting and conferences, if you’re interested.
Can you keep the coffee out all morning, please? Remember what we said earlier about sleepy scientists? You already bring it out at 7:30am and again at 10am – just leave it out til lunchtime. Or better yet, leave it out until the poster session starts at 4:15. It’s one of those keep everyone happy, keep everyone awake things. We are such sad pandas when we straggle down at 8:30 and the coffee/tea has been whisked away.
Give some serious consideration to venue with respect to pricing. We acknowledge there are probably many, many interests to balance when selecting a conference hotel, but please add this one. SVP 2013 was in the middle of the financial district in Los Angeles, meaning a very expensive hotel and limited (+ expensive) dining nearby. This is hard on students! And postdocs! And anyone without a lot of extra cash!
Consider, for example, booking two smaller hotels together next time (maybe even with some cheaper hotels available nearby – the Raleigh meeting last year had lots of nearby, inexpensive choices). This would let you put it in a friendlier place, with affordable options for everyone. You can still have all the sessions in one hotel; it’s not like walking across the street is that much different than trying to navigate the Halo-level-like maze of the Westin Bonaventure in LA.
On the expensive note: you know you’ll make more money at the bar in poster sessions and whatnot if we don’t have to pay an arm and a leg for the alcohol, right? We don’t know if the pricing was SVP or the hotel, but man, it was bad enough we didn’t even want to bully our coauthors into buying us a drink.
Criticisms aside (which we hope are constructive – and yes, we’ll be sending an email to relevant committees, as soon as we figure out who they are), this was a well-run conference that we enjoyed. As we said, SVP is an excellent time every year and it’s well worth going.
We really enjoyed live-tweeting some talks and posters this year, thanks to our phones. There weren’t many people doing so – again, see wifi situation – so we got to feel useful! Getting to experience little bites via tweet of talks we weren’t attending was really nice, so we hope we were able to provide a similar function to others for the sessions we attended. It’s a bit difficult sometimes because in the really interesting and complex ones, you want to take notes, but you can’t take notes if you’re tweeting. We tried to strike a balance. Meeting a bunch of people at the tweetup was great, too.
In all it was a most excellent conference (not least because the two halves of fossilosophy were reunited for five days!), and we are looking forward to the next one. We’ll both be at SICB in January, Kelsey will be at NAPC in Febuary, and we are definitely looking forward to SVP 2014 in Berlin, Germany!
Every scientist, writer, thinker, or student has a notebook. Usually it’s a specific brand, binding type, or color, and it’s accompanied by a just as carefully chosen writing utensil – a fountain pen or industrial-strength fine-tipped Sharpie, perhaps. In many science disciplines this notebook is used to record everything from bits of conversations to datasets; lab sciences, especially, may demand high record-keeping standards. When it is full the notebook is dutifully labeled and placed next to its brethren, safe on a shelf for reference and nostalgia.
In this post we argue that the above procedure is the absolute minimum a scientist should be interacting with his or her notebook. In this age of constant communication, recording devices surround us. Indeed, depending on data type and the degree to which you wish to integrate a piece of data with your own intranet (as well as the internet), certain devices are more or less appropriate for any given situation. Through a carefully considered balance, a scientist can begin to record the highest-quality data with the least amount of stress…or at least notebook-specific stress.
There are many different recording devices available. Here are our favorites:
1) The Notebook
This traditional medium has many advantages; in paleontology, it’s often a hybrid lab notebook/research journal. It’s portable, forgiving, appropriate for talks, you can mix pictures and words or paste in bits of paper, and even tear pages out for notes or labels! The main drawback of a notebook is its preservability. (Not a word? We just made it one.) Many people write in pen, which can easily run with the addition of a little water or ethanol. Even a pencil can be erased. If the notebook gets dropped in a puddle or the ocean, the ink will run and pages will get soggy or disintegrate, and all those amazing ideas and data will be lost.
There are a couple ways to ameliorate this problem. The first is to Captain America-ize your notebook: get one with archival and/or waterproof paper like Rite in the Rain, a favored fieldwork notebook in paleontology. Always write in pencil – which can’t run or be removed by solvents, but can be erased – or awesome ink, though indelible pencil may be an interesting option (see here for a fascinating discussion of copying/indelible pencils and here for the quick definition). Pencil is often a good choice in the field, where many a good Micron has died a gritty ink-choked death thanks to dust and sand on the pages.
For a more thorough treatment of pen and pencil performance under various tests, including erasing, boiling water, and acetone, take a look at this excellent treatise (which also has more great advice on the reasons and finer details of keeping a lab notebook). Spoiler: Sakura Gelly Rolls, Sakura Pigma Microns, Sanford Uni-Balls, and the Zebra Sarasa pens performed well under all conditions. Sharpies are great for normal conditions but methanol, acetone, and ethanol prove fatal.
You should regularly scan, photograph, and/or photocopy your pages to provide a backup should your notebook be lost/stolen/eaten by your advisor’s dog. For bonus points, keep the backup somewhere separate from the original! Write your contact information inside the cover of your notebook with a cash reward for its safe return.
Date, location, and what you’re working on always go at the top. Number the pages if they’re not already numbered, and keep a few pages free at the front for a table of contents.
One major downside: only searchable by a written table of contents, your memory, or manually flipping through. One last advantage: you get to buy new notebooks and enjoy that delicious, productive scrape of pencil or pen across good-quality paper. Mmmm.
2) The Digital Camera
Pictures are essential in paleontology, not only for all the beautiful fossils you will study in a museum collection but also to record the way you conduct your research. Paleontologists are a very visual bunch and it’s surprising how quickly you forget how you set up an experiment or what a locality looked like. Take pictures of EVERYTHING. Every side of the fossil, the surrounding stratigraphy, the little tree by the side of the path that signals where you should go off-trail to find your locality, the drawer you found another fossil in, the way a dissection looked halfway through, the café that was still open at midnight in the middle of nowhere…
The advantages of the tourist mindset are twofold. Not only do you have pictures that may prove useful to your research in the future, you are also recording your activities for some lucky space-age historian. History loves paleontology, and we want our discipline to be represented as completely as possible to future generations.
Make sure you have plenty of memory cards and you upload those images as soon as possible, with backups (notes Brianna, who spent a few hours photographing little teeth for her advisor and was later unable to locate said photographs).
3) The Video Camera
Video-recording is, in some ways, an underused tool. What else gives you the ability to record 3D structures in real time? Complicated lab set-ups, dissections, and field sites can be completely recorded and commentary can be added as the camera is rolling. This can be helpful if a fossil, animal, or muscle identification or function is under debate. The ability to record the debate or quickly summarize actions will save you time, especially if your time visiting an institution is limited.
Bonus: also a great way to practice for better talks! Have a helpful friend record you running through the presentation. Much like reading your own writing aloud rather than in your head, watching yourself can make your presentation weaknesses (painfully?) clearer.
Again, upload, back up, and make sure it’s kept in a secure yet readily accessible format.
4) The Smartphone
A useful back-up tool, in addition to perennial source of distraction. Most smartphones have the ability to take notes, pictures, and video. Pictures and video are not going to be the same quality on each individual device, though, so don’t necessarily expect to have publication-quality photographs from your phone. Taking notes is perhaps one of the most useful functions.
Importantly, make sure things going into your phone don’t disappear into the abyss – find some way of centralizing your information so notes on your phone wind up accessible and linked to notes you take elsewhere (see number 6 on this list).
Many scientific apps can be found in any given app store, and they have the potential to be helpful or distracting depending on how you use them. Some basics you might want to consider are: a scientific calculator, digital level, stopwatch, flashlight, seismometer, and perhaps even a Brunton compass.
5) Word Document
The easiest way to take notes on a computer is by opening a Word (or Notepad, etc) document and typing. This is a fast way to take notes and the documents can be uploaded to the internet, shared with collaborators, and moved around quite simply.
Beware: without a clear filing system, you can easily accumulate hundreds of general little notes with cryptic names like “researchnotes camels.” Brianna recently spent a few hours of a work day untangling old, disorganized file structure from a more foolish point in her research career – splintered research meeting notes and brainstorm sessions everywhere, data in Excel spreadsheets whose purposes were lost to time, instructions buried in email archives, plans in the Google Notebook graveyard. It’s fixed now, but the potential for confusion and lost data was high.
Date your files, label your files, figure out some sort of organizational system. If you really want to get clever, keep file names and descriptions in your notes somewhere.
A caveat: the privacy policies of cloud storage sites in general have come under fire. Do some reading on the security and privacy of the service you choose, and put some thought into where you keep data that may be particularly sensitive. Here’s one place to start, from the writerly perspective.
For file structure, think wide rather than deep: many subfolders per folder. For the moment, underneath the main “Science!” folder, Brianna has one folder for each major ongoing project with its nickname: Thesis, Camel Feet, Cave Ponies, etc. One esteemed scientist we know puts “Damn” at the beginning of every active project’s folder name so that all the active ones are in the same place.
7) Random Scraps of Paper
NOT RECOMMENDED! Whatever paper is lying around should only be used in an emergency, as these are easily lost or destroyed. In fact, it’s advisable to take a picture of your “napkin note” as soon as you can, before your best friend decides it’s a good time to blow their nose.
8) Your Mind
NOT RECOMMENDED! You may think you’ll remember that critical specimen number, or how many sesamoids a camel has, but then twenty other important events will happen in the next hour and important facts will start spilling out your ears. No matter what external memory device is in your vicinity, use it! You won’t regret it.
Our personal systems:
Brianna uses a waterproof thesis-notebook (turns out to be helpful when painting dots on muddy horses in the rain) that really ought to get scanned, a regular all-the-other-paleo-research notebook that gets scanned semi-regularly, and text/Microsoft Word files in project folders in Dropbox. Next addition will be an external hard drive.
She’s been considering dipping a toe in the Evernote waters, just to have a gloriously centralized place for all project ideas/notes/things, but is still kind of grumpy that sharing notes between collaborators would be much more difficult than just sharing a Dropbox folder. Alas, the perfect solution remains out there.
Kelsey uses a similar system, with Dropbox files for digital documents, three-ring binders for projects, and notes in a single spiral-bound lab notebook. She would like to transition to a Better Notebook in the future.
A Last Thought on Redundancy
In general, your data should be safely stored in multiple, redundant ways. If any one (or, worst case, two) of those backups fail, you should be able to quickly and efficiently access all your important stuff. So, some combination of and multiples of:
Physical copies of notebook
Local storage on device(s)
External storage on hard drive/DVD/whatever
Of course, the challenge is to keep all these locations up to date, safe, and separate. But if someone runs off with your precious laptop, you drop your external hard drive, Time Machine decides to stop working without telling you, or you drop your notebook in a river (we told you to get waterproof!), you will be glad you put in the effort.
Extra Credit Reading
Field Notes on Science and Nature, a beautifully written and illustrated collections of essays on, well, field notes. Contributions from scientists of many types. Highly recommended reading.