Commodifying nature

Here's a picture of a beautiful place in Thailand (thanks, Google image search). Nice, right? What if I asked you to tell me how nice you think this vista is, in dollars? Is it a hundred-dollar-vista? a five-dollar-vista? How much would you think it would be worth to not have it contaminated by a small quantity of animal waste from a nearby farm? What about a large quantity? What if I had to cut all the trees down to build farm to feed hungry people? Would it be worth it?

This is the major problem that environmental economics has to deal with. The price of some ecosystem services (things that ecosystems do for free just by existing) can be pretty easily quantified. For example, a forested watershed will naturally filter out pollutants and prevent a water supply from being contaminated. We could calculate the value of this ecosystem service by finding out how much it would cost to put in a water treatment plant to eliminate pollutants in the place of the forest. You can know the price of things that are bought and sold on the market, like water treatment equipment, but the price for a nice view - that is more difficult. But we all agree that it has value to individuals and to society as a whole. Most people would be "willing to pay" something for that nice view. There are a couple of ways that economists use to try to quantify this "willingness to pay." They all have their flaws. Let's highlight a couple.

Travel Cost Method
This is a way of getting at the "use value"of something like a natural area that people like to visit. Basically you get an economics grad student to hang out at the site and pull people aside to take a survey about how much it cost them to get to the site. The survey might ask questions about how far they traveled, if they took a plane or drove, how much money they make, how much time they had to take off work, and how much they saved up to make this trip. This is a pretty direct way to get at how much someone would be willing to pay to be able to use the site, visit the site, see the site. Problem is, not every site or environmental resource is something that someone might visit. For example, the site could be hella remote, only enjoyed by penguins and polar bears. Or the site could be nothing particular to look at, just the home of some key endangered species.

Hedonic Pricing Method
This method compares prices of similar items with or without some environmental benefit attached to see how much extra people are willing to pay for the environmental benefit. For example, to figure out the value of a park you might see how much a three-bedroom house goes for next to the park compared to one that's a few blocks away from the park or in another neighborhood. This is problematic because no three-bedroom houses are exactly alike except for the neighborhood so there are a lot of statistics needed to try to isolate the variable you're interested in. Also, it has the same problems as the travel cost method as it is most easily used to define the value of a site that is close to human habitation and used for recreation purposes.

Contingent Value Method
This method is the simplest in theory. It consists of basically asking people - how much are you willing to pay for this environmental thing? Typically you ask them about how much they would be willing to pay to enter an area, or how much extra taxes they'd be willing to pay to see that area protected. You can frame the questions a million different ways, which could introduce some bias into the valuation. Also, there's a strategic bias in this method because the money that people would be willing to pay is hypothetical money. So if, for example, you were really poor but also a real tree-hugger (hey, maybe you live in a tree!) and someone asked you how much you hypothetically would be willing to pay to see a forested area protected, you'd say "All the money I have" or "a million-gillion!" Even though the reality is, you wouldn't ever be able to pay that much. Despite this bias, the contingent value method is kind of the only way to get a sense of the "non-use" value of an environmental resource. A "non-use" value is one that you give something just for existing, even if you never use it or visit it. For example, let's say that the sonar equipment from ships is making it too noisy for orcas to hear each other singing. This is making it difficult for orcas to navigate and to reproduce, decreasing their numbers. No-one really hunts orcas for meat anymore and very few people have the opportunity to see orcas, especially if you live in a land-locked state like Missouri. But, how much extra would you be willing to pay for your "chicken of the sea" to make commercial vessels reduce their use of sonar so that orcas could thrive? How much is it worth just to know that orcas will continue to exist?

All of these methods have a little bit of a flaw in that they are all based on either the public's behavior or the public's stated preferences. There are some unpopular environmental resources out there that have a really important role in balancing ecosystems. Wolves are a good example. Without these predators, deer and other herbivores's populations increase, causing overgrazing and biodiversity loss. This has multiple effects, some of which could directly impact humans, like increased tick-borne disease. But if you asked the average person how much they'd pay to have wolves roaming their woods, they would probably tell you how much they'd pay to have the wolves removed from their land.

Environmental economics

"It is one thing to advocate doing the 'right' thing; it is another thing to advocate doing the 'right' thing regardless of the cost of doing so." 

Michael Harris of University of Melbourne in 

"Environmental Economics"(1996) The Australian Economic Review. 29 (4): 449- 465. 

The quote above helped frame the discussion of environmental economics for me. Most people want to do the right thing by the earth. In fact, here's some statistics to back that up. (Thanks Statista!)

Over half of the people surveyed in every age group said they agreed that yes, they felt a little guilty when they did something unfriendly to the environment. When you look at how that translates into consumer preferences, it appears that globally, the percent of consumers who are willing to pay extra for environmentally friendly products has increased and is now over 60%.

But not everyone can do the right thing at all costs.

Example: I'd love to be able to purchase meat and eggs from a farm that practices sustainable, humane animal husbandry. But alas, I must go to Aldi (if I link to you from my blog and talk about how much I like you, will you give me free food, Aldi?) and buy what I can afford.

And a lot of people might say, well, that's all good, since that's free market economics for you! Producers who can maximize their output and minimize their costs (by raising animals CAFO-style) capture more of the market share because they can price their goods lower, and more consumers can afford those products and more people can have food to put on the table. A chicken in every pot! Benefits all around! If we were to require CAFOs to do more to minimize their water pollution, their costs would increase and their supply would necessarily decrease, causing the price of meat products to rise. People wouldn't buy meat as often, shifting demand from meat to other protein sources like beans. The meat producers would suffer, people in vulnerable rural communities would lose jobs, and the economy would suffer! All of these are definitely costs of requiring more pollution control on CAFOs. Which brings me to my final graph of the results of a survey of "affluent" Americans (read- filthy rich by teacher and librarian standards).

When these folks were asked if economy was more important than the environment, they were more or less evenly split. What this says to me is that a lot of respondents in this survey feel that both the economy and the environment have some importance. Of course, they're right! Is a business subjected to new environmental regulation-related costs going to increase their revenues, profits, dividends, salaries, hiring rates? Probably not. The economy will suffer and people will suffer as a result. That's a big deal. Those with a perspective favoring the environment, however, will counter that the human costs of pollution are at least as worrying as the economic costs of controlling that pollution - contamination of water supply, insect and disease outbreaks, collapse of fisheries, loss of recreation opportunities near polluted streams, soil erosion.

So what environmental economics tries to do is to quantify costs and benefits - both economic and environmental, in order to better inform our decision-making process. Is controlling pollution worth the cost?

Problem is, while something like a manure lagoon to control animal waste release has a price and therefore its costs can easily be quantified, the cost to the environment is not easily priced. This means to get an accurate picture of the environmental costs, the value of a clean stream or of a unmarred vista must somehow be quantified, "commodified" as it were. Some people aren't all that comfortable with this approach, because some natural things seem as if they should be "beyond price." Think about the majesty of the synchronous fireflies sparkling through the night in the Great Smoky Mountains. No price gun could ever touch it, so what's the point?

But, here Harris helps me to understand again: "...if we treat any part of nature as being 'beyond price', then we have implicitly assigned an infinite value to it. If infinite values are assigned to all of nature, none of it could ever be changed in any way."

So, we have to give that natural bounty some kind of value, somehow, if we are ever to accurately weigh the balance of costs and benefits of any proposed change. How do environmental economists do this difficult task? How about another post on that?

Back to the blog

"To every thing there is a season, and a time to every purpose under the heaven" Ecclesiastes 3:1

I've been preparing all sorts of changes to my AP Environmental Science (APES) class for next year. The subject matter makes it probably my favorite class to teach, but unfortunately, circumstances have not allowed me much time to make the class my own.

Allow me to explain. First, I met a guy. A really great guy - a cute librarian and word nerd! Then, I went on the job market and scored a great job in St. Louis at a great private school. As a result, I moved away from great guy to a new town and started a new teaching job with new preps, new coworkers, a new work culture, new everything. The amount of time I spent talking to him on the phone every night was easily enough time to revise an APES course, but alas, priorities! The great guy and I decided we ought to just go ahead and get married- in August, for a December wedding. Yes, December the same year! Wedding planning took over my life then, and then getting to the wedding date without imploding, then getting married, going on a honeymoon, moving my new hubby and our four cats, and then it was back to school for second semester. There was barely time to exhale, let alone make changes to my curriculum. We adjusted to married life just fine, squeezed into a tiny apartment in the city. Hubby got a job. Then we moved again. And again. During the second move my new science department was also moving into temporary spaces as we prepared for the construction of our resplendent new building opening this fall. Hubby got a new job. We bought a house. I worked for a year in a big-ass trailer temporary structure. We planned a vacation to Europe. We lost a cat and gained a new kitten. The active volcano of change in my life returned to spewing out a more manageable slow bubble of hot molten newness.

I ended the school year this June as exhausted as ever, and I immediately traveled to Cincinnati to attend the APES reading, a week-long festival of grading funded by the College Board®. There I read/graded 1504 responses to an essay question about indoor air pollution and talked to numerous other APES teachers. I joined the APES teachers Facebook group. My eyes were opened. My class was a St. Louis dumpster fire. Three years of just slightly tweaking what my predecessors had done was just not cutting it. To be clear, this has had nothing to do with my students' AP scores. They're very well-trained monkeys when it comes to standardized tests. They always score above average. Their scores are not the problem, it's how miserable my students and I feel throughout the year-long slog.

So I started over. I vacuumed out all the corners of my syllabus, leaving just a few select labs and the test dates arranged for the new school year. I've been refilling it slowly, this time with stuff that I really like, that I find valuable, that I know my students will enjoy more. One thing that really put a speed bump in my path was trying to "get" environmental economics. Every year I try to lead my students out onto a skinny diving board above an Olympic-sized swimming pool of information about economics and try to point out a few key things that they should know about. Inevitably, I get it wrong, slip off the grip tape, and end up drowning in a sea of questions that I can't answer about a subject that I hated in college. More on that in my next post!

Synchronicity

This June I went to see the only species of synchronous fireflies in North America. Every year, for only two weeks in June, these tiny nocturnal beetles emerge as adults to find a mate, lay their eggs, and die. During this cyclical eruption of fireflies, the adult males do as most males of the beetle family Lampyridae do. They try to find a mate by flashing their light organs until a female flashes back. Some species have kind of primitive light displays, the males zipping around, hovering low over the dark vegetation with their light organ glowing like running lights. When a female responds with her own flash, he puts on the brakes and flies down to her for a little coffee and conversation and if he is lucky, the chance to make baby fireflies. Other species have complex flash patterns, the males executing a precise "flash dance" to identify their species to their female audience. Then there are the synchronous fireflies. These are truly special, because instead of each male flying and displaying individually, lone wolves at the singles bar that is the forest undergrowth, the males of synchronous species display all together, an army of synchronized dancing flashes of light across the hillside. Some species of synchronous fireflies, like those that light up in mangrove trees along the rivers of Thailand, flash on and off together seemingly instantly. The ones that I went to see in the Great Smoky Mountains this June seemed to have a more loosely organized display. A region of the hillside would begin to twinkle, each male flashing 6 to 8 short bursts, then the wave would travel across the forest floor, the twinkling spreading until the whole hillside was flashing. Just as soon as that happened, the whole hillside would be dark, except for a few other species of fireflies, their running lights engaged, meandering between the weeds. Wave after flashing wave would travel through the forest like a silent beetle disco late into the night. Few people get the chance to see this phenomenon once in their life. I have now seen it twice. I am so charmed by this light dance- both its visual effect, and the joy of visiting Elkmont just to see them, like a pilgrim entomologist coming to pay homage. For me, this event is a time of renewal, like New Years' Day. It comes at the beginning of summer, when I have just slogged through another year of teaching. It is a time for me to reflect on how the year went and to start forming goals for next year. One of my goals for this year was to write more. So here I am, resuscitating this blog as a little creative outlet. If anyone is reading this, I hope you have a renewal time like this every year- some event that reminds you to light up and fly while you still can.

Firefly image by Flickr user scyllarides. Used under Creative Commons license Attribution-NoDerivs 2.0 Generic.

Laboulbeniales

I've been writing a lit review about insect-fungal interactions. This is probably the coolest thing I have re-discovered in my reading. Laboulbeniales is a group of fungi that live on insects. Unlike other fungi that like to snack on insects, though, the Laboulbeniales like to hang out on the outside of the insect. Here you can see them attached to a ladybird beetle, sticking out like tiny yellow spikes. The fungus is anchored to the insect's cuticle, with roots extending down into the insect's hemocoel, drinking their juices. This way, the fungus can live and let live, feeding but not killing its host. More information here:
Laboulbeniales
Laboulbeniomycetes
Harmonia beetles with Laboulbeniales

Photo from Wikipedia, used under creative commons license.

Luciferase - Enzyme of wonder

Firefly light production itself is kind of a little miracle. In their light organs, the enzyme luciferase oxidizes luciferin in a reaction that converts almost all the energy of the reaction into light without producing excess heat. The light can be turned on and off by the coordination of nitrous oxide production to liberate oxygen to participate in the reaction.

Things that make you want to become an oceanographer

Yeah, it's a jellyfish. A really huge blanket-like jellyfish called Deepstaria enigmatica. I love it!

Dissertation

So, I'm writing a dissertation. Supposedly. Supposedly it needs to be finished in less than two months. Supposedly I am the person who will accomplish this feat. While teaching 5th-grade science. Here's what's killing me: I'm not working on it. I'm freaking out instead.

In undergraduate, back when I was an English major, I would read something the week before the big paper was due. Then I'd spend an afternoon in the library reading a few sources about things I didn't understand in the thing I read. Then I'd sit down and write a paper from start to end. I'd lay that paper like a golden egg, the product of a week's worth of reading and thinking and composing in my head magically squirt out of my brain's cloaca all at once. I'd put myself to bed and in a week or so get back a paper full of glowing praise. It made me feel very clever.

The dissertation is nothing like those old English papers. The dissertation is built word-by-word, a stone castle perched on a 6-year-old garbage heap of data. Every step makes me feel stupid. Every word is scrutinized by the perfect scientist who lives in my brain and judged. Rarely does a single sentence escape the retreating cursor.

I called Kelly about my sudden and acute dissertatiophobia. She commanded me to stick butt to chair and do something. So I tried it. I did one little task. Then I did another. Doing something made me feel loads better, and I worked the rest of the day, taking a break for a late lunch and a late dinner before talking to Kelly again.

She reminded me that I'd need to finish one chapter per week if I want to have a full draft by May for Jim. I have enough of a start on two of them that finishing the two chapters won't be too bad. It's the unknown chapters that scare me still. Is that part of the garbage-pile firm enough? Or will the west wing collapse under its own weight. Only time will tell! Short, brief, momentary time. Finish this first part by Wednesday? Yikes! But it can be done.

Giant stick insect rediscovered, fails to win beauty contest

Photo by Patrick Honan/Nick Carlile.

You might have seen this Giant Stick Insect Article from NPR recently. It tells the story of a crazy large stick insect from Australia that disappeared in 1920 and was thought to be extinct, only to be re-discovered clinging to life on a tiny rocky island in 2001. Scientists brought a few of them back home and managed to breed them in a zoo.

Great news, right?! Totally sweet insect saved from extinction! Now we just have to get rid of the rats that ate all the original population and we can once again have these massive tree-lobsters roaming all over the place!

Except...
"Will ordinary Janes and Joes, going about their days, agree to spend a little extra effort and money to preserve an animal that isn't what most of us would call beautiful?" (says Robert Krulwich in the NPR article)

Should survival be a beauty contest?

Wondermark comic about animal language

Here is a link to the comic


I love Wondermark. There are a number of highly amusing science comics by Malki that rank among the best comics I've ever LOL'ed at. This is no exception. Here, encapsulated in a simple webcomic, is all that I have wondered about human and animal 'language.' We consider ourselves sophisticated users of language because we have things like arbitrary signs (like beeping for instance), ability to talk about displaced or non-existent objects, and infinite flexibility of expression. However, these very things that we consider to make our communication of a higher order than the rest of the world, also makes our communication more obfuscated. A wolf's growl communicates in perfect clarity and simplicity across multiple species. No one needs to learn what it means, and no one needs any more information than it provides.

Wetas

Above and Beyond in the Down Under: Cool Creepy Crawlies.
The snow today reminds me of the alpine weta, a creature that can survive being frozen solid. May we all weather our trials with the same cool-headed-ness.

Plants (who knew?)

You may be surprised to find that now we're going to talk about the communication systems of plants. Turns out plants can be pretty smart for creatures without brains, nerves, muscles, or specialized sensory organs. When evil herbivores like caterpillars start to munch on plants, plants do not have the option of running away. Instead plants stand their ground with a full arsenal of defenses. Many of these defenses have a direct affect on the herbivore. Direct defenses are things like antifeedants which deter caterpillar feeding, toughening agents that make the plant tissue hard to digest, hairs called trichomes that make the plant tissue spikey and can secrete noxious chemicals, proteinase inhibitors which stymie digestive enzymes in the insect gut, and caterpillar poisons which can kill 'em dead. Direct defenses are the bread-and-butter of plants under herbivore attack. There is another kind of defense, however, called indirect defenses - a way to "call in the cavalry" so to speak.

Most every insect has an arch-enemy - a parasitoid. Caterpillar parasitoids are usually tiny wasps. When a parasitoid wasp finds its host caterpillar, it will lay its egg(s) in the caterpillar. The parasitoid wasp's eggs develop inside the caterpillar and will eventually, Alien-like, pop out of the caterpillar to pupate and complete their development into adult wasps. This is a pretty painful process for the caterpillar, which is essentially converted into a wasp-incubator and then dies. You may be wondering how a little wasp finds the right caterpillar. It's a bit like looking for a needle in a haystack, right? If only the haystack would tell you where the needle is hidden! Well, that's essentially what plants do when they activate their indirect defenses. In response to specific compounds called elicitors in the caterpillar's spit, the plant will launch a beacon consisting of a unique blend of odors (usually a blend of terpenes). Parasitoid wasps are attracted to these odors, and come flying to aid the plant by parasitizing the caterpillars trying to catch a meal off the plant. The smell of the beacon is only activated by the caterpillar's spit, and is unique for each species of caterpillar, providing a reliable signal for the parasitoid wasps to find their specific host. The plant-insect communication system really works because the parasitoid wasps are very sensitive to odors and very good at associative learning. They can associate just about any odor or complex odor blend with the stimulus of laying an egg in a caterpillar. Once they've had the experience of finding caterpillar hosts on a plant that smells just so, they will continue to seek out that smell to find more caterpillars. It's a win-win - well, at least for the plant and the wasp.

So we have a great example of cross-kingdom communication. Why don't plants talk to each other? If you were a tomato plant like one in my garden, crowded up against your neighbors, you couldn't help but 'overhear' when one of your neighbors gets attacked by an herbivore by sensing the parasitoid-calling odor beacon and other compounds that are released when a leaf is damaged. And if your neighbor is being munched, odds are good that you might get munched soon too. Probably should go ahead and load your guns. This is the theory behind priming - that the perception of herbivores feeding on neighboring plants allows undamaged plants to be primed to mount a faster, stronger defense response when the herbivores eventually come for them too. Interestingly, the existence and importance of priming in various plant systems is still in question. For one, plants aren't real cooperative or social creatures, so we don't really expect them to be selected to lend a hand to their neighbors. Also, it is not necessary to assume that just because you can smell the smell of a damaged plant you will certainly be next on the herbivore hit-list. In addition, some have scoffed at the idea of priming just because plants don't typically come equipped with noses with which to sense odors from neighboring plants. Though, is communication dependent on having a mouth and tongue to make words or ears to hear them?

Ichneumonid parasitoid wasp image by Tony Wills [http://www.gnu.org/copyleft/fdl.html], CC-BY-2.5

Lighting Bugs: The Flash and the Furious

Photo "Star Trails and Fireflies, June 22, 2009" by Steve Irving, used with permission

Nothing quite expresses the sublime joy of watching fireflies paint the night sky with their glowing tails. Few realize, however, that their beautiful language is for the purpose of mating. Male fireflies take off just after dark, emitting a telegraphic pattern of flashes that can vary in intensity, shape, length, and periodicity. Each species has a unique flash pattern which the female recognizes among all the other flashes as the one belonging to her species. In between pattern repeats, the male waits for the female to respond with her own characteristic flash from her hiding spot in the vegetation. When he catches sight of her come-hither flash, the male circles back, repeating his flash pattern and waiting for her to repeat her response. This way the male and the female firefly call to each other in the dark until they locate each other and consummate their romantic conversation.

Fireflies are beetles belonging to the family Lampyridae. They spend most of their lives as larvae (glow-worms), living in dark and muddy places and preying on snails. Like moths, their adult lives are short. Like moths, many beetles related to fireflies will use sex pheromones rather than light to attract their mates. The unique bioluminescence of fireflies, however, allows them to wait until dark (when birds and other predators are asleep) to come out to mate. Specific flash patterns make the species immediately identifiable from a long distance at night. The frequency and intensity of light flashes can also communicate information about the male's quality as a mate. These advantageous aspects to light communication has led to the evolution of light-based sexual signals four times in the firefly lineage.

The flash dance of fireflies can be exploited, however. If you're skilled with a small pen-light you can trick male fireflies to land on your hand by flashing back at them as a female firefly would. Females of the genus Photuris have also learned to pull this prank on male fireflies. Photuris females will call to males of other firefly species, but not for mating. These femmes fatales are looking for a snack. The male, oblivious to the fact that the female below is not of his own species, flies straight into her welcoming jaws.

Figure of firefly flash patterns by J. E. Lloyd, University of Florida from Fireflier Companion (1998) 1(4): 56.
Image of Photuris female munching on male also by J. E. Lloyd.

Moth Madness

Adult moths live much like many college students in that their lives revolve around sex. During their very short existence, their only imperative is to reproduce. To this end, they have a streamlined chemical communication system. The female moth produces a unique chemical compound which is known as the sex pheromone. This arousing perfume is produced in glands in her rear end in extremely minute quantities (picograms (10^-12 grams) per hour). The male's antennae are attuned to this odor and can sense her pheromone from afar. Like a bloodhound, he homes in on the female. Actually, the male locates the female by following her scent upwind. No need to even be able to follow a concentration gradient or make interesting small-talk. It's dead simple.

Once male finds female, close-range signals such as compounds present on their cuticles can tell the moths something about each other and their qualities as a mate. When you don't live long, though, it doesn't pay to be picky. The response of male moths to sex pheromones is so predictable, sex pheromones are a great way to control pest moth species without pesticides. A trap like the one in this picture uses an artificial lure imbued with sex pheromone. Males are attracted to the trap, but instead of finding a lovely lady, they find a surface covered in killer sticky slime.

Another way of controlling moths with sex pheromones is a method known as mating disruption. The sex pheromone is often loaded into little plastic tubes like this one that can be hung from trees. Sex pheromone produced by the real moths will be mixed with synthetic pheromone being produced by scads of tiny plastic tubes. Flooding the whole area with sex pheromone makes it very hard for males to locate females. Even when they do manage to find the odor source, a bit of plastic is a poor reward for following a odor plume.

The simple sex pheromone communication system of moths does not constitute a language. But while simple, it is extremely effective, providing a reliable, low concentration, long-range signal requiring minimal energy investment for either the sender to produce or for the receiver to interpret. Moths need no online dating service with its 29 dimensions of compatibility. They already have a language tailor-made for fast and easy hookups.

Pheromone dispenser photo by Eugene E. Nelson, Bugwood.org, used under a Creative Commons License.

Honeybees - starting at the end

When starting a lecture on animal communication, most people would probably leave the honeybees for last. Only because their communication has some unique linguistic features most other animal communication lacks. Namely: symbols. Honeybees have an elaborate language for communicating the location of food and shelter through dance. We have decoded most of it due to the Nobel Prize-winning work of an Austrian named Karl von Frisch.
(Herr Dr. von Frisch looks great in lederhosen, don't you think?).
Karl von Frisch discovered that European honeybees (Apis mellifera) could communicate the precise location of a resource by dancing.
(Can you imagine anything more wonderful? What if we communicated through dance alone? Tell me that doesn't sound like fun.)
The dance has two components: an angle and a distance - all the bees need to find a location. The angle is communicated by the angle at which the bee takes a waggle run relative to straight up. Outside, this angle corresponds to the angle of the resource relative to the sun. The length of time the dancing bee spends waggling corresponds to the distance to the food resource. When a forager bee comes back from collecting food, she will dance, and in the dark hive, other bees will surround her and follow her dancing movements repeatedly, extracting the location information from her movements. Then the foragers will set out to the location she indicated. This is the basic formula for the dance language. Other aspects, such as sharing nectar samples, floral odors, and vibrational signals also play a role in telling the other bees the type and quality of the food resource.

The dance language is also used when a swarm (a newly budded bee community ready to start their own hive) needs to find a hollow cavity to nest in. Scouts that find a suitable cavity dance to communicate its location to the other workers. The better the cavity, the longer a bee will dance for it. This length of time spent dancing is key to the collective decision-making of the swarm, which must take off all at once and move together if they are to survive. The longer a bee dances for a location, the more recruits she will get to check out the possible new home, and the more bees will come back to dance for that location. Eventually, almost all the scouts will be dancing for the preferred location. Once they have reached a quorum, the bees take off to colonize the new home.

So that's the fantastic story of the honeybee dance language. My question is: why so sophisticated? Why do honeybees alone among invertebrates demonstrate use of symbols? Why are honeybees considered the pinnacle of insect communication? Honeybees themselves are not very remarkable insects. Physiologically, they are similar to their bumblebee and wasp brethren in brain capacity. One thing that they do have that many other bees and wasps lack, however, is eusociality.

Eusociality is the term we use to describe social animals where there is:

1. Reproductive division of labor - some individuals reproduce while others give up or delay their own reproduction
2. Overlapping generations - individuals from previous generations live together with individuals from the current generation
3. Cooperative care of young - non-reproductive individuals rear other individuals' offspring

Only a handful of animal species fit this definition. In many ways, honeybees wrote this definition. A single queen bee lays all the eggs in the hive, while the workers (sisters and offspring of the same queen) do all the work of gathering food, feeding the young, constructing, maintaining, and guarding the nest. The honeybee hive functions as a super-organism, with each individual doing its part to serve the hive. The critical phase in the reproduction of this super-organism is the swarming stage, when the hive buds, and a group of bees and a queen must choose a new nest. For the European honeybee, which requires a suitable cavity, this selection process is very important to deciding the future fate of the swarm. You could imagine that the selective pressure would be extremely high for an efficient way of communicating the location of a possible new nest site.

This is only one theory that might explain the evolution of such complex behavior in honeybees rather than other species which do not exhibit swarm-founding. Indeed, the selective pressure for more advanced communication must increase with increasing levels of cooperative behavior. Is this true? Do we find other examples in the animal kingdom of advanced communication in conjunction with cooperative behavior?

Animal Linguistics Series

My linguist friend has invited me (ok maybe I volunteered) to give a guest lecture to her class. In this lecture, I will cover a number of examples of animal communication and compare and contrast these communication systems with those of humans.

Linguistics has always seemed very interesting to me. I might even classify myself as a word geek. I collect new words like shiny insects, pinning them down by using them often. I am very good at crosswords.

Communication in the animal and particular the insect world, however, is rarely possessed of such nuance as actual words. Nevertheless, animals say a whole lot with chemical, sound, and visual signals. Some animal communication systems are surprisingly complex.

To prepare for this lecture, I'm going to go through a few outstanding examples of animal communication over the next several days. Enjoy!

What is a cockroach?

Green cockroach (Panchlora sp.?), originally uploaded by pbertner.

This is a cockroach, order Blattodea. Insects in the order Blattodea (or Blattaria if you're old-school - either way it's a roach) are characterized by long, slender cursorial (running) legs with which they achieve impressive speeds. The top of their first thoracic segment (aka the pronotum) extends up to cover their heads as a shield-shaped hat. Their mouths contain a pair of plain, sensible mandibles for chewing, their 30+ segmented antennae are thin and sensitive, ranging far ahead of their body to warn of impending danger as they run. In those cockroaches that have wings, the first pair is thickened, leathery (they're called tegmina), protecting the hind pair that is thin and membranous.

Many cockroaches are earth-toned: dull brown, tan, red, and black. A few, like the beautiful cuban cockroach (Panchlora nivea) pictured above, have striking coloration.

One thing a cockroach is not, however, is fancy. You will never find them trying to stand out with flashy patterns. They are meant to blend in with the background. Flat bodies, shielded heads, leathery forewings, the body of a cockroach is made for sneaking into small hiding places and for furtive avoidance of malicious predators. Their beauty is a functional one.

Confessions of a Cockroach lover

MMMHHhh tasty water!

I have a confession to make. I am not afraid of cockroaches. I know, I should be. They carry diseases, they cause allergies, they're icky and run too fast. All of which, in any normal human being, should be cause for alarm.

But I just can't do it.

Why? Because they're just doing their jobs - fulfilling their cockroachy calling. Allow me to explain.

Living things are messy. It's true. We secrete and excrete and shed everywhere. When we eat, we always leave crumbs and sticky smears behind. Then we go and die and leave our messy bodies behind. Someone has to pick up the trash. A lot of times, that someone is an insect. Dung beetles specialize on picking up our crap. Ants will happily take our crumbs and lick up our sticky residues. Flies specialize on cleaning up our dead flesh after we've left this world. Cockroaches aren't really specialists. They are the garbage-men. You put it out, they pick it up.

We humans have taken messy up to a whole another level. We have made certain choices to live certain ways that create a lot of garbage. This garbage is typically a mixture of components, bits of organic matter hidden in pockets of inorganic containers and structures. The inorganic stuff is pretty useless to the rest of the living world (not entirely useless, but requiring a great deal of time and energy to return to a useful state) but the organic stuff someone can always use for food. But then who's going to go and extract it? What garbage-man would come into your house and take away all your crumbs from under the fridge? Lick our your yogurt containers, scarf up the stale cookies in your pantry, and clean the slime that clings to the inside of the drainplug in your tub? Cockroaches, that's who. They're the most effective garbage-men ever.

Their all-encompassing garbage-picking skills is what makes cockroaches susceptible to contamination by various nasty microbes. These valiant trash-men don't mind exploring your toilet brush and then your kitchen counters for delicious morsels. 'Clean dish' and 'dirty dish' is not a distinction that they know how to make. So the problem with cockroaches isn't so much the roaches themselves, but the microbes they accidentally pick up when they're on clean-up duty.

Funny thing about those microbes, though- they were already hanging around. In most cases, they were as close as your bathroom floor and your sink. The cockroaches just moved them around. Cross contamination: it's the worst kind of cooties.

So how do you keep the cockroach garbage-men on the curb? Keep your trash there too. Clean up after yourself, and the cockroaches won't have to come and do it for you.

Coco plums

Coco plums, originally uploaded by allspice1.

It's a hedge, it's a tree, it's a delicious edible fruit! It's a Coco Plum! Next to Palm and Pine it is also probably one of the most over-used obligatory plant-name/business-monikers in the tropics. Seriously, there's a resort in Belize, there's a Beach and Tennis Club in Key West, and an appliance store in Vermont (?) that all get higher google ranking than the wikipedia article about the plant.

But it shouldn't be so. It's a very nice plant, Chrysoblanus icaco. All over south Florida, every well-groomed native planting and every scrubby wetland ecosystem is bursting with this attractive, round-leaved native plant.

It has two varieties- an upland and a coastal type. In the picture above you can see the fruit of the upland type. This coco plum can become a bushy tree up to 10 feet tall, bearing dusky purple fruits and dark red growth tips. The coastal type, on the other hand, grows shorter, maybe three feet tall, its new growth blushing only slightly, and its fruits a soft white to pinkish-purple as below.



As my parents and I strolled through a coco plum corridor in Apoxee Park, I squeezed the soft white and pink fruits, wondering how they would taste, but uncertain if their attractive, smooth skin hid poison beneath. My grandmother came to visit us for Thanksgiving and encouraged me to taste the upland variety on another hike. The dark purple fruits turned out to be mostly seed, with a thin layer of white bread-like pulp, dry but sweet. It retreated from my bite, mashed into a shiny white mold of my front teeth. The dark eggplant skin was thick and a little rubbery. I found myself disappointed that I couldn't find more juice in them.

Powering the Cell: Mitochondria

Yay cell biology!