Behavior

Look at me! I'm a highly advanced vertebrate and I'm using a machine built by other members of my species to produce words on a screen. Those words are going to be sent to yet other members of my species and perhaps they will read. Perhaps they will learn.

It would appear that I am behaving. Because of a combination of internal and external stimuli I am engaging the world and acting on it.

Now what about a plant? A plant can turn to meet the sunlight. Some plants, like a Venus flytrap, can even catch animals and "digest" them. Does a plant behave? Most people would probably say no, that a plant "reacts" to its environment. But in a strictly Skinnerian way of looking at things I'm not so different from the plant. If you observe us we move. We attempt to get closer to food, water, etc., the things that make us survive.

I've been thinking about this stark comparison for two reasons: First, I've been talking about behavior a lot with school children around grade 4 or so and when you ask them what behavior is they usually tell you something like "well, it's when you've got good behavior or you've got bad behavior and that's when your mom and dad tell you to behave." From my conversations it seems like one of those words that children use but don't really understand.

But I'm not really sure us adults understand it any better. When I define the word for my students I usually say "it's what the animal does" (this is in the context of studying animal behavior). But if you tried to apply that definition to say, a car, you'd sound a little weird. "The car is behaving. It's behavior is...what the car does." Clearly cars do stuff but we know there's nothing internal that's directing their behavior. So is that internal response to external stimuli what makes the "does" behavior and not just "does?"

The other reason I've been thinking about behavior and what it means exactly is because I finally caught up with some research that came out a while back that led some to claim that cnidarian jellyfish (just jellyfish for those who don't care to think too hard about taxonomy today) have brains. Previous thinking was that all they had was a "neural net," too diffuse and sparse to control any kind of directed behavior. The difference between your brain and any old neuron is that your brain's neurons are all super close together and there's a lot of them so all the neurons can be assigned different jobs and they can all talk really quickly together. Unlike the neurons that detect pain or move my muscles, for example, they are the ones really producing the behaviors rather than just carrying them out. Most invertebrates have what we call "ganglia" which are kind of like proto-brains so to claim a jellyfish had a brain...seemed ridiculous.

And it was. You may remember this story if you follow The Science Journalism. It was covered in the New York times. Here's a link to the story. I think this is just horrible science journalism and here's why: I went to the abstract of the actual paper. It does no such thing as to claim jellyfish have brains. It claims they have some centralized "ganglia-like" (so think proto-ganglia or proto-proto-brain) nerve clusters. The author does not use the word "brain."

It's a second scientist quoted in the paper, one Doctor "David J. Albert, a jellyfish expert at the Roscoe Bay Marine Biological Laboratory in Vancouver, British Columbia" who makes the following claim: "That's what a brain does. It controls behavior." The journalist fills in the bit about if it behaves, which it turns out jellyfish do sometimes, then it must have a brain. But reading the sentence over and over it really seems like that's what Dr. Albert meant. That's what a brain does, it controls behavior. Therefore if you have behavior you must have a brain. (Those are my words, notice no quotations).

So let's not argue over terminology. The jellyfish have some kind of neuronal organization that produces directed behavior. But a plant also has some kind of physiological organization, albeit not neuronal, that allows it to react to its environment. How are these two systems different? NEURONS!

So this has been a bit long but here's my summation: I believe that we do not know what the word behave means. I think that if scientists are willing to apply it to jellyfish and not plants then we have a "neuron-centric" perspective. I believe that when we use the word behavior we must impose some black and white distinction between entities that do have "directed behavior" from those that do not and I believe this is a false, blurry utterly grey distinction.

I don't think there's really a moral or educational lesson here. Just something to think about the next time you use the word "behavior."

Yup!

http://xkcd.com/978/

Alive

The question of what is alive and what is not alive at first seems fairly easy to answer. Animals, plants, bacteria, etc. are living things and rocks and minerals and air are not living things. However, in science, it's never quite so straightforward (well, sometimes I guess it is but not here). Most biologists would agree that life has seven characteristics. This description may be dull but it's important for the point I want to make...I'll try to be succinct:

1. Homeostasis: your insides stay pretty constant all the time. You've got a constant temperature, for example.

2. Organization: you've got cells. You're not just made of free flowing energy or some kind of gelatinous mush.

3. Metabolism: Your cells can convert energy (food). You need to do this to maintain homeostasis and to grow and so forth.

4. Growth: yup, you started off as a single cell and now look at you!

5. Response to stimuli: Things that are alive react to the environment. Fire bad!

6. Adaptation: No one organism can do this but populations of organisms, over evolutionary time, change by means of natural selection to become better suited to their environment.

7. Reproduction: things that are alive can make more of themselves.

So that seems pretty exhaustive and it does a great job of explaining the unique characteristics of, say, an animal. Animals all eat and grow and evolve and all that good stuff. But there are some things in the natural world that look like they really should be alive but aren't and some things that seem like they really shouldn't be alive but act like they are.

Viruses are science's most notorious culprits for looking a lot like living things but not fulfilling all seven criteria. Viruses reproduce (that's what's going on when you have a cold, they're invading your cells and making more of themselves) but they can't do it by themselves; they've got to have a "host." Viruses definitely adapt, that's why everyone's worried about the potential of "super viruses," because they do evolve and (for example) become resistant to antiviral agents. They have organization even though they don't have cells but they don't grow and they don't really respond to stimuli, or at least not in the sense that we normally think of stimulus and response (even single celled amoebas and things like that look more like they have "behavior" in the way we tend to think of that phenomenon).

So scientists have been stymied over whether or not viruses are a life form or not. Perhaps they are some thing that's not life but not not alive either...maybe we just need some new language.

I've been thinking about this recently for two reasons: a friend of mine told me that scientists have observed metabolic reactions (chains of molecules processing "food" into other stuff) happening outside of "living" cells. I don't think anyone wants to claim that these metabolic reactions are alive just as is but it raises some interesting questions about how life began and how life works and what exactly the differences are between "living" and "not living."

And finally I watched this TED talk the other day. You should just go ahead and watch it. I'll wait....

I know, crazy, right?! That bit where the "cell" splits in two, essentially showing reproduction happening in a system that for all intents and purposes is "not alive" is just so cool and bizarre and throws a lot of other assumptions about cells and life into question.

Or maybe it doesn't. Maybe it just teaches us about what things on primordial Earth were like. Maybe viruses sort of do the same. Maybe 3.5 billion years ago there were lots of things that were sort of alive but by means of natural selection and competition the truly alive mostly won out. One thing is for sure: that's some pretty neat science.

Warm-Eyed?

When we first learn most categories in science we draw black and white distinctions. It helps, I think, to make broad and gross categorizations when first learning. Mammals are warm blooded. Reptiles and fish are cold blooded. These are traits that the groups mammals, reptiles and fish have.

This, of course, is really not the case. Like most broad and gross characterizations in biology these rules are broken. There are what we call "warm-bodied" sharks and bony fish, such as the blue-fin tuna. They produce internal heat in a different way from birds and mammals but they are certainly not truly cold-blooded.

While researching warm-bodied fishes for a class I'm teaching I came upon a surprising natural history factoid: swordfish are warm-blooded...but only in their eyes. Unlike the "warm-bodied" sharks and fishes the swordfish heat production is much more like a mammal's. We have cell-parts called mitochondria (you may remember them as the "powerhouse" of the cell from high school biology) in higher density, especially in certain types of tissue. These mitochondria are responsible for metabolizing ("burning") food into energy on a cellular level. When these mitochondria metabolize food one of the byproducts is heat. So by having a high density of these cell parts you get more heat.

The muscle tissue responsible for moving the swordfish's eyes are also, like certain mammalian tissue, packed with mitochondria. These specialized muscles help to heat the animal's eyes and brain. Warmer eyes mean sharper vision, great for a large predatory animal, and a warmer brain means faster processing speed, which seems great for just about any organism.

It makes me wonder why mammals and birds evolved endothermy (a general term for any organism that produces heat from within its body regardless of how that heat is produced) but fishes which have been around a heck of a lot longer only a have a few representatives with this adaptation. Will there be more warm-blooded fish in another fifty million years?

Murmuration

So apparently this video has gone "viral." If you haven't seen it...it is pretty neat:

http://www.wimp.com/murmurationphenomena/

I looked into how starlings do this. The answer being, we don't really know. This article from Wired was just published yesterday:

http://www.wired.com/wiredscience/2011/11/starling-flock/

I checked my usual science blogs and none of them had posted anything about it. Carl Zimmer, where are you when we need you, man? So the article essentially speaks for itself. The birds overall behavior looks more like boiling water than animal behavior. But what does that mean?

What I think it means is that the birds have some way of sensing what's going on with many if not all the other birds around it that we don't understand. Behaviors don't just happen so unless starlings are actually some kind of future alien robots with quantum computing capabilities in their brain that allow them to sense things free from the bonds of time and space they must be "communicating" in some way.

It reminded me, initially, of schooling fish. Fish all have a sensory organ called the lateral line (the next time you see a fish take a look at it's side: many have a visible line down the middle. Cod, for example, have a very noticeable lateral line). The "organ" is actually a series of mini-organs, pits with sensitive hair-like structures that sense pressure differentials (i.e. moving water). Because the fish can sense differences in pressure so acutely they "know" what the movement of their neighbors and their neighbors neighbors is like and can adjust their movement accordingly.

Now birds don't have lateral lines...they are derived bony fish, though, so maybe...

It reminded me of another natural history story, though. Dolphins can do something really odd. When a trainer has worked with them the human can ask a pair of dolphins to do a novel behavior together. Without making any detectable sounds the dolphins will swim to separate parts of a pool and do a behavior neither of them has ever done before at the same time. And we have no idea how this happens. We assume the dolphins must be communicating. We just have no idea how. All of our attempts at measuring the communication have failed.

We tend to assume things with animals will be nice and easy, that they won't do things that defy our recording equipment or appear more like particle physics but then something like this comes along like this. I'm betting this won't be resolved for a long while, usually some scientist has to really overcome the standard thought about how things might be working to solve a problem like this. And it'll probably be really cool science when that person comes along.

Who Wouldn't Want More Fungus?

Uff...October has been incredibly busy. So here's a picture of another weird and awesome fungus I found in the woods.

Nope, no idea what it is. It's orange, though.

Actaea pachypoda

The doll's eye plant or bane-berry is an herbaceous perrenial woodland wildflower. It's two common names come from 1) the fact that these berries seriously look like doll's eyes, making them creepy enough to be avoided. Which is good because 2) they are incredibly poisonous and would most likely kill you.

The toxin is specifically one that slows the heart muscles. Enough of it, which could be in a single berry, can entirely stop the heart.

The plant flowers in spring and is actually quite attractive, despite the creepiness of the berries. The plants grow well in loamy soil and reach about hip height. This species can be found in most northeast US forests while another species, the red bane-berry, only grows in parts of Illinois.

Epifagus virginiana

One of my favorite things to write about/teach about are organisms that defy our expectations of what characteristics a given clade should have. See my post on Monotropa uniflora, as another example. Epifagus virginiana, common name beech drops or beechdrops, actually has a lot in common with Monotropa.

Like Monotropa, Epifagus is a plant that lacks chlorophyll and leaves. This plant is also a parasite, tapping into the root system of beech trees and taking nutrients from the larger plants. Monotropa does not have a significant impact on the energy systems it parasitizes. I've had trouble finding any information on whether or not beechdrops take a meaningful amount of energy away from their host plants but given the similarities in size I imagine the beech trees they parasitize are more or less fine.

While researching this plant I learned some new terminology. This plant has two kinds of flowers: one type is known as cleistogamous and the other is chasmogamous. The former type of flower is self pollinating with stamen and style enclosed while the later refers to the types of flowers we are generally accustomed to, those that are pollinated (or that have a chance of cross-pollination through the wind or pollinators). Again, Epifagus defies our expectations of what a flowering plant should be as most of the time its chasmogamous flowers are infertile and the plant reproduces asexually (or autosexually, I suppose would be the correct term, if it exists. If not, autosexual, copyright Paul Fenton).

After the beechdrops flower they can be seen as dried stick-like protrusions near beech trees throughout winter. So you've still got plenty of the year to spot them.

Help Me ID These Insects

While camping in the Whites last weekend I found these two fairly unusual insects. Both of them had created little casings for themselves from dirt and fine gravel (I assume the insects created them themselves). So far I have had no luck IDing them. The only information I can find on any insect that does this is the caddisfly larva which is aquatic and much larger than these. My finger is in the first photo for size reference and the second shouldn't be too hard to tell either, the leaf I think was a birch or beech and is about 4-5 inches long. Any information leading to the identification of these insects will be rewarded with extreme gratitude. Check them out in the web album!

Reblog: Color and Language

OK so I'm posting at a weirdly fast pace today but this is pretty cool. Stories like this are the reason I studied neuroscience in college.

http://scienceblogs.com/pharyngula/2011/09/wiring_the_brain.php?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+scienceblogs%2Fpharyngula+%28Pharyngula%29

PZ seems to think there may be a genetic component to the difference in color perception in western people and the Himba tribe but I'm skeptical. The time since there has been any real genetic isolation seems far too small for there to be such a difference between populations of humans. I'm struggling to come up with a better example of how learning effects perception but many optical illusions come to mind. There is a whole genre of illusions that look like nonsense at first but once you "learn" what the image is it is impossible to remember what you thought you saw before. Even the classic two faces or a vase image can work this way. I imagine that color perception could involve this same kind of "gestalt" perception.

Calopteron reticulatum

While trying to ID some insects I photographed in the Whites last weekend I managed to find an ID for this insect, featured in the Drumlin Farm post a few weeks back.

Common name: Reticulated Netwinged Beetle. The post also said it was frequently mistaken for a firefly which is exactly what I thought it was at first glance. This beetle is a bit bigger though and what I caught on camera is apparently a common male defensive behavior: spreading wings when threatened. It then flew away, though...it seems like a good idea if you're being threatened by a giant photographer.

Catalpa speciosa

I’ve had this image for a while but poor Catalpa just isn’t that interesting so it’s taken me a while to write about it. If you live in the Northeast US you’ve probably seen this tree before. Its long fruits are very distinctive, giving the tree an almost tropical appearance. I shot this image at the Boston Nature Center back in August. In fall the pods, which can grow up to 40cm long, turn brown and open slightly, giving the Northern Catalpa the nickname “cigar tree.” Cause, y’know, they kinda look like cigars.

The tree can grow up to 30 meters but its crooked growth pattern limits its use for lumber cultivation. Apparently it was, at one point, used extensively for fence posts and, less successfully, for railroad ties. More commonly it’s grown ornamentally.

Another odd thing about the tree is that the leaves do not color in fall. Scientists, if my last research still holds up, still don’t fully understand autumn leaf colors (that is the natural history/physiology side of why it happens) so maybe someday this will be an more interesting fact. For now it’s an oddity to see a tree with green leaves into October or November that then suddenly depart to the ground.

Check around New England if you haven’t noticed this tree before. You’ll likely notice those long pods.

Source: EOL.org

Indoor Wildlife, Revisited

Uff, it's been nearly two weeks since I've posted anything. I've been busy, mostly with fun stuff like camping in the Whites (photos and posts to come).

One of my first posts on this blog was about finding a small spider in my house and enjoying having wildlife indoors. I know animals indoors have a wide range of reactions, even from me. A few months back we had a rat in our house which made me...less than enthusiastic...about animals inside. And this morning I found the largest spider I've ever seen!!! (Well, the largest one inside my house).

As usual you should check out the full res version in the web album to get the full effect of this image. You can really see all the hairy structures on the legs. So this spider really wasn't that big, maybe an inch diameter leg-span. But one of the things I have a healthy fear/respect of is the brown recluse spider...and I can never remember exactly what the darn thing looks like. I know they don't tend to spin webs, climb walls or do a lot of the things we typically associate with spiders but whenever I see a reasonably sized arachnid I get a bit nervous.

This is definitely no recluse but still I safely ushered this one out doors (where it's pictured). Go eat the last of the summer mosquitoes, big guy!

Animal, Vegetable, Mineral...Fungus, Protist, Cyanobacteria...

"So are those...plants? Or what?"

A question I answer a fair amount in my job. What are they usually asking about? Anemones. "Well, they're animals. They're relatives of jellyfish and corals." "OK...huh? So...how are they animals?"

This next question, the how or why are they animals question, is more difficult to answer. Anemones, fortunately eat and move so you can tell people that without having to get into the difference between a cell wall and cell membrane. Something else I find myself trying to explain a fair amount is the fact that seaweeds are not plants.

Seaweeds are protists in the family that eventually led to land plants so calling them plants is a bit like calling an amoeba an animal. The kingdom protist eventually led to all land plants, animals and fungus so it's a very diverse group that has been around for millions of years. Most protists are unicellular but things like kelp are multicellular protists. Seaweeds typically get energy from sunlight the way plants do but they have some serious structural differences. They don't have roots, leaves, stems, flowers or any of the parts we associate with plants.

The matter is further confused when you introduce the term algae. Algae is generally used to describe seaweeds (plant-like protists) that are unicellular and generally collect on surfaces (surfaces of rocks or surfaces of the water or that junk on your home aquarium). Now most algaes are protists but some are...actually bacteria. Bacteria are not even in the same family at all. They're just something, while alive, very different from eukaryotes like plants and animals and seaweed.

So why do I care about this? Well I think it's inherently interesting. But I think the reason I want to teach people about this confusing nonsense is that I believe it makes one appreciate how much more complex the living world is than you might first imagine. Whenever we talk about "animals" vertebrates get the lion's share (get it?!) of the air time. Vertebrates are one small family accounting for something like 4-5% of living animal species. Similarly, whenever we talk about animals and plants we're missing protists, which themselves are incredibly diverse, fungi, cyanobacteria, and y'know, archaea which is a whole kingdom. Archaea may not be terribly diverse, but still we're missing a whole kingdom most folks don't even know exists.

Pollen Pants!

Both places I visited last weekend, Drumlin Farm and the Boston Nature Center, had a ton of bees which is great because...well because bees are great. And they have pantaloons! If you've never noticed take a close look the next time you see a honey bee or bumble bee and see if it's got pants on. The orange spots on the bee's legs in the image are clumps of collected pollen. Industrious little critters.

Drumlin Farm

Over the last weekend I visited Drumlin Farm in Lincoln, MA. Most of the fauna I saw was of the domesticated variety but I did get a few good shots.

Drumlin farm is a Mass Audubon site and still a working farm. There is an entry fee but it's nominal. I believe it's $6 for adults. In addition to the farm part of Drumlin Farm where you can check out their woolly lambs, goats, pigs, cows and chickens (that modifier didn't carry, really just the lambs are woolly) the site contains a small nature preserve that is kept as a meadow. It's actually a pretty great place to see bugs and birds. Plus, they've got a drumlin!

What's a drumlin, you ask? Well a drumlin is a glacially deposited hill usually made of sand or gravel. Y'see, thousands of years ago when New England was all just big ol' glaciers they would slide around and pick stuff up like rocks and other sediment and carry it, sometimes for hundreds of miles. Scientists are still arguing (one of my favorite sentence beginners) about the exact formation process but it's generally agreed that the drumlins show the final movement of the glacier just as it melts. As it melts it drops piles of stones and sediment which form the drumlins. The Boston Harbor Islands are actually the worlds only submerged drumlins. Wow!

So here's some wildlife you might see if you go to Drumlin Farm:

These white butterflies are all over Massachusetts this time of year. We also saw some swallow-tail and monarchs.

The huge amount of golden rod is home to a ton of hymenoptera, most of them bees. But we also saw several wasps, including this one.

A coleoptera about to launch off my hand. It looked a bit like a firefly only quite a bit bigger. I spent a good while trying to get a decent image of this little guy (or gal) but the tall grass kept getting in the way and messing up the focus. I finally decided to just pick it up and was lucky enough to snap this milliseconds before it took flight. It's pretty cool to see the wing coverings common to all beetles spread out and it's wings ready for flying.

A goldfinch munching away on some thistle. Definitely check out the web album for an embiggened version of this. I think it's one of the best photos of a bird I've ever shot.

And of course, no trip into the wild could be complete without an unidentified weird bug. Anyone have a clue what this thing is? It would run a bit and then wave its first two legs around like it was casting a spell.

Natural History Appreciation Safety, Plus More Toads

I'm back from my trip to the Adirondacks. It was a really nice trip, got in some great hikes. However, on one of our hikes we got slightly lost in the woods. Obviously, I'm fine, I'm here typing away, and looking back everything was more or less under control. We took a wrong turn onto another trail, probably a series of canoe carries, and were very easily able to retrace our steps and get back towards our trail-head.

But it reminded me that when we start to become fairly experienced hikers we can forget the simple safety rules. So I thought I would send out this natural history appreciation PSA: even if you think everything will be fine (we did that morning) bring more water and snacks than you think you'll need and tell someone exactly where you're going and when you plan to be back. That doesn't mean "we're going somewhere around Saranac," it means exactly where. It will at least give you the peace of mind that someone knows where you are even if you aren't in any actual danger.

And now, on to the images:

A wood frog, the first of probably 60 or so amphibians we saw on this hike. I was surprised at how many more frogs and toads we saw compared to the Whites. The Adirondacks are just that much more remote and therefore that much cleaner, which keeps it a great place to be an amphibian. Poor little fellows and their permeable skin.

Some holes in a tree. Made by beetles, probably.

The hike passed by several ponds, further making the area an ideal home for amphibians. I wasn't able to get an image but we saw a mink at this one. And...

a thrill seeking caterpillar.

The first of many toads. Some kind of Bufo sp. Apparently they frequently interbreed and produce hybrid toads despite their unique mating calls.

We saw several frogs at this pond.

At this point in the hike is when the toads got really crazy. We must have seen about 40 of them in a quarter mile range or so. They were all tiny, so probably having just metamorphosed. Again, they look like some Bufo sp. or hybrids.

There really were so many that we had to be careful not to step on the tiny little vertebrates.

The next day we hiked up Mount Ampersand, one of "high peaks" of the Adirondacks. We didn't see as much fauna but the view was...pretty nice. I believe that is Middle Saranac in the image.

After coming back to the city I've had some nature withdrawal so I've been out walking and already have some new images. Stay tuned the rest of the week for some Boston natural history.

Ideas

I have been struggling to write a post recently about ideas. I know...not very nature oriented...or is it!?!?!

My "background" as such things get described by fancy academic types is technically in neuroscience which is technically a part of nature (and we all know how much Paul loves technical stuff; almost as much as parentheses and semicolons).

I have tried and failed a few times to get started and I think it might be because I was trying to make some deep point or something and not go with usual perspective of "Hey, isn't this [insert natural history phenomenon] really darn cool!"

So, without further ado: aren't ideas cool!?! I've been watching a lot of TED talks recently (if you haven't heard about ted talks check out: http://www.ted.com/talks but make sure you've got some time to kill...) and that's what got me thinking about ideas. They're really what separate us from all other organisms on the planet. We think, we have complex thoughts and we can quite easily, after a certain age, express them to one another. We've developed vast institutions and organizations simply for the purpose of talking to one another and spreading and developing ideas (read: universities). I know there's folks out there that think that there are other animals that have similar intelligence but until you show me a dolphin that philosophizes then I fully disagree that their intelligence is the same thing AT ALL.

You may ask "but, Paul, what is the point of all that philosophizing?" Personally learning and knowing philosophy has made me a happier and, more importantly, a nicer person. That's a long story and probably not appropriate for this blog. (I am trying to get back to natural history here.) But above all: like all the true bugs, chelicerates and witch hazel in the world I just think it's darn cool that we evolved this capability to describe our neurological experience with such precision AND express that experience to each other. We will probably never know the exact selection pressures that influenced our evolution towards these massive living computers and that's also kinda cool because we can imagine a plethora of situations in which we might have begun to evolve to be the smarty pants that we are.

I'm off for about a week to get some relaxin' in the Adirondack Mountains. I hope to return with some images and post ideas! As always, leave your ideas below.

Life in the Blue Hills

I finally got in my first hike in a few months yesterday at the Blue Hills, just south of Boston, and luckily I brought my camera. I found quite a few interesting organisms.

A robber fly. These are fairly large, predatory flies.

A funny little grasshopper or leaf-hopper. He's got some pretty excellent camouflage so I kept losing him but managed to get a few good shots, including this one.

Not one but...

...two toads. We've begun judging the quality of our walks by how many toads we see. So far the record is three in one walk. That was a great day. It's a little funny to think of amphibians living in the woods and the hills but that's the best place to look for them in the New England area. These are also certainly two distinct species which is pretty cool. We saw some other vertebrates: a groundhog and a ton of birds including a female scarlet tanager and a towhee.

We also saw plenty of witch-hazel, one even reaching the 30 foot range that they grow to. So now I can say with assurance that one of the places in the Boston area one can see wild witch-hazel is the Blue Hills.

But perhaps the coolest thing was this little invertebrate:

Don't see it? It's there in the bottom right of the image. It's not a great shot but this little insect was moving ridiculously fast. Here's a blown up version:

At first I thought it was a little red ant. But I'm pretty sure this hymenoptera is what is called a velvet ants. Velvet ants are not true ants but actually wasps. Though ants and wasps are very close relatives, the true ants are a monophyletic group while the velvet ants are couched within the broader family of wasps. They represent a separate transition from winged to wingless wasps and retain the painful sting of most of the wasp family.

As usual, science points for anyone who can help with IDing these critters. What a great day it was for a hike and some pretty cool New England natural history.

The Horseshoe Crab Diaries Part Four: In Which Paul Tries to Explain Why They Have So Many Legs to a Preschooler

So it's summer and during the summer my job has me working with a lot of preschoolers. I love them: they're hilarious. But in terms of science education it can be a really tough audience. I've been thinking about it in this way: preschoolers ask some of the greatest science questions but more often than not they are not developmentally/cognitively capable of understanding even a watered-down version of the true answer.

So the other day I was at an academic summer camp talking with some preschoolers about my favorite animal and one of them asked me: "why does it have so many legs!?"

I know! Why does it need all those legs? Wouldn't six or even just four be enough? Probably it would be. This is more likely than not an example of randomness in the body plan of animals. Take humans as an example. Why do we have four limbs? Because our mammalian ancestors had four legs. Why did they have four legs? Because the lobed-fin fish that gave rise to land vertebrates had four fins that transitioned to limbs as they developed adaptations that allowed them to crawl out of the water. And why did the first lobed-fin fishes have four fins? Probably due to a random mutation in the hox genes (the genes that help to control embryonic development of bodies and limbs).

The same is true of a horseshoe crab: it has ten legs because...well because it's ancestors probably did. Or because there was a random mutation in the lineage's hox genes.

That's a pretty abstract concept even for an adult. So here's what I said: "They have a lot of legs because the group of animals they belong to has a lot of legs. Crabs, insects, spiders, they all have lots of legs and so do horseshoe crabs. That's really all I can say about it!"

I'm pretty sure my answer made no sense to the little guys. I know they can do similar and different but the concept of "relatedness" among different kinds of animals I think is a little out of reach. And like I said: it's frustrating that I've never been asked this question by an adult with the background knowledge and cognitive ability to understand the answer.

Any similar stories out there? What was your biggest success helping young children understand tough science concepts?

Eww, Nature is so Gross!

Out looking for stuff to shoot I noticed something moving around in the ground. I took a closer look and found a quite large grub. None of the images I got really do it justice but it was probably an inch and a half or so long.

I'm pretty sure I've mentioned this before but I always find it interesting to think about why grubs make us instinctively nauseous and/or squeamish. There's a pretty good chance it's an adaptive reaction to finding grubs (maggots) in rotten food. If the body gets nauseous before we eat bad food rather than after it saves us a lot of energy and possible dehydration from getting sick.

Of course I can't resist staring at it and shooting it for probably 15 minutes. The thing was creating quite a stir, rooting around in the ground. It seemed like it was trying to dig or find food or both, I'm really not sure. At first I thought it was after ants but it quickly became apparent that all the ants in the area where moving much quicker than it was. Maybe it was just looking for a good spot to bury itself and do some metamorphosing. Ecdysis here we come!

Variety

I'm still here! And I've brought you more of your favorite! Cepaea Nemoralis!

One of Charles Darwin's insights into unraveling the mechanics of speciation by natural selection was that in any species there is variation. In a way it seems dumbly obvious: take human siblings. No too individuals are identical. Darwin bred pigeons so he also knew that this variation could be manipulated, in this instance by human intervention, but he took the leap to imagine (correctly) that nature could also manipulate this variation. These variations are, in essence, the stuff of evolution, the stuff of speciation. So to give you an idea of the amount of variation, in this case color variation, a single species can exhibit I went out this morning and shot a number of snails on the wall outside my house. This is what I saw:

11 different snails with 11 different patterns. Browns and yellows dominate the color variation in c. nemoralis but you can see oranges, tans, even one that was almost totally white. I wonder if there is some environmental factor but if so it must be quite acute since these are snails that were found in range of only several meters.

High levels of variation tends to be "good" for a species. It means that if the species (say c. nemoralis here) did need to start evolving towards one of these colors (say for camouflage) the genes are already present and the snails that were expressing those genes would survive more easily. Pretty quickly the ones with the "best" color would be all that was left. You might also imagine conditions in two parts of the species' range changing in different ways, one favoring one color and the other area favoring another color. That's exactly how you get speciation.

I hope to keep documenting the variation in color of c. nemoralis in our area and see if it changes year to year or season to season.

Witch Hazel and Its Galls

Uff...June is a busy month for me so I've only had a chance to post once and it was only an image. Thanks for holding in there, readers!

Witch Hazel is a flowering plant native to North America (there are two other species found in other parts of the world, however). It is so called because of the structure in the photograph which supposedly looks like a witch's conical hat. Except it's green. And tiny. And it's filled with aphids (seriously, can you get enough of true bugs?! I thought not.)

This structure is what is known as a gall. If you've ever inspected the leaves of trees with any thoroughness you've probably come across galls. They form on the leaves of many local species, especially oaks. These oak galls are generally formed by wasps. For a long time I knew of their existence but had no idea what they were.

These structures protect the developing larvae of insects and a few mites and roundworms. After the eggs of these animals hatch the larvae begin to feed on the plant inducing tumorous cell grown that forms the structure we know as a gall. The gall then serves to protect the larvae as it grows. Most of the gall causing insects are in one family of flies.

But as I alluded to above the witch hazel galls are not caused by flies but by aphids. These aphids have a very complicated life cycle. After emerging from witch hazel galls they move to feed on birch. They remain on birch for six generations but each generation produces a different form of the aphid with progressively shorter legs and antennae. After the sixth generation females are born ready to return to and lay their eggs on witch hazel, once again producing the signature witch hat gall. There is also a second aphid species that form galls on witch hazel on the stems instead of the leaves.

Kricher, John C. and Gordon Morrison (1988). Ecology of Eastern Forests. Houghton Mifflin: NY, NY.

True Bug!

Better Know an Invasive Plant: Japanese Knotweed

Japanese knotweed is an herbaceous perennial that can reach a hight of up to ten feet. It is often found near freshwater ponds and streams but can be found all over my neighborhood in yards and by roads. It develops from stalks close to the ground in early spring and by late spring/early summer is usually very noticeable in dense thickets.

Japanese knotweed is easily identifiable by its red stems:

and broad, somewhat shovel-shaped leaves:

Like most invasives, Japanese knotweed was introduced intentionally probably sometime during the 1800s. It has been used ornamentally in the Northeast United States and more recently was used for erosion control in the Northwest United States. Using non-native plants as erosion control in areas where native plants have been wiped out is an ongoing practice. Though I will assume that people making these decisions for the DCR or like organizations have done their research it still seems like a troubling practice with the knowledge of how much invasive plants have changed our local ecosystems.

Japanese knotweed is also edible and contains many valuable nutrients including vitamins A and C, zinc, phosphorus and manganese. It also contains the compound resveratol which is also found in the skin of grapes used to make red wine. This compound is what gives red wine its cholesterol-lowering properties. Research on resveratol is ongoing and many believe that it may be useful in fighting Alzheimer's and possibly even extend life expectancy.

As usual the best thing you can do to help the spread of Japanese knotweed is to try getting rid of it if you see it on your property. Most infestations can be removed manually if one is sure to remove the whole plant and bag and dispose of all parts efficiently. You may also want to encourage your neighbors and local parks managers to be on the lookout for Japanese knotweed because it can recolonize disturbed areas very quickly (are we seeing an invasive plant trend?).

http://www.nps.gov/plants/alien/fact/faja1.htm

http://www.wildmanstevebrill.com/Plants.Folder/Knotweed.html

Taraxacum officinale

Most people consider the common dandelion a weed. I can't decide how to feel about it, honestly. It is technically non-native but whether or not to call it an invasive is tough. Like all "weeds" and "invasives" it is remarkably good at colonizing disturbed soil. It can even reproduce asexually making it somewhat resilient to a decline in pollinators. That being said, it is a small, fairly unobtrusive perennial. Dandelion patches never reach the magnitude of say, garlic mustard or Japanese knotweed. And, while this can be said of several invasives, its greens are a nutritious food.

I think the main reason that I can't decide how to feel about this non-native is that our modifications of the landscape are the primary reason for its success. Without lawns and sidewalks this perennial would not be seeing the success it has today. With leaves that stay in rosettes just on the ground it quickly gets shaded out by taller plants so it needs a wide open, sunny space to grow.

If you do want to get ride of dandelions your options are pretty much herbicide alone; its hearty taproot can survive even the most rigorous gardeners.

http://en.wikipedia.org/wiki/Taraxacum_officinale

http://www.wildmanstevebrill.com/Plants.Folder/Dandelion.html

http://www.umm.edu/altmed/articles/dandelion-000236.htm

http://www.wired.com/wiredscience/2010/11/invasive-species-gallery/?pid=487