October 2010

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Well, I should have been grading but instead I did this. Not a lot of science in this one, but it does set-up an explanation of how plant cells absorb light.
Photosynthesis_pg04

This is the coolest thing I have seen for a long time. A father and son launch an HD camera into space and recover the capsule when it returns.


via Pharyngula

As I mentioned in an earlier post, there is a group of folks on campus working on an ongoing web series called Office Hours. The most recent episode is out and I make my debut as Mark Deacon, lecturer in Russian History. As you will see, I won’t be quitting my day job.

Is there anything more unnerving than the thought of a shape-shifter in our midst? Imagine consummate infiltrators that can gain our confidence and then turn on us. There are several comic book characters with the ability to beguile others with false forms. Let’s consider a classic example. In the second issue of The Fantastic Four (1961), it appears as if our heroes have turned against humanity. The Thing uses his incredible strength to tear down a Texas oil rig, The Invisible Woman disappears with a diamond, the Human Torch melts a priceless statue and Mr. Fantastic uses his elastic powers and super brain to turn off all of the power in New York.

What the heck?

Of course, by page four we discover that the fantastic foursome is being impersonated by a band of shape-shifting aliens called Skrulls.

skrulltransformationThe Fantastic Four, Mr. Fantastic and Skrulls (c) Marvel Comics and created by Jack Kirby and Stan Lee

To bad no one else knows. The newspapers have declared the Fantastic Four to be Public Enemies and our heroes have to spend the next 18 pages clearing their name, saving the planet, hypnotizing the Skrulls into thinking they are cows and putting them to pasture.  Brilliant!

cows(c) Marvel Comics and created by Jack Kirby and Stan Lee

The Thing’s line in the final panel above is prophetic. There was, indeed, worse trouble ahead.  In 2008,  47 years after the Skrulls first appeared, they were the villains in a major comic event called Secret Invasion which involved them…uh…secretly invading Earth. I didn’t read it, but apparently it did NOT end with all the Skrulls being transformed into grazing ungulates, so it couldn’t have been that good.

A whole host of other shape-shifting characters can be found in the various pantheons of four-color, spandex–wrapped power fantasies, but can any be found in nature? (Rhetorical question.) There are, of course, organisms whose shapes are meant to deceive us. Take these insects that look like sticks and leaves.

InsectMimicsA mantis that looks like a stick and butterfly that looks like a leaf. Awesome sauce!

This really is spectacular, but these critters are stuck with this particular form.  We’re looking for shape-shifters. Are there any in nature that can change to look completely different? (Again, rhetorical.)  Some, like the chameleon, can adaptively change their color to blend in with their surroundings. This is an effective means of hiding from predators and sneaking up of prey, but they haven’t changed shape. A chameleon may be hard to spot, but if we do spot him we can easily identify him as a chameleon.  We want something that can change shape and color, like the green-skinned Skrulls. Hmm. We would need something that is smart, profoundly flexible and capable of quick color changes.

Sounds like an octopus to me.

The mimic octopus is the king-cat-daddy of shape shifting. But it does something more that just look like another creature, it acts like the organism it is mimicking. This has always been the downfall of many evil shape-shifters. Sure they can look just like your dear old pal, but can they act like her? Behavioral and physical mimicry make this a truly impressive critter.

Stunning. But what happens if we expand our definition of ‘shape?’ Being visual creatures we obviously associate the identity of something by what we can see. But, for many critters vision isn’t the primary means of identifying individuals, smell is.

Consider the rove beetle Atemeles pubicollis. These little rascals look nothing like ants.  Yet, despite the lack of resemblance, the ants will treat this rove and its offspring like one of their own.  A. pubicollis infiltrates the nests of Formica polyctena and proceeds to lays its eggs there. For most insects, this would be a good way to get your babies eaten by ants. But the rove beetle larvae release an ant pheromone that tricks its hosts into thinking the beetle is family. The beetle larvae then proceed to gobble up the ant larvae with whom they are sharing a crib. They even have the hutzpah to beg for more food from the adult ants. To do so, they tap the ants mouthparts with their own to get a sugary sweet desert. When the larvae metamorphose into grown-up rove beetles, they continue to live in the nest and solicit food from the adult. Diabolical!

rovebeetle

The rove beetle is certainly Skrull-like in its ability to infiltrate and exploit, but it lacks the plasticity of a true shape-shifter because it’s stuck with one olfactory ‘shape’

That isn’t a problem for the bolas spider.

Bolas spiders eat male moths as they fly about at night looking for love.  Male moth find females not by seeing them (it is night, after all) but smelling them. Females that are receptive to mating release a pheromone perfume to announce they’re on the market. Not surprisingly, these odors are species specific since you wouldn’t want a male codling moth trying to hook up with a female greater peacock moth (gross!).  Thus, each night the air is full of specific perfume signals and the bolas spider can mimic many of them.  Using an arsenal of odors, the bolas spider sends alluring calls to males of many species who soon discover that they are looking for love in all the wrong places. She changes her olfactory shape by changing perfumes. The result is a chilling bit of olfactory shape-shifting. See for yourself.

The bolas spider’s odor mimicry is an amazing bit of chemical chicanery that should make us all paranoid. After all, who nose who you can trust?

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References

1. Holldobler, B. (1971) Communication between ants and their guests. Scientific American 224 (Mar): 86-95

2. The rove beetle figure and figure caption was taken from Alcock’s Animal Behavior (5th edition). I believe the drawing originally appeared in reference 1, but I need to check that.

3.  Stowe, M.K., Tumlinson,J.H. and Heath, R.R. (1987) Chemical Mimicry: Bolas Spiders Emit Components of Moth Prey Species Sex Pheromones. Science, 236: 964-966

4.  Bolas spider clip from David Attenborough’s Life in the Undergrowth (via Youtube)

Over on the Big Attic blog, my pals Kevin and Zander have noted that Evolution has already been made a Junior Library Guild selection.  The book won’t be out until January 4th, 2011, but apparently the advanced copies were enough to generate some notice. How could you not notice a book with such an awesome cover? Anyway, there’s more at the link above and I have swiped their scan of the official certificate!

juniorlibraryguild_evolution

I’ve mentioned the book I wrote with Kevin Cannon and Zander Cannon for Hill and Wang, right? Well, it looks like Evolution: The Story of Life on Earth is officially listed on Amazon for pre-order. Sweet. And since the Amazon entry features a picture of the cover AND I gave away promo Evolution comics at SPX this year, it must be OK for me to post an image of the cover. Right? I sure hope so ’cause here it comes. Drum roll, please….

TA-DAAAA!

evolution_cover_042710

Best cover ever, in my opinion. It contains so many terrific little details that reward the curious eye. Max and Jack looked at it for a long time. I’m pretty sure Kevin and Zander are sick of hearing my sloppy praise of their work, but I promise this will be the last time. Until next time.

(It really is cool!)

Page 3 includes the big picture breakdown of photosynthesis. As I was preparing to write this story during the summer, this is the way I broke the process down for myself. It helped me to see where material entered and left the system and the exchanges between the light dependent and independent reaction. I found the visual outline very useful. Here’s hoping my students (and you, dear reader) do as well!

Photosynthesis_03

Ta-daaaa! My last post shamed me into completing the page.

Photosynthesis_02

OK, well it looks like I can’t even do a full page a week, much less a day. I have a number of excuses this week including a 4 hour trip to the Emergency Room. All is well, but it was taxing. We were afraid Jack had appendicitis, but a CT scan showed that he was just really full of…it (something I am constantly telling him). Our doctor suggested clear fluids and a Colace and yesterday everything worked itself out, if you get my drift.

That said, I’ve had enough time to draw but I’ve been hung up on the writing. I managed to ink half of page two, but even that isn’t entirely satisfying. I’m struggling with the timing of the exchange betwen Ant Edna and Wilbur. I initially wrote the page like this (note: you might want to read the previous page again first):

Photosynthesis_half_small_no

I like it this way because the silent panel suggests the bewilderment of Wilbur and the pleading quality of Any Edne. But as I was inking, I realized I could put in the following joke:

Photosynthesis_half_small

I know, I know, I can’t believe anyone would think about it this much either. But, there you go. I can’t help myself. If you have an opinion, let me know. I’m leaning toward the latter.