Mr. Stevenson's Zoology Homepage
If you need to find me:
Zoology Room 272
Online Component of the Hexapod Mouthpart Lab
Check out the Zo Fakebook pages
Please give me some feedback, which capture the essence of facebook the best and which covers the anatomy, ecology and life cycle of the chosen animal the best.
More to come as I get the links.
The Gumboot Chiton
This beast is awesome for at least 4 reasons.
1. The teeth on their radula are made of the hardest biomineral found on Earth.
2. The biomineral is magnetite which means their teath are made of iron and are magnetic.
3. The growth process of the chiton teeth has been exapted to grow minerals for solar cells and batteries. Read about it here. Below is an image from the publication highlighting the radula.
4. Because of its appeance the gumboot is commonly called wandering meatloaf.
Revenge of the Herbivorous Spider!
You've heard me say that for every rule in biology there is a herbivorous spider... well here we go again. In evolutionary biology there is a concept called Dollo's Law which basically says evolution does not backtrack. This is accepted as true in a general sense, but it's details have been the subject of some spirited debate. Richard Dawkins and Stephen Jay Gould both weighed in on the subject.
New research indicates that dust mites evolved from obligate parasites that in turn had evolved from free living ancestors.In this case it appears as though Dollo's Law has been violated.
I'll let you decide...
Read the details at ScienceDaily.com: http://www.sciencedaily.com/releases/2013/03/130308093424.htm
Sorry for the misleading post title, but Revenge of the Formerly Free-Living Then Parasitic but Now Free-Living Again Dust Mite doesn't really roll off the tongue...
Metazoan of the Week 03/11/2013
Not Just Tasty... Actually Gluing Internal Incisions Together!
Bioadhesives have been growing in use in the past few decades, but most adhere only poorly to wet surfaces... Kind of a drawback considering that all of your organs are moist. Scientists at PENN STATE and University of Texas have developed an injectable synthetic polymer based on the mussel's adhesive proteins. They can even control how quickly it degrades in the body by tweaking the formula. Is there anything Molluscs can't do?
My Recommended Reading List Has Moved!
See the sidebar for link.
Metazoan of the Week 02-26-2013:
The ELECTRO-pod! (cool theme music goes here)
Scientists have implanted an electric fuel cell in this snail that enables it to generate electricity! The fuel cell opperates with electrodes made of carbon fiber that have been coated with two different enzymes. One electrode pulls electrons from glucose and the other uses those electrons to turn oxygen molecules into water. What is essentially happening in the fuel cell is a process analogous to cellular respiration with glucose providing the enegry to generate electricity instead of concentration gradients in mitochondria and large amounts of ATP.
Metazoan of the Week 02-18-2013:
Nematode Worms aren't all Ghastly, Infectious, Parasitic Beasts
One study found that infection with certain hookworms can improve healing of wounds. Sounds counterintuitive... How can an infection improve healing? Read the details here and BONUS! the research work was done at UMDNJ.
What do you call it when your parasite's parasite is also your Black Plague? Some call it a miracle in the fight against the invasive formosan termite in the southern US. Details are here.
A nematode may help the fight against cancer. Nematodes and humans share a tumor suppressor gene. In humans it is called pRb and in nematodes it is LIN-35. "This research is important because it offers possible new ways to shut down the genetic machinery that contributes to cancer growth and progression," said Mark Johnston, Ph.D., Editor-in-Chief of the journal GENETICS. Details are here.
Look at the awesome caterpillar soup pouring out of that thing! In an awesome reversal from the Leucochloridium worms hijacking snail brains and making the snail's eye-stalks look oh-so appetizing, Heterorhabditis worms cause their host to look less and less appetizing as they reproduce and take over the host system. AND I think I found my answer to the question above... the bacteria is a mutualist with the nematode and they represent a parasitic tag-team. The worm gets the team inside the caterpillar, to craft an analogy the worms are the lock-pick expert, and Photorhabdus luminescens (the bacteria) is the demolitions expert. P. luminescens quickly soupifies the caterpillar resulting in perfect nematode food. A trip through a bird digestive system is the end of the line for the nematodes, and the bacteria can't live without their lock-pickers. The tag-team conspires to "paint" the caterpillar bright red and make it glow slightly. As the color changes the caterpillar becomes less and less attractive to birds... and this is a huge selective advantage for the tag-team... Now the bonus coolness: the glow has been reported in soldiers' wounds dating back to the US Civil War. And the "angel's glow" helped them recover better than the soldiers who did not glow in the dark. Read a more complete rundown of red glowing caterpillars HERE, and check out the authors awesomely titled blog: Not Exactly Rocket Science.
OK, OK, one beautifully infectious, parasitic, beast nematode:
Metazoan of the Week 01-21-2013
(Back after a long hiatus, my apologies)
I tried to find some information and got largely nothing. It is small and brightly colored. I found zero, nada, zilch on it's food sources, toxins or predators. I think they might be Miami Marlins fans....
A large Pseudoceros susanae would be 5.5 cm (that's about 2 inches for those who have not switched to the metric system, I'm look at you America)
Pseudoceros susanae means Susan's Pseudoceros and is relatively new to science. It's name and description were recognised in 1997.
As Per Request: Porifera PowerPoint
Metazoan of the Week 12/17/2012
The harp sponge: Chondrocladia lyra.
Watch this! It will give you an insight into the life and ecology of this crazy beast. We have really just begun to scratch the surface of the diversity that we discover in the deep ocean. This thing really seems like alien life on our own planet.
SpongeBob by Request
Development Video for the Absentees
I am looking for a new file hosting site that works quickly and easily. I'm exploring Dropbox and a couple other options. Opinions are welcome. Help a guy out. Details and link will follow, check back frequently.
Metazoan of the Week 12/10/2012
We have been discussing developmental biology this week and mentioned the developmental pattern of crocodilians. Crocs are somewhat unique in the fact that they grow throughout their life, until the day they die, with no real maximum bound. The largest saltwater crocdile ever captured is named Lolong and he is absolutely huge.
Lolong is 20.24 feet long and weighs 2,370-pounds. Enormous doesn't really capture the reality of this beast. You can read more at NatGeo News HERE. I tried to find the pic with the best perspective on size so you can appreciate the immensity of this crocodile. Here's a pic showing four guys using the unofficial measurement unit of "dudes" Lolong is four dudes long. The dude is not general recocognized in the science community, but I think we can agree that any crocodile four dudes long is a biggun. On closer inspection, Lolong apears to be just 3.7 dudes long, but I'm not sure they followed official dude measuring protocols. What do you think?
Metazoan of the Week 12/03/2011
The Club Winged Manakin Machaeropterus deliciosus. This is a stop motion photo of a male making music with his wings! In a fashion similar to crickets the manakins rub their wings together to make sounds that attract potential mates. The noises are incorporated within elaborate courtship dances.
Photograph by Tim Laman, National Geographic
Here is a video (of a few different manakins) that includes footage from highspeed cameras. I apologize for the kooky bird biologist reenacting the dance.
Here is another piece of video of the red-capped manakin from NatGeo's World's Weirdest, no bird biologist this time, but no high-speed cameras either.
Ecological Relationships Video From Class
For those that need it, the video is HERE Let me know if you have any problems with downloading or play back.
Awesome I say!
Not sure how many of you will agree with me... but the video below is awesome. It is pig carcass being skeletonized on the bottom of the ocean. Lot's of sea lice, some shrimp, and one inquizitive visitor at the end. Watch!
Metazoan of the Week 11/26/2012
The relatively recently discovered (2011) pancake stingray Heliotrygon gomesi:
"Big Deal!," you say. "It's a sting ray that looks like a pancake...," you say. "Well check out the next pic!," I say. Scroll down to end the suspense.
A x-ray image of Heliotrygon gomesi:
"I didn't think it would look like that!" you say. "There is more than just what meets the eye," I say.
More at NATGEO
I'll apologize in advance if this rambles... It is just a collection of Thanksgiving thoughts.
I'll bet you didn't know Turkeys were domesticated at least ~2000 years ago. There is evidence of Mexican turkeys in ancient Mayan settlements. This finding pushes the domestication date for turkeys back about 1000 years. Usually it is though that turkeys were domesticated by ancient Aztecs in Mexico, but the discovery of turkey bones with signs of domestication changes in Guatemalla alters the story of turkey domestication significantly. Article is here: http://www.sciencedaily.com/releases/2012/08/120809090706.htm
Here is new potential job for some of you: Paleopathologist. This field is a mash up of archeology, pathology, and garbology. Paleopathologist Brooklynne Fothergill researches discarded remains of domesticated animals from garbage dumps of the past to uncover how people of the past farmed, ate and cooked the animals. Traditionally animal remains from archeological digs were over-looked in favor of human made artifacts, but there is a reservoir of information written in the bones of the past. As she has made her studies Fothergill has been assembling sort of an unofficial chronology of the turkey within civilization, and the role the turkey played in native american and colonial life. The Article is here: http://www.sciencedaily.com/releases/2010/12/101222071825.htm
Here is list of things I'm thankful for (that most people don't every think about)
During period 3 today we discussed face blindness at the beginning of class, I don't remember how it came up, but the neurologist I mentioned is Oliver Sacks. Here ia link to an interview with Oliver Sacks http://www.economist.com/blogs/prospero/2010/12/biology_and_biography topics from faceblindness to real blindness. Very interesting. If you have more questions about faceblindness you may want to read his book "The Man Who Mistook His Wife for a Hat".
Metazoan of the Week 11/19/2012
The flamboyant cuttlefish Metasepia pfefferi:
Based on the coloration I'd suspect toxicity in someway, but I haven't researched it yet... I'll report back when I have a minute.
Here is an excerpt from the transcript of PBS NOVA's episode called "The Kings of Camoflage."
Back at Australia's Institute for Molecular Bioscience in Queensland, Mark Norman is about to find out if the colorful flamboyant cuttlefish is truly poisonous or just a poser.
MARK NORMAN: That's worth looking at.
Toxicity is really rare in these sorts of animals. There's thousands species of octopus, squid and cuttlefish, and in all the world, there is only…blue-ringed octopuses and, just recently, the little striped pajama squid are the only ones that are known to be, to be poisonous, to be very deadly. And so, trying to understand the behavior of this strange little cuttlefish, I think it's really important that we find out whether it's pretending to be something else that's dangerous or it itself is dangerous.
NARRATOR: Toxins could be anywhere, from the skin to the inner organs. If the flamboyant's bite is toxic, its saliva will contain the poison, just as in the blue-ringed octopus. But it could also be mixed with its ink. Mark needs to analyze all body parts.
And the results?
MARK NORMAN: Well, it turns out the flamboyant cuttlefish is toxic. It's as toxic as blue-ringed octopuses. And blue-ringed octopuses have killed humans from their bites, so we've got the first deadly cuttlefish in the world. And it's amazing on a couple of levels. First of all, it's actually poisonous flesh, the muscles themselves are poisonous. So this is the first time that flesh that is deadly has been reported in any of these groups of animals. And secondly, the toxin itself is not known. It's some completely different class of toxins. And toxins like those could be the key to whole new discoveries for lots of human medical conditions.
NARRATOR: But beyond any potential medical use, the toxin is exciting to Mark because it helps explain the flamboyant cuttlefish's oversized confidence.
MARK NORMAN: This is a fantastic result, because it makes sense of what we're seeing in the wild. And this toxicity, this poisonousness is probably what's underpinning the whole weird behavior of the animal. And the fact that a group of animals that normally swim around or spend a lot of time trying to be camouflaged, have become so obvious, have given up swimming, are walking everywhere, it's like a major step towards a whole new line in the evolution of these animals.
So it is toxic... I'll track down some video of the described behavior.
Yawning IS Contagious
The coincidences pile up this week...
During period 3 today we were doing a little comparative anatomy of the middle and inner ear in whales and humans. I mentioned yawning as the best way to open one’s Eustachian tubes and relieve the phenomenon usually called "my ears are popping." This mention of course segued into my usual discussion of contagious yawning; I just discuss the scientific study of yawning which indicate the contagious nature of yawning is not about yawning itself, but coordinating social behavior by yawning and you don't even need to see a yawn, or a person yawning to start the yawn contagion. You can just hear the word yawn or yawning and it may trigger a yawn, and the more you hear yawn or see a yawn the more likely you are to yawn. In fact as I write this and think yawn I have the urge to yawn, but I'm suppressing the yawn because it will wreck my flow in writing about yawns and yawning. Now it is not every day that we discuss yawning, but we did yawn, I mean discuss yawning today and the majority period 3 yawned while we discussed the social aspect of yawning and yawn contagiousness and so we got some first-hand anecdotal yawning data about yawning as a tribe... I could go on but I've used yawn or yawning in this yawn paragraph 31 times to let you understand the contagiousness of yawns (32). I should move on and let you know that I found a VERY recent article on yawning (33) in bonobos. Researchers discovered that yawning (34) is contagious in bonobos as well as in yawning (35) humans. AND that contagious yawning (36) is more common if the yawning (37) bonobos are related to the other yawning(38) bonobos, which tends to strength the yawning (39) social coordination hypothesis for a yawn(40) contagion of yawningness (41). Here is the link to the Yawning (42) article about bonobo yawns, and tell me, did you yawn while you read this rambling treatise on yawns and yawning and yawning as a way to coordinate social behavior, and yawn contagiousness? I would now like to claim the world record for using the word yawn, yawning, or yawningness the most times in a single paragraph. Please forgive my grammar, I was concentrating on yawns and yawning and suppressing yawns. I think I’ll go yawn now. Too bad there is no one here to yawn with me. It would be nice to feel part of a group with some nice social yawning… Maybe my kids will yawn with me later… Interesting fact: the yawn impulse from hearing the word yawn is not present in kids less than 5. Try it on them… All you need to do is use the word yawn or yawning as many times as possible while you talk about yawns and how yawns are contagious. I tried it on my son when he was five and I got him to yawn, and then he turned the tables on his old man by chanting “yawn, yawn, yawn, yawn, yawn, yawn, yawn, yawn, yawn, yawn, yawn, yawn, yawn, yawn, yawn, yawn, yawn, yawn, yawn,” endlessly in the back seat. I have never yawned so much in my life. But anyway, read the yawning article, it may even make you coordinate your behavior with yawning bonobos. How many yawns was that? I lost count.
Carl Zimmer IS "The Man"
Carl Zimmer recently (Nov. 11th) wrote a blog post at The Loom about Herman Melville's Moby Dick and a somewhat neglected chapter on Cetology. Odd that we have been discussing systematic and classification and there is Carl Zimmer exhibiting a mind meld with us. He has linked to an audio reading (redundant?) that wasn't working for me but here is the direct link: http://soundcloud.com/moby-dick-big-read/chapter-32-cetology-read-by.
And while on the topic, American Association for the Advancement of Science has just announced this year’s Kavli Awards for Science Journalism. Guess who has won for the third time and is now no longer eligible.
Metazoan of the Week 11/12/2012
After a two week hiatus for storm damage, the metazoan of the week is back and we need to go big. And by big, I mean small, but so cool we need video. I bring you a double feature of the velvet worm!
Characteristics of Life Writing Assignment
Assigned 11-12-12 Due 11-19-2012
OK Attempt number two at writing an argument for your personal definition of life.
Assemble your definition of life for the resource material you have available.
In addition to Zo reading #01 use these 3 sources:
Take the time to analyze the source material. Decide if you are a lumper or a splitter. AND then argue and counter argue. be prepared for the person who says you forgot something or generally disagrees with you.
The focus here is clear consice writing - NO FLUFF. Write a solid intro explain the dificulty associated with defining life. Then define life for yourself while accounting for the differences in approach from your four sources. Focus on your thoght process for why you have included the characteristics that make sense for you. If you choose to exclude a characteristic from one or more authors you should describe your reasoning in that regard also. Your final paragraph should be a discussion of what you learned from the process, this can be personal, but maintain the NO FLUFF attitude. Did I say, "NO FLUFF?" I'm sorry, I meant to say, "NO FLUFF!!"
Here is the link to the Zimmer article from class today http://txchnologist.com/post/30814235711/can-a-scientist-define-life follow the links embedded in the work to see the discussion and argument among Trifonov, Popa, and Szostak.
Strange Days Indeed 11-08-2012
It will take some time to get back to normal... Just hoping all of you are safe and warm. I will be posting an adjusted schedule when I know how the district will be handling the calendar of school days. Check here often... provided you have power and internet, sorry about that...
The calendar plan (as I understand it) it to give up presidents weekend and add one week to the school year, and we are all good. Spring break is intact and we still have snow days. Quite an easy fix.
Now here is a music video of musician I know from growing up in the Philly area...
Strange Things are Afoot at the Circle K
Today we were talking aboout naming taxonomic groups and here is an article title from Science Daily that I stumbled across this afternoon: Nineteen Species of Fern Named for Lady Gaga; Researcher Says the Inspiration Was Literally Written in the DNA Sequences .
The coinsidences stack up. Check this out:
She is wearing a fern gametophye! It is a crime against fungus I say.
There is more...
The fern's DNA sequence is filled with GAGA repeats.
I need to go to my happy place and think warm thoughts... I think I'll watch Monster Bug Wars, or Monsters Inside Me.
Oh, here is the link if you really need to check it out http://www.sciencedaily.com/releases/2012/10/121023112521.htm
Teddy Graham Lab Mach 2
The website provider's scripts and Java embeds are being really sketchy. I can't upload and manage my documents right now, or all evening for that matter, my appologies.... We will deal with it tomorrow.
Metazoan of the Week 10/22/2012
Two for the price of one!
Images courtesy of and copyright Alexander Wild http://www.alexanderwild.com/
What we have here is an ant and a spider mimic. Which is Which? Respond below...
Answer will follow soon. Vote Now!
↓ Look! ↓ ↓ Fancy! ↓
Animated version of the PowerPoint Content of today. Enjoy!
Metazoan of the Week 10/15/2012
This species of Chinese soft-shelled turtle (Pelodiscus sinensis)
...wait for it...
Urinates with its Mouth!
Before you are entirely repulsed, this is ahighly adaptive characteristic that has enabled these turtles to successfully colonize brackish and saltwater environments. Scientists think researching this lovely behavior may enable them to help people suffering from various forms of kidney failure.
Consider the posibilities...
Don't take my word for it... Read the full article from National Geographic News: HERE (Float over the link before you follow it and look at the terms NatGeo used in their URL. Hillarious!)
I'm thinking that this would not make the best superpower for your alternative final exam option #6
Try out EvoDots!
The Tutorial is HERE.
The EvoDots Application for Windows is HERE.
The EvoDots Application for Mac is HERE.
Make sure your read the tutorial information and follow the rules to make the simulation work. Please report back to me your experiences.
Clarifying the Teddy Graham Assignment
The final draft of your Teddy Graham procedure will be due Wednesday 10/10/2012.
Here is what I need you so submit:
1. Your original lab handout with all questions, data, and graph. This should include the first draft of your modified procedure. This was originally due Monday 10/01/2012
2. The second draft of your modified procedure, pursuant to our discussion of questions 4 and 5. This was originally due Wednesday 10/03/2012
3. The third and final draft of your modified procedure following your group discussions and feedback.
YOUR GOAL IS TO MODEL NATURAL SELECTION AS ACCURATELY AS POSSIBLE WITHIN THE CONFINES OF A SNACK CRACKER TEST SUBJECT.
DON'T GET LOST IN NONSENSE!
EYES ON THE PRIZE PEOPLE!
I AM TRYING TO ASSESS YOUR KNOWLEDGE OF NATURAL SELECTION WITH THIS!
Sorry for yelling, I just worry about you guys. Remember Rule #2: Put Learning First.
There is a cool mollusc down there ↓ check it out!
I've archived the earlier posts to make the page faster you can find them over there → If you need to reminisce.
I have a new philosphy of teaching. I am calling it the Escalator Philosophy of Teaching. Before I elaborate, please watch this:
The Escalator Philosophy of Teaching: I can enable and assist students to the point of helplessness and they will become the people “trapped” on the escalator, waiting for me to run to their side and sweep them off of the escalator –or– I can place students in situations where they must analyze situations, mobilize prior knowledge, evaluate possibilities, and create contingency plans for themselves, so they can get off the escalator without my direct assistance.
Which path should I choose? Decisions... decisions.
What's the deal with zebra stripes?
I'm asked over and over again, "Are zebras black with white stripes or white with black stripes?" I usually respond with "Yes," and my students are left unsatisfied. It just always seemed like a trivial piece of jeopardy information...
I'm also frequently asked about the adaptive significance of zebra stripes. My usual answer has to do with motion camouflage and breaking up individual outlines, and there is evidence of passive cooling/ventilation of the zebra due to differential heating of the stripes and the production of micro-winds.
I have discovered that I was mostly wrong about the adaptive advantage of striping. And I also have the answer to the black with white -or- white with black conundrum.
I'll share the answers with you: FOLLOW THIS LINK
What is the importance of, or rationale for, writing lesson plans? Writing lesson plans can be time consuming. It can seem like a daunting task to continually