Genomic Revolution

One of my favorite sites to find short, interesting videos that I can use to spice up class is TED.com.  I feel a bit like a crack dealer here by providing the first taste, but if you have never been there before, check it out and be prepared to spend the rest of the day doing nothing but clicking on video after video.  The one below is on the Genomic Revolution.  Click the video below to learn about how your life is going to change thanks to the genomic revolution.

  

Your 3.5 Billion Year Old Family Tree

One of the coolest bits about teaching students evolution is that they get to learn that they are related to every living thing.  For example, Dunkleosteus, the critter pictured above, is your 185 millionth great-grandparent.  If you take your family tree even further back you can find that you and that oak tree outside share an ancestor from about 1.4 billion years ago. 

More Climate Change Leads To Less Guacamole

For those of us who live in the midwest, the reality of Climate Change can be a bit of a tough sell.  Just yesterday, in fact, while I was in the locker room at my gym, a whole group of severely underdressed men placed one leg up on the benches and proceded to scandalize the rest of us not only with body parts that should not be as obviously displayed as these were, but also with comments like, "Where's this 'global warming' I keep hearing so much about, and "Man - I'd take a little of that so called 'global warming' those scientists are always yammering on about."

Without a decent understanding of the facts of climate change, these comments are to be expected.  This is primarily due to the fact that, unlike other parts of the country, our recent weather has been somewhat mild.  I say that having just lived through what is most likely a climate change induced polar vortex for the past several months, but for some reason cold weather doesn't really conjur up images of climate change in most people's minds.  Our relatively cool summers and, until recently, the warmish winters have not given most midwesterners a good dose of what the rest of the planet has been experiencing.  The term "Global Warming" is still commonly used and, although it is true that many places on the planet will warm up, not all changes will be in the form of higher temperatures.  Some of the changes are going to be in the form of more severe weather, some in the form of droughts, and some in the form of colder than normal temperatures, at least for a while.

And if you are a fan of the fast food-ish restaurant Chipotle, some of the changes will hit us a little closer to home.

Chipotle recently announced that, “Increasing weather volatility or other long-term changes in global weather patterns, including any changes associated with global climate change, could have a significant impact on the price or availability of some of our ingredients.”  What this is basically saying is that certain staples from the restaurant like guacamole or salsa might not be available should the price of those ingredients increase too much.  For the full story, check out Think Progress or Time  

***Update***

Chipotle is not saying that there will be a shortage of avocados this year due to climate change.  This statement made by Chipotle was part of a regular risk disclosure statement to the SEC.  All companies do this, and in these statements, companies disclose all of the possible risk factors that might affect business.  The Chipotle statement is unique in that it is the first to explicitly state climate change as a viable risk factor that could affect business.        

Evolution as a Story - Part 1

I love studying evolution.  There are many reasons for this, but one of the most compelling is that it is the story of how we, as humans, came to be.  It is a story of adaptation and extinction, success and failure, and if told correctly it can help students to a greater understanding of just how cool this whole evolution thing is.  I mean, we are related to fish and oak trees for crying out loud.  How cool is that?  I plan on writing about how I tell the story of our evolution in a future post or two, but for right now I'd like to share a few things I have made which help me tell this story to my classes.

First, I have a short textbook that I wrote for use in my Zoology class which focuses on the evolutionary story of the major groups of organisms including invertebrates, fish, amphibians, reptiles, birds, and mammals.  Each 4-6 page chapter deals with a particular group of animals and explains the main points of their evolution in what I hope is a humorous yet educational manner.  This book is available for sale as a digital download at my Teachers Pay Teachers store should you be interested.  There you can download a free sample to see what it is like as well as purchase either individual chapters or the entire textbook, should you feel so moved.  And because I am such a stand-up kinda guy, for a limited I am giving away the evolution chapter of my textbook for free!    

To supplement the textbook I put together graphic organizers for the chapters on Reptiles, Birds, and Mammals.  I give these out to the students so they can use them to take notes while we discuss these topics.  Click the links to go to my store to download free higher resolution copies of these organizers.  (The images below are just JPEGs because I am relatively new to blogger.com and haven't figured out if it is possible to link files to posts.)  

Finally, I have made Prezis which use the graphic organizers as the main focal point to help the students follow the story we are discussing.  The links to the Prezis are below.  If you are a regular user of Prezi, feel free to make a copy of these presentations for use in your classroom.  If you are not a regular user of Prezi, it is an amazing, free, online presentation tool that I can't recommend highly enough.

Reptile Evolution Prezi Link

Bird Evolution Prezi Link

Mammal Evolution Prezi Link

New Video Series from PBS - Your Inner Fish

I am more excited than I probably should be for this new series from PBS.  "Your Inner Fish" is one of my favorite evolution books and now PBS and the author, Neil Shubin, have teamed up to make a 3 part series on the subject.  It is slated to start on April 9 at 10pm Eastern/9pm Central.  Check out the website for more information and a few videos.  

Boy, wouldn't this be terrible?

Major Transformations - Jaw Evolution

I like my jaws.  They are, perhaps, my favorite thing to use when I am chewing stuff.  They are also incredibly helpful in the whole talking department, and given that I am a teacher this is a fairly important adaptation for me to have.  Jaws are really swell.

But how did we come to have these neat little chompers anyway?  It turns out that the story of jaw evolution is fairly simple.  You see, once upon a time about 530 million years ago, there lived a group of critters named the Agnathans.  These were a strange sort of organism what with their long bodies and sucker faces and no paired fins, but they were some of the first fish to grace our fair ocean and for this we have to give them credit. 

They were a happy sort of fish (I assume) and lived their lives happily filtering their breakfasts, lunches, and dinners through their happy little sucker mouths.  The water would flow in through their open face hole and then out again through the gills.  This provided them with both food and oxygen which are good things to have if you want to not die.  And not die they did.  Or didn't.  Or didn't not do.  Or whichever combination of words means that they survived for quite a long time and can, in fact, be found alive today.  The relatively gross Lampreys and the downright vile Hagfish are both examples of Agnathan (jawless) fish.

Those little gills that they used to pull oxygen from the water are all feathery and frilly and, if taken out of the water, will collapse in a little less than frilly pile.  To combat this, these jawless fish used special cartilage bars called Gill Arches to give the gills a bit of backing.  These gill arches served the purpose remarkably and kept those little frilly gills open and extracting oxygen, but the relative stiffness of these gill arches could also be viewed as a bad thing.  Since they couldn't flex too much the fish had to rely on continuous movement or the occasional currents to keep water flowing over their gills.  

This constant motion was a major energy drain and could have been a bit of a problem for these early critters.  No matter how streamlined you are, constant movement is going to require more energy than simply hanging out.  If you will allow me a bit of gross oversimplification, after a bit of time a mutation or series of mutations in the genes that regulate the formation of these gill arches came about and, quite literally, changed the world.  The gill arches became hinged so that they could be a bit more flexy.  This added flexibility gave those critters with these mutations an advantage over their less flexy peers.  They could now pump their gill arches like a bellows and bring flowing water over the gills without having to move around much.

So now we have flexible gill arches.  You might be asking, What does this have to do with my ability to eat a cow?  Actually, it has everything to do with your ability to eat a cow, or celery, or anything else for that matter.  You see, it was these flexible gill arches that eventually became the jaws.

In another gross oversimplification, over time the front gill arches became more flexible and pushed forward a bit.  The flexible gill arches in the front linked up with the mouth and gave the fish a tool for trapping food.  Now the fish could flex the rear arches to bring water into the mouth and over the gills, and it could flex the front gill arches to snap completely shut to catch other critters for food.  The jaw was now basically complete - an apparatus for taking oxygen out of the water was turned into a weapon.

For a more complicated version of these events complete with fancy science words and a lot more detail, go here.