Wednesday, November 2, 2011

Relatives for dinner! Natural selection at it's finest...



In class we have been discussing evolution lately. Specifically, we have discussed Darwin's mechanism for evolution or natural selection. Basically we can sum up natural selection in five points; nature produces more offspring than can survive, the environment is hostile, there is variation among offspring, some traits provide organisms with an advantage, and each generation has more offspring with the beneficial traits. In order for natural selection to work, the organism with the most beneficial trait has to reproduce and pass that trait on to it's offspring. Imagining that there are many ways in which an organism can do this, I think you will be surprised to consider the one highlighted in the article 'A Toad-Eat-Toad World,' and other Tales of Animal Cannibals by Natalie Angier. Yes, you read the title right. How about ensuring your right to mate by consuming (literally) the competition.
Angier tells the tale of cannibalism in several different species, focusing initially on the cane toad. Now you may be asking yourself, "how can this benefit the toad in terms of natural selection?" Three possible "motives" for the cannibalism are described as follows:

  1. Tadpoles feasting on the eggs will speed up their own maturation. Eggs are packed with nutrients, so think of it like a high energy drink. 
  2. If the eggs are allowed to hatch and develop they will just be producing future rivals for food, shelter, and mates. By sitting down to dinner with a relative (evolutionarily speaking), the tadpoles are eliminating the competition before it exists. Truthfully, even of the eggs came from the tadpoles mother, who knows what male actually fertilized them. The fact that their mother has little discretion in choosing her mates means they are not dining with on a full blooded relative.
  3. Since the cane toads produce a toxin that most other animals can not eat, the eggs become a food source that is not available to other species.

So how does this relate to natural selection. Keep in mind that at it's foundation is the idea that organisms with beneficial traits must pass them onto the next generation. In order to do that, they must reach a reproductive age and produce offspring. Through cannibalism, they are essentially eating their way to their mates hearts.

The cane toads are an interesting species, and not just because of their family dinners. Cane toads were introduced into Australia in 1935 to control the cane beetle. As with many introduced species this has turned out to be a disaster. With very few native organisms that prey upon the cane toad they have quickly overpopulated and reduced the populations of other organisms with which they compete. Needless to say, they did little to stop the problem for which they were introduced. Especially since the cane toads can't jump high enough to eat the beetles living on the cane stalks. I suggest reading the Wikipedia article about their introduction to Australia for more information. 

Watch the following video to see just how Australia is dealing with the problem of this introduced species:



I'll end with this... would you believe that there are people that actually lick these toads because of the hallucinogen effects from their toxins? The same toxins that are the reason they have very few predators in Australia. Toxins which can potentially stop your heart! Of course you would, people do dumb stuff all the time. Well toad lickers, there might be hope for you yet! Bart Currie from the Menzies School of Health thinks he might be able to find a treatment for the poison in the slatey grey and keelback snake venom. After all, these snakes can consume the cain toad. Even if he does, how desperate and low must you be to have to lick a toad to have fun. Hopefully, cannibalism will not be necessary to ensure these people don't pass their genes on to the next generation.
 


Wednesday, October 19, 2011

How big is your footprint?

As we have moved through the beginning stages of studying environmental science, a recurring topic has been our ecological footprint. We watched the movie The Human Footprint and saw first hand just what our individual impact is on the Earth. This movie provided a visual of the stagering quantities of goods and services those of us living in the United States consume during our lifetime. We have also discussed the very real fact that developed countries use 75% of the world's resources even though we make up only 20% of it's population. What does that mean exactly for the 80% of the world's population that live in developing countries? Essentially, that in order for us to maintain our lifestyle of privilege they have to remain poor. Is that fair? What can be done?

The inspiration for this post came last week while I was browsing Twitter posts about education. One post directed me towards a pretty unique video. The video was for Sarah McLachlan's single World on Fire. The song itself is very inspiring. According to McLachlan, "The song is about trying not to feel paralyzed when we see all that is wrong with the world, and remembering that even the smallest gesture can make a difference - corny but true." The video was made with donated labor, and as you can tell from watching, very little in terms of flash and glam. The most poignant part of the video is the captions and pictures interspersed throughout. The video gives the standard rates for various production costs and then explains how the money was actually spent. After watching the video, you can learn more about the motivations and inspirations by visiting this page on the Media that Matters website. It says so much that McLachlan used her wealth to make a difference rather than make an over the top music video. One that would have probably diluted the meaning of the song anyway.



Of course this isn't the first time that Sarah McLachlan has used her star power and unique voice to support a great cause. Most of you will probably remember this commercial she did to fight animal cruelty.



There is no doubt that McLachlan is doing great things, but what about us? We make choices everyday that impact our world and it's resources. A year ago I stopped using plastic water bottles. No longer am I buying those thirty packs of spring water from the grocery store on a weekly basis. Instead I am using an incredible water bottle made by Thermos. I normally only need to add ice three times a day, and regardless of how many times I fill the bottle, I always have cold water. Of course, it is easy to make mistakes. I bought the fish the other day in the cafeteria for lunch. I asked them to put it on a plate for me instead of a tray to avoid leaving the cafeteria with one of the lunch trays. Thankfully there was a diligent environmental science student there to point out the errors of my way. The plates unfortunately end up in a landfill, where as the small effort of returning the tray saves this needless waste. I will not let that mistake happen again!

In addition to the small ways we can reduce our ecological footprint, there are other ways we can help as well. I thought this was a great time to explain why my environmental science students are required to follow the Sustainable Thoughts Blog. Michael Despines, the blogs author, is a former graduate of Hanover High School. Through this blog he shares his thoughts on moving towards a sustainable future in the United States. He has also developed a wonderful lecture, The American Dream, The Worlds Nightmare, which he delivers to high school students, college students, and I assume basically anyone who will listen. He is amazingly well traveled and has led a pretty amazing life. I strongly suggest my environmental students spend some time looking at his blog for inspiration as they look for topics that interest them about environmental science. Additionally, Mr. Despines is also an incredible photographer. Along with his advocacy through writing, I am sure his photography also inspires his viewers to treasure this wonderful planet. I will leave you with a current image from his photography website and a question. How are you reducing your footprint?

Michael Despines Photography

Thursday, October 6, 2011

An Apple a Day...





“Your time is limited, so don't waste it living someone else's life. Don't be trapped by dogma — which is living with the results of other people's thinking. Don't let the noise of others' opinions drown out your own inner voice. And most important, have the courage to follow your heart and intuition. They somehow already know what you truly want to become. Everything else is secondary.” - Steve Jobs, Standford Univerisity’s Commencement Address

Without a doubt the world lost a leader of innovation and creativity this week with the passing of Steve Jobs. He was responsible for bringing us the personal computer, the mouse, the iPod, the iPhone, the iPad and many other "magical" technologies. So many of which have inspired us, helped us learn, organized us, and simply made life that much more enjoyable. Apple is a company that has provided us with many amazing products, ones that have had amazing impacts on our everyday life.

How have those same products impacted our environment? If you visit the Apple website you will find a page devoted to Apple’s environmental footprint. Being an Apple fan, and of course an environmental science teacher, I am happy to say that once again Steve Jobs is a leader in the things that matter. Apple has seen a growth in revenue of 74% since 2008, however their greenhouse emissions have only grown by 57% during this time. They are also the only company in their industry to exceed the ENERGY STAR specifications. Apple has gone to great lengths to use less materials in their products, remove toxic substances, manufacture responsibly, reduce packaging materials, make energy efficient products, use recyclable materials, and create products that last longer.


Steve Jobs set out to create products that consumers love. There is no doubt that he was successful. In addition to providing us with wonderful products we love to use, Apple has continued to look to the future and manufactured products in an environmentally conscience way. Giving us the products we want, from a company in which we can be proud.

At least that is the picture painted by on Apple’s website. In April 2011, the website Appadvice.com published a story in which Greenpeace accuses Apple of being one of the worst environmental offenders in the tech industry. Greenpeace ranked Apple dead last in their reliance on coal, claiming that 54% of its energy is obtained from this dirty energy source. In contrast, the article later quotes Jonathan Koomey, a project scientist for the End-Use Forecasting Group at Lawrence Berkeley National Laboratory, as saying that downloading music over buying it on a CD reduced emissions from 40 - 80%.

There is probably little doubt that Apple is not as entirely environmentally friendly as their website would have you believe. Of course when you take into consideration the raw materials no longer needed to create audio cds, movies, and books we can now enjoy as digital media, Apple has certainly changed the way we interact with and enjoy the things in life that move us. Maybe this is one more way that Steve Job’s has made the world a more enjoyable and environmentally friendly place.

Watch this old but inspired Apple TV ad from a long ago campaign. Should Steve's picture be included in the mix?