Category: Natural World

Oil does not come from dinosaurs.

Phytoplankton (image from NASA).

There’s a nice article in the New York Times on the fact that oil, petroleum, did not come form dead dinosaurs, but rather from the microscopic plankton that died and fell to the ocean floor.

The idea that oil came from the terrible lizards that children love to learn about endured for many decades. The Sinclair Oil Company featured a dinosaur in its logo and in its advertisements, and outfitted its gas stations with giant replicas that bore long necks and tails. The publicity gave the term “fossil fuels” new resonance. – Broad, 2010

It’s easy to forget how pervasive is the idea that oil comes from dinosaurs. Broad’s article is a nice reminder that:

Today, a principal tenet of geology is that a vast majority of the world’s oil arose not from lumbering beasts on land but tiny organisms at sea. It holds that blizzards of microscopic life fell into the sunless depths over the ages, producing thick sediments that the planet’s inner heat eventually cooked into oil. It is estimated that 95 percent or more of global oil traces its genesis to the sea. – Broad, 2010

How do we know?

[I]n the 1930s. Alfred E. Treibs, a German chemist, discovered that oil harbored the fossil remains of chlorophyll, the compound in plants that helps convert sunlight into chemical energy. The source appeared to be the tiny plants of ancient seas. – Broad, 2010

Phytoplankton bloom off the Carolina coast. (Image from NASA).

We tend to find a lot of oil in the deltas of the great rivers because the rivers provide nutrients for the microorganisms to survive and layers of sand and clay sediments that trap the oil and natural when they’re produced.

The article also ties the location of oil production to the geography of plate tectonics.

[W]hen Africa and South America slowly pulled apart in the Cretaceous period, forming the narrow beginnings of the South Atlantic. Big rivers poured in nutrients. A biological frenzy on the western shores of the narrow ocean ended up forming the vast oil fields now being discovered and developed off Brazil in deep water. – Broad, 2010

Went fishing

We went fishing yesterday and one of us caught our first fish. I tend to dislike dissection for dissection’s sake, at least with middle schoolers, but I believe that cleaning fish is a practical life exercise everyone should have that accomplishes the same thing. There is also an ethical dimension for anyone who eats meat. I have no opposition to cleaning anything else if we’re willing to eat it.

So we’ll probably be cooking fish this year. There aren’t many places to purchase whole fish in Memphis so we’ll probably end up doing it during our immersions. An article on the ethics of vegetarianism might also make a good basis for a Socratic dialogue.

Texture photography

I’ve always had a predilection for texture photography, despite the fact that I’ve only just now come to realize that there is actually a term for it. The changes in perspective you get from looking at things at different scales continues to fascinate. Texture photography focuses on the small but looking at big things from far away can have a similar effect.

Martian dunes. Image from NASA.

What is life and what is human?

Life has four needs, six characteristics and sixteen patterns, but things only get really interesting with viruses that straddle the line between life and non-life. You can run into similar problems when you ask the question of what makes us human.

Both these questions come up in stories like Pinocchio, and any number of robot books, such as John Sladek’s Roderick. Probably because good books go a lot farther in describing characters rather than appearances, you often start with the question, are they sentient and then backtrack to the question of if they’re alive or not.

Interestingly, many of my students equate the question, are they sentient, with the query, are they human? (A fascinating result given the propensity of humanity to divide into groups based on looks.) Which gives rise to the interesting conundrum, can something/someone be “human” and still not alive? We’ve had some fascinating discussions around that question too.

A great place to encounter these issues is in Mary Shelly’s novel Frankenstein, which also nicely ties-in with the science curriculum since you will probably find it useful to draw out the Frankenstein family tree to keep track of the story. In addition, the historical setting of the book relates to social world issues as the book describes life in the early 19th century, and you realize that the issue of our relationship with technology and science was coming up 200 years ago.

A lighter variant on Frankenstein is Terry Pratchett’s Feet of Clay. It’s a story about golums who are powered only by the words in their head. Unlike Asimov’s three rules of robotics the words are not literal instructions like the programmer’s code, they can be much more metaphorical, like a receipt. Yet, in the end, many of the same questions about life and humanity arise.

Earth Ecology and Terraforming Mars

I’ve been thinking about science fiction, like Mirable and The Chrysalids that tie into the Natural World (science) curriculum. While I’ve not read Kim Stanley Robinson’s Mars triology, Red Mars, Blue Mars and Green Mars, they’ve won a number of awards and I’ve heard good things about them.

I’m looking for books that address global ecology, so stories about terraforming Mars would seem to fit. The Mars triology books are also supposed to be fairly rigorous and consistent about the science, something I look for in good science fiction. There are also some good articles discussing the science that can be used for supporting information, like this one by Margarita Miranova (2008) about the actual feasibility of terraforming Mars.

Feature identified by students from Evergreen Middle School. Image from NASA.

Given Mars’ proximity and the fact that space agencies have orbiting satellites and ground rovers makes the idea of colonizing Mars an intriguing one for the more adventurous adolescents. In fact, the recent news that 7th graders discovered a new feature on Mars’ surface might also inspire some interest. The 7th graders’ project was part of the Mars Student Imaging Program (MSIP), which might also be of interest. MSIP actually allows students to use the camera on board the Mars Odyssey satellite, by identifying locations for detailed images.

Tree of Life Project

Tree of Life web project.

The Tree of Life web project is a growing online collaborative project to:

to contain a page with pictures, text, and other information for every species and for each group of organisms, living or extinct.

Direwolf distribution in the U.S. from Faunmap.

It’s a great starting point for looking at the tree of life because each page has links to a wealth of online resources. One of the links on the Mammalia page, for example, is to Faunmap, an online database that produces maps of where different modern and extinct mammalian species can be found in the United States.

All the pages on the Tree of Life website are linked by the branches of the tree of life. The Class Mammalia links up to its parent Therapsida and down to the its Orders such as Monotremata (one of my favorites) and Eutheria, the placenta mammals.

The site is authored by professional scientists and science educators so has that credibility. Most of the images also allow free, non-commercial use. Thanks to Anna C. for the link.

Censorship!

I spent an hour yesterday censoring Larry Gronick’s, “Cartoon History of the Universe“. I always feel a little dirty after doing it, but the section on the origins of life, particularly the comparison of the relative advantages of asexual and sexual reproduction, does go a little too far with the puns (in my opinion at least).

I do, however, like the book a lot, especially the section on the origin of the universe and history of life on the Earth throughout the Cambrian. I tend to use the bit up till the appearance of humans about 200,000 years ago. Despite being written in 1990 the information is still very accurate. The art is excellent and a pleasure to observe.

Of course, censoring tends only to increase students’ interests in finding out what was blacked out. Fortunately, there’s nothing in the Cartoon History that’s too terrible even if they should decipher it.