Saturday, May 31, 2008

Artificial selection produces an impressive array of wild mustard varieties.

- "Artificial selection is the selective breeding of domesticated plants and animals."
- "For example, broccoli, cauliflower, cabbages, Brussels sprouts and kale are all varieties of a single species of wild mustard."

Wikipedia entry on Brassica oleracea, Brassica.

Textbook cited: Biology: Concepts & Connections. 5ed. Campbell, Reece, Taylor & Simon.

Vegetarianism is about human rights; an argument from biology.

This week (of June 2) my biology students will be reading a chapter on communities and ecosystems.

Here are a few selected facts from their readings, for your consideration:

- "Each day, planet Earth receives about 10^19 kcal of solar energy." The textbook compares this amount of energy to the energy of 100 million atomic bombs. For your reference, one kcal is equal to 4184 joules.
- "Most of this energy is absorbed, scattered, or reflected by the atmosphere or by Earth's surface."
- " . . . only 1% is converted to chemical energy by photosynthesis."
- " . . . on a global scale this is enough to produce about 170 billion tons of organic material per year"
- "When energy flows as organic matter . . . much of it is lost at each link in (the) food chain."
- "The efficiencies of energy transfer (from one level of the food chain to the next) usually range from 5 to 20%. In other words, 80 to 95% of the energy . . . never transfers from (one level) to the next."
- "An important implication of this stepwise decline of energy in a trophic tructure is that the amount of energy available to top-level consumers (carnivores) is small compared with that available to lower-level consumers (herbivores)."
- This explains why "food chains are limited to three to five levels; there is simply not enough energy . . . to support another (level in the food chain)."

For example:
1,000,000 kcal of sunlight > 10,000 kcal of plant vegetation > 1,000 kcal of primary consumers > 100 kcal of secondary consumers > 10 kcal of tertiary consumers

- "Eating meat of any kind is an expensive luxury, both economically and environmentally."
- "Based on the rough estimate that 10% of the energy available in a trophic level (level of the food chain) is available at the next higher level up ... the human population has about ten times more energy available to it when people eat corn than when they process the same amount of energy of corn through another tropic level and eat corn-fed beef."
- "It is likely that as the human population expands, meat consumption will become even more of a luxury than it is today."
- Demand for meat drives up the prices of grains, fruits and vegetables because "potential supply of plants for direct consumption as food for humans is diminished by the use of agricultural land to grow feed for cattle, chickens and other meat sources."

And the pièce de résistance: Boss Hog: America's top pork producer churns out a sea of waste that has destroyed rivers, killed millions of fish and generated one of the largest fines in EPA history.

What do you think of this post format? It makes it much easier for me to share interesting facts & ideas that I'm thinking about on a short time budget, but it's no good if you guys find it unpleasant to read. If it's a hit, then let me know if there are any topics in biology you'd like me to cover.

Textbook cited: Biology: Concepts & Connections. 5ed. Campbell, Reece, Taylor & Simon.

Wednesday, May 21, 2008


From One Laptop per Child, this is the design for the XOXO, planned for a 2010 release. The current iteration looks very much like a toy, but this thing is just sleek. Oh, to be a child in 2010!

They showed off the current design at the Design and the Elastic Mind exhibit, and before that I wasn't terribly interested in the project, but getting close certainly piqued my interest. They're creating a new interface designed to be natural for children to use, which indeed means natural to anyone not entrenched in the current (am I really about to say this?) desktop/window paradigm. Which plays a part in a larger move towards natural interfaces that I'm very much thrilled to be in the midst of. What will a generation of children raised on this mean for computing? For communication? I can't wait to see!

Via TED.

Tuesday, May 20, 2008

‘At least 12% of US biology teachers are creationist’

So says research reported on in The Great Beyond. What in the world is wrong with us?

Saturday, May 17, 2008

Bioluminescent Tides

"Bioluminescent dinoflagellates (Lingulodinium polyedrum) lighting abreaking wave at midnight. The blue light is a result of a luciferase enzyme (like firefly luciferase, but the enzyme in L. polyedrum shares no similarity with that of the firefly enzyme). Under the right conditions, the dinoflagellates become so numerous that the water takes on a muddy reddish color (hence the name "Red Tide"). The bioluminescence is only visible at night. The photo was taken 6/26/2005with a Canon Rebel XT - 6s, f5.6, ISO 1600, 85mm (135mm equiv)."(Images and text from Flickr's msauder. Click to view the rest of his photostream.)

Apparently, "the last sinking of a German U-boat in WWI occurred in 1918, when dinoflagellate bioluminescence revealed its location (Tarasov 1956)."
(Live Marine and Freshwater Phytoplankton)

Fractal Furniture


Wednesday, May 14, 2008

Shrimp Eyes

Apparently the most enviable species on the planet is not the ant eater. Far from it, in fact. It's the mantis shrimp.

Look at that guy. He can do so many things that you can't. Specifically, he's got 11 or 12 primary colors ranging from infrared to ultraviolet and can apparently, as researchers have recently discovered, also see six forms of polarization. You see something like one form. An interesting fact from the linked press release is that "the physics we used to understand what was going on [in the mantis shrimp's eye] is the same physics that we use in quantum computing for optimal storage of information."

Via The Great Beyond.

Bird Brain!

For a couple weeks I've had a tab open in my browser with the sole intent of writing a quick post about it. I came across an old Neurophilosophy article talking about avian intelligence, crows in particular. It cast birds in a completely new light for me, which is always a welcome event. They went from being creatures that lived in a completely foreign way to being more familiar thinking beings, problem solvers. There are videos included in that article that demonstrate the ability of these crows to learn and adapt to our environment in what I think are remarkable ways. They craft tools with whatever they have lying around; they use traffic to crack nuts!

A perfect followup to that article is this video of Joshua Klein talking at this year's TED conference in which he discusses the intelligence of crows and explores the possibility of humans working symbiotically with them. Definitely worth ten minutes of your time.

Thursday, May 1, 2008

Blue Brain

Somewhere in Switzerland, a team of researchers has spent a great deal of time learning exactly how a neocortical column works and they've built a supercomputer to simulate it perfectly.

It didn't take long before the model reacted. After only a few electrical jolts, the artificial neural circuit began to act just like a real neural circuit. Clusters of connected neurons began to fire in close synchrony: the cells were wiring themselves together. Different cell types obeyed their genetic instructions. The scientists could see the cellular looms flash and then fade as the cells wove themselves into meaningful patterns. Dendrites reached out to each other, like branches looking for light. "This all happened on its own," Markram says. "It was entirely spontaneous." For the Blue Brain team, it was a thrilling breakthrough. After years of hard work, they were finally able to watch their make-believe brain develop, synapse by synapse. The microchips were turning themselves into a mind. #

Henry Markram, the director of the Blue Brain project, takes issue with the strictly-empirical nature of neuroscience and favors a more model-based approach akin to physics. It's in that spirit that he and his team have come up with Blue Brain, where its "virtual neurons are more real than reality."

After scaling up the current iteration of Blue Brain, he plans to give his virtual brain a body in the form of a robotic rat (all his work is being modeled around the likeness of a two-week old rat) and watch it grow into a real mind, learning through its body just as any 'real' animal.

This is one of the most exciting articles I've read in ages, and I urge you to take the time to read it yourself. I always sort of wondered how we'd get from our current state of technology to Kurzweil's Singularity, and this has the distinct feel of being the direct course to that end.