Next year we’ll be going into the differences between plant and animal cells, as well as into the differences between plants and animals. There are a number of fundamental differences, starting with the fact that plants can photosynthesize to convert sunlight directly into energy and animals can’t. Except for the sea slug. Sea slugs have found a way to pirate chloroplasts from green algae (found via Immersion Blog).
Chloroplasts are the green cellular bodies (organelles) that perform photosynthesis. The species Elysia chlorotica eats the algae when they are young and instead of digesting them entirely, keep the chloroplasts in their gut.
Young E. chlorotica fed with algae for two weeks, could survive for the rest of their year-long lives without eating – Brahic, 2008
What’s even more intriguing is that there is evidence that the sea slugs have incorporated parts of the algae into their own DNA so they can maintain the right conditions for the chloroplasts to survive in the new host (Rumpho et al., 2008). The Sea Slug Form has a nice page on other solar-powered slugs.
Mathematics is the language of science. Scientists refine and refine their observations of the complexity of the natural world and try to boil these complex observations down to simple relationships, relationships that are expressed in mathematics. This, I think, is part of the human condition. Our brains are designed to extract simple relationships, heuristics, rules of thumb, from the observations of our senses. It is why Einstein’s equation, E=mc2, has captivated our imagination for so long, why physicists struggle to find the unified theory, and why fractals are so fascinating.
Cristóbal Vila’s short video (found via The Daily Dish) captures some of the magic of the relationship between mathematics and the world.
Adolescents like to tick you off. Push all of your buttons to see what happens. And you want to ask, “Who are you really?” and, “Do your really not care?” We probably did the same when we were that age, but do you also remember how idealistic we were? The video below, from Penguin Publishing (found via The Dish) captures a bit of that duality of the adolescent mind. The use of white space and of just simply words also ties it quite nicely into our ongoing discussion of poetry in a “spark the imagination” kind of way.
If you don’t have a generator building kit, but do have a few magnets, some wire and a long nail, you can build your own generator using the instructions on William Beaty’s website, ‘Ultra-simple Electric Generator‘. The video gives excellent, detailed instructions, but there are also written instructions with a supplies list.
UPDATE: A small group of my students tried this and, despite the complaints, I thought it was a useful exercise. I’m looking forward to their presentation tomorrow.
Looking through the Greater Good Science Center‘s blog post on how to raise kind children, I was struck, as I usually am, by the somewhat counter-intuitive finding that we should not reward good behavior (helping in this instance).
Very young children who receive material rewards for helping others become less likely to help in the future compared with toddlers who only receive verbal praise or receive no reward at all. This research suggests that even the youngest children are intrinsically motivated to be kind, and that extrinsic rewards can undermine this tendency. – Carter (2010)
While I have not yet looked to see if there is any direct research on this topic with regards to adolescence, this is part of the Montessori philosophy. Lillard (2007; Ch. 5) has an entire chapter on Extrinsic Rewards and Motivation that gets to the same point. She cites the research that gets to the specific point that extrinsic rewards, rewards that come from the outside such as praise, tend to demotivate once the rewards are removed.
Engaging in a well-liked activity with the expectations of a reward led to reduced creativity during that activity and to decreased voluntary participation in that activity later. (Lepper et. al., 1973) in Lillard (2007; Ch. 5)
Rewards have negative effects when they are clearly stated, expected, and tangible; read this book and you’ll get $5; or do this work and you will get better grades. However, rewards can work if you’re dealing with subjects that students find uninteresting and there is a very clearly specified set of steps that they can learn by rote.
“[R]ewards are often effective at the moment of their offering, so if there are no long-term goals, rewards help without causing harm down the road.” Lillard (2007; p. 157)
Rewards can help with basic learning, like memorizing facts, but intrinsic motivation is essential for tasks that require higher-level more creative thinking.
I try to praise or give tangible rewards very rarely, though it is often hard. Students look for praise sometimes (and sometimes for the oddest things), so when I do complement I try to use what Carter calls growth-mindset praise and say something like, “See, practice really pays off.” Praise the effort, not some intrinsic value the students have.
This is an excellent program (and website) that really delves into a lot that is counter-intuitive about adolescents. It is strongly recommended for both teachers and students, because it goes into the fundamental question of why your teens seem like aliens. Indeed, it describes the type of research upon which the Montessori Middle School program is based.
To accurately observe nature sometimes takes time. Land-labs are intended to get students out into nature for a week at a time throughout the entire year so that they can see the change in the seasons. But sometimes you need to winnow things down, speed things up, to observe the slow changes that you just miss. Time-lapse photography is one great way to do this.
I showed my class two YouTube videos from Amnesty International that promote their letter writing campaigns. The videos use spare black and white imagery and signatures, written in the air, are used by victims of human rights abuses to escape their persecutors. The video above did provoke a few giggles, because, I suspect, the character animation has a bit of humor to it despite the seriousness of the issues being portrayed. The video below is more powerful. It more frankly addresses the fact that human rights violations are taking place and some of its subjects are children (e.g. child soldiers).
Not all of the students understood at first that the signatures were meant to be their own, and the purpose of the video was to encourage the viewer to write, but they cleared that up after a short discussion. I hope the videos have some long term effect, because pretty promptly after the brief discussion they tried to convince me that I should show the YouTube video of the “Evolution of Dance“.