Thursday, January 30, 2014

Book review: Moonwalking with Einstein

I'm not sure how many times over the past few years you learn something that makes you question your basic education.

For example, I like to argue, but I never studied rhetoric til recently.

I work in groups, but never learned the keys to making groups work well. Like cross-referencing.

I also try to remember things all the time, but never learned how to remember. I often say my mind is like a steel sieve.

On Joe Fargione's recommendation, I read Joshua Foer's Moonwalking with Einstein.

The book itself is "participatory journalism" by the author as he trains for the US Memory Championship.

It's a quick, fun read.

Of the interesting parts of the book, I felt like I was familiar with "memory palaces"--esssentially transforming items on a list into objects that can be placed in a remembered landscape--but I never tried them out.

That trick (and others) people have used for thousands of years to remember lists.

Essentially, you take an item on the list, picture it in vivid details with multiple clues to help you remember it and then place it on a landscape that you know. Like your home.

Then you just walk through the place and see the items that are there.

One character in the book demonstrated this to the author by giving him 15 random items to memorize.

As I read, I tried the same thing.

Item#1 (pickled garlic): At the base of my driveway, I put a 6-foot jar of pickles and garlic with a vampire on it.

Item #2 (cottage cheese): on the porch, i put a kidde pool of cottage cheese with a small house to remember that it was cottage cheese...

I did this for all 15 items.

Right now, I'll try to remember the list that I tried to commit to memory a week ago.

A week later, I can walk from my old driveway to the backyard and see:

pickled garlic
cottage cheese
peat-smoked salmon
6 bottles of white wine
3 pairs of socks
3 hula hoops
scuba gear
dry ice machine
email sophia
Paul Newman's Somebody up there likes me
elk sausage
directors chair and megaphone

Darn. That's only 14.

I just looked back at the list and forgot that at the bottom of the stairs was a skin-toned cat suit. That was supposed to come after email sophia. Must have stepped over it.

Also it was a snorkel, not scuba gear, and a harness and ropes, not just a harness.

Not bad, though.

Apparently, we are much better at remembering places than odd collections of items/tasks/feelings.

Placing items in a remembered landscape is one way to aid recollection.

There are other tricks, too, that I haven't tried. Like for remembering long strings of digits.

Thursday, January 23, 2014

Evolution of freezing tolerance

The ancestral plant was woody, evergreen, had large vessels, and lived in warm habitats.

Over time, trees radiated into cold environments by becoming herbaceous, deciduous, or having small vessels that are less likely to cavitate with freezing.

To understand the order of all this, the authors co-analyzed phylogenetic patterns of climate occupancy, woodiness, and vessel size for a large number of species.

The time-scaled molecular phylogeny is a key innovation with this work, but joining the databases on traits hasn't been done either.

The main finding is that the main adaptations to freezing evolved before moving into cold environments: "freezing environments were largely filled by lineages that had already become herbs
or...already had small conduits". 

Deciduousness is the exception: "most deciduous woody lineages had an evolutionary shift to seasonally shedding their leaves only after exposure to freezing". Think live oaks to deciduous oaks.

Summarized another way "First, the pathway to herbaceousness or small conduits in freezing environments largely involved acquisition of the trait first (followed by adaptation to a new climate), whereas the pathway to deciduousness in freezing environments was largely via a shift in climate occupancy first (followed by evolution of the trait)."

The trailing question is what drove pre-adaptations to freezing. Was it drought? Nutrient limitation?

An independent dataset on these traits should help answer these questions.

In all, nice paper by Zanne et al. in Nature.

[Note on sample size for myself, if I read right, there were data on growth habit for 39k species, climate and phylogenetic for 32k species, leaf phenology (evergreen vs. deciduous) for 2630 species and xylem vessel size for 860 species.]

Research topics for Nature

In Oxford, I had the great privilege of spending the semester with Yadvinder Mahli's tropical forest research group. I learned a ton about the biome. It was a real treat.

One thing I learned is that there seems to be a lot of great research being published in Nature on tropical forests. It seemed like every week there was a new paper in Nature.

Each one seemed deserved, but I wasn't sure if there really was more good research coming out of tropical forests than say temperate forests or grasslands.

So, I did a search in Nature for research articles published 2012-2014. The search was by keyword.

Results are above.

It seems to be true. On average, about once a week, there is a paper that is associated with tropical forests. Temperate forests? 1 every 2 weeks. Boreal, once a month.

Grasslands? Less than once a month.

The numbers up there really do seem to match funding levels. I'm surprised tropical forests : grasslands is just 5:1 to be honest.

I double-checked to make sure I spelled chaparral right. I did.