Sunday, September 30, 2012

The Citron of the Tabernacles

Varieties of Citron (citrus medica)
Oranges, grapefruits and lemons, tangerines, limes and maybe even a pomelo are types of citrus fruits we eat, or juice, all the time. But how many of you are familiar with the citron?

The citron has been around for thousands of years, and when crossed with other species, gave rise to the different citrus varieties we know and love today. But aside from its fragrance, the citron does not have many redeeming qualities, especially as it is almost devoid of juice and has a thick rind. While this can be candied to make succade, the citron's main uses have been religious.

The small etrog I bought for this year's Sukkot holiday
In the Book of Leviticus it is written: "And you shall take on the 1st day (of the Feast of Tabernacles, Sukkot) the fruit of beautiful trees...". The citron, known in Hebrew as the etrog, has always been assumed to be this fruit, as indeed the literal translation of the Hebrew word for "citrus" is eitz hadar, which literally translates as "beautiful tree". Because god commands us to use the etrog during the Feast of Tabernacles, the trade in citron, and especially beautiful unblemished fruit, can get competitive and expensive. The search for the perfect etrog was even the subject for an excellent movie, Ushpizin, which I highly recommend.

Happy Sukkot!

Sunday, September 16, 2012

An Apple for the New Year

"Why do we need so many kinds of apples? Because there are so many folks. A person has a right to gratify his legitimate taste. If he wants twenty or forty kinds of apples for his personal use…he should be accorded the privilege. There is merit in variety itself. It provides more contact with life, and leads away from uniformity and monotony." -- Liberty Hyde Baily

In the spirit of the Jewish New Year, some apple facts:
  • Origins: Khazakistan (Thanks Borat!) and surrounnding regions in Central Asia
  • # of genes (in Golden delicious): 57,000 (more than any other plant so far)
  • First eaten by: Eve
  • # of cultivars: 7,500
  • amount grown in 2010: 60 million tonnes
  • Largest grower: China
  • Largest grower in US: Washington

And lastly, for those going to a Rosh Hashana meal, here is the proper way to dip an apple in honey:

Monday, September 10, 2012

Do plants feel pain?

"Does it hurt my vegetables when I eat them?"
"Is it ok that I prune my bushes?"

These questions, and many like them, pop up whenever I've given a talk or been interviewd about the WHAT A PLANT KNOWS. Truth is, I didn't fully anticipate this take on plant senses, but it seems that the book has, so to say, struck a nerve, with many readers who are concerned for the welfare of their plants.

But indeed, the question of plant sentience is perhaps only an extension of our interest in understanding consciousness in general, and by extension, suffering.

Neuroscientist Daniel Bor recently wrote a great piece in Slate entitled When Do We Become Truly Conscious? that can help us come to terms not only with animal suffering, but plant (lack of) suffering as well.

In analyzing when a a human becomes conscious, Bor writes:
"The evidence is clear that a fetus can respond to sights, sounds, and smells, and it can even react to these by producing facial expressions. The evidence is equally clear, however, that these responses are generated by the most primitive parts of the brain, which are unconnected to consciousness, and therefore these actions don’t in any way imply that the fetus is aware."
If we replace "fetus" with "plant" and make a few edits for scientific clarity, we get:

The evidence is clear that a plant can respond to sights, sounds, and smells, and it can even react to these by changing development [many example of this in WHAT A PLANT KNOWS!]. The evidence is equally clear, however, that these responses are generated in the abscence if a brain, and thus is unconnected to consciousness, and therefore these actions don’t in any way imply that the plant is aware.

Obviously in philosophical debates such as these, semantics play a key role. Bor and I don't use the word aware  in the same way.In WHAT A PLANT KNOWS I posit the thesis that plants are indeed aware of their environment. But they are not conscious, at least not in the way that Bor uses awareness and consciousness:
"In adult humans, for normal consciousness to occur, it is now generally agreed that two sets of regions need to be intact, functional, and able to communicate effectively with one another: the thalamus, a kind of relay station in the middle of the brain that connects many regions with many others; and the prefrontal parietal network, our most high-level, general purpose section of cortex. If either the thalamus or prefrontal parietal network is substantially damaged, the patient is likely to enter into a vegetative state, with virtually no sign of consciousness."
Psychologists, physicians and neurobiologists alike have come to a consensus that suffering, which is subjective, is located in the prefrontal cortex, while pain centers are located deep within the human brain that radiate out from the brainstem. The International Association for the Study of Pain meshes pain and suffering and defines pain as “an unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage.” So if suffering from pain necessitates highly complex neural structures and connections of the frontal cortex, it follows that plants obviously don’t suffer – they have no brain.

So munch away on your celery stalks; take pride in your ability to chop tomatoes; and prune your oak so that it doesn't obstruct a path. Your plants may "know" what's happening, but frankly my dear, they don't give a damn.

Thursday, September 6, 2012

Buckshorn plantain: the strange green stuff on the top of a salad

Steamed hake with buckshorn plantain, reedmace and
sorrel butter. Taken from here

I never heard of buckshorn (pronounced bucks-horn) plantain , until Jeremy Cherfas posted about it on Facebook. But I've unknowingly eaten it as the unidentified green stuff garnishing sophisticated salads. While native to the Old World, this salad green has been grown in the United States for several hundred years. Today, buckshorn plantain (Plantago coronopus) is often known as “minutina” or “herba stella”. The plant’s common name is derived from the shape of its leaves: narrow, spiky and antlerlike Buckshorn plantain can be harvested as a wild salad, or bought in higher-end vegetable markets. Read more about buckshorn plantain here.

Monday, September 3, 2012

Guest blog: Jonathan Gressel - Exposing anti-GMO propaganda veiled as science

Danny: The following is a public letter written by my colleague Prof. Jonathan Gressel at the Weizmann Institute, in response to talk from an ecologist decrying the use of transgenics in agriculture. I edited the letter, shortening it for use here. I should point out that Dr. X. is a zoologist at a well known university. As the gossip is less important than the content, I decided to leave her anonymous as "X" here.   I should also point out that no response was received from "X" to this letter.

Dear Dr X,

I was rather disturbed by some of the disinformatory remarks that you made yesterday at the symposium [Genetic Engineering in Agriculture - Dream or Necessity?], especially in relationship to transgene flow. You categorically stated that there have been no studies on this (or any) area of ecology/population genetics of transgenics in Israel. My students, colleagues, and I have published over 40 papers on the subject since 1999 demonstrating that you have hardly done your homework  - or in the parlance of journal editors - this is an ethical defect known as "citation amnesia".

You also made dire warnings about gene flow (via pollen or seed) to the wild, and claimed in a slide that there was evidence for this. A careful reading of the data behind the slide would have led you to a different conclusion. Competent ecologists distinguish between agro-ecosystems, ruderal (human-disturbed) ecosystems, and wild ecosystems. There is no published evidence that there has been gene flow to any wild ecosystem, and as you should know, there are exceedingly few instances of crops growing anywhere near wild interbreeding relatives. The real issue is gene flow to weeds in agroecosystems, which is controllable, and regulators should assure that there are transgenic failsafe mechanisms installed to prevent such problems.

You implied that organic agriculture is incompatible with transgenics - I strongly suggest that you read the book co-authored by a professor of organic agriculture, and head of the program at UC-Davis, who rather considers otherwise [Tomorrow’s Table: organic Farming, Genetics and the Future of Food. Pamela C. Ronald and Raoul W. Adamchak].

You also implied that there was a consensus among ecologists that transgenics were highly dangerous (I believe you put it as "all the ecologists I talked with"). There are highly competent ecologists (including the only ecologist among the founders of Greenpeace) who argue strongly for transgenics as being an exceedingly invaluable tool for protecting the environment [Confessions of a Greenpeace Dropout: The Making of a Sensible Environmentalist].

Indeed many meta-analyses performed by ecologists have shown the distinct environmental benefits of transgenics over current conventional agricultural practices (and even moreso over organic agriculture).

Thus, it is hard to conclude that you presented an impartial review of the ecological implications of transgenics that would have been expected of an academic ecologist at an important university.

This is very unfortunate.


Prof. Jonathan Gressel
Plant Sciences
Weizmann Institute of Science
Rehovot, Israel 76100