The Fruit Hunters [Review]

I found myself in an Annapolis pub, discussing dental anthropology over oysters on a cool, wet Maryland evening. Raw oysters are not my favorite bivalve, but I enjoyed hearing Jim describe his Madagascarian classroom, where he was studying the diet of lemurs for his Ph.D.

I asked him what type of foods human teeth are adapted for. "Well..," he hesitated, explaining the controversy over whether teeth are adapted to chew an animal's main food, or its food of last resort.

"Okay, but what are human teeth adapted for?"

"Fruit."

It was always a nice reward after a 110 degree bike commute to stop for figs in the shade of an abandoned field. My grad school roommates and I would often meet in the kitchen after work to discuss the tree's progress and plot to strip armloads of the soft, aromatic fruits before the birds caught on. I remember Mel spilling grocery bags full of homegrown pomegranates across our seminar lunch table and myself crushing walnuts against tree trunks on the department farm. Pausing in dusty redwood clearings to sample blackberries among the hoppers, wasps and rattlesnakes. Or pulling down rain-sopping mulberries on a dark summer night, waiting to help Amelia move.

There's something peaceful and familiar about foraging for fruit. I always felt that my research time spent pawing through low evergreen canopies on Sonoma ridges, searching for bright orange patches was apt for an animal adapted to find colorful fruit in a sea of leaves.

These memories came back to me as I sank into Adam Leith Gollner's The Fruit Hunters. I was immediately hooked by his playful use of language and allusions, and by his somewhat stream of consciousness rhythm (which struck me as oddly reminiscent of my own attempted style). He quickly convinced me that the world is full of many thousands more species and varieties of fruit than I could ever imagine, or that a dedicated fruit hunter could ever track down. He wound stories of explorers and ancient mythology, illuminating a world where mundane, everyday fruit were hiding centuries of stories.

I enjoyed as he rattled off random facts about random fruit:
Grenades were inspired by exploding dehiscent pomegranates. (Grenade is French for pomegranate). Explosive dehiscence also occurs in wisteria and sesame fruits (hence, "Open sesame!")
Some fruits mimic centipedes, worms, spiders and horned beetles so bird and insect predators will disperse them.
Giant fruits that have lost their ancient animal disperser (e.g. avocados, prickly pears, osage oranges and papayas) are known as "anachronisms."
Fig wasps (which symbiotically pollinate fig flowers and raise their young in the fruit) are dissolved by the chemical ficin after they die within the fruit.
The miracle fruit contains sugar-mimicking chemicals that stick to the tongue, making all sour foods taste sweet, and was outlawed by the FDA (i.e. sugar industry) in the 1960s.
Maraschino cherries are just the worst quality cherries, bleached, dyed and flavored artificially, but were adapted from a sour cherry liqueur, popularly used in Eastern Europe to preserve sour Marasca cherries.

Unfortunately, he began to lose me after the second chapter. The rest of the book increasingly follows the adventures of wealthy eccentrics whose tales don't live up to the hype of their mystical fanaticism for fruits.

He lost me altogether as he began to spout random "facts" on agricultural science that were flat wrong:

It is NOT a secret which foods have been genetically engineered.
No commercial tomato ever had flounder antifreeze genes in it.*
He refers to black sigatoka disease as being caused by a virus.
GMOs ARE tested for safety - by the USDA, FDA and EPA.
He also reported numerous absurd health claims about different fruits (possibly tongue in cheek)

He also makes sweeping generalizations about the dangers of pesticides. Every single molecule that exists in the world is toxic at some concentration (yes, even water). It's beyond irresponsible to conflate the ability of pesticides to injure experimental animals with the danger that trace residues pose.

His funniest screw up was his shock at seeing the fine print on a California IHOP that warns of the presence of "chemicals known to cause cancer or birth defects or other reproductive harm." He blamed it on industrial, processed food, but a better journalist would have learned that California passed some law requiring these signs everywhere (e.g. every apartment I'd lived in).

All in all, it's worth reading if you have nothing better to do. I was fascinated by the beginning, but any given fact (including the ones I listed) are dubious.


* Here's the history behind that dumb tomato with flounder genes rumor:
For years now, it's been a routine academic approach in plant biology to express foreign genes in experimental plants to see what happens. In this study, they expressed animal antifreeze proteins in a plant. They make the (far-fetched) suggestion that expressing native plant antifreeze proteins in crops could protect them from freezing damage. These plants are not grown commercially and were probably destroyed as soon as the experiment ended.
Hightower R, Baden C, Penzes E, Lund P, Dunsmuir P. 1991. Expression
of antifreeze proteins in transgenic plants. Plant Molecular Biology
17: 1013±1021.

The Great Ag (healthcare) Experiment

The New Yorker has a pretty incredible article on the history of American agriculture. It describes how the U.S. was transformed from a land of unskilled subsistence farmers to an agricultural (and political) superpower - largely thanks to a network of government scientists and extension agents.

In 1900, poor agricultural practices exhausted and destroyed most farm plots in fewer than 5 years and the typical family spent more than 40% of their income on food. Agriculture was built on an unproductive combination of tradition, superstition and hard labor. Most farmers were incredibly recalcitrant to new ideas, which were often derided as "book farming." As the food cost crises intensified, the U.S. government stepped in - not with an Agricultural Central Planning Agency, but with a distributed network of experimental and demonstration farms in small towns across the continent. USDA scientists and extension agents at these stations worked personally with local farmers to develop and communicate best practices for their crops in their region.

"What seemed like a hodgepodge eventually cohered into a whole. The government never took over agriculture, but the government didn’t leave it alone, either. It shaped a feedback loop of experiment and learning and encouragement for farmers across the country. The results were beyond what anyone could have imagined. Productivity went way up, outpacing that of other Western countries. Prices fell by half. By 1930, food absorbed just twenty-four per cent of family spending and twenty per cent of the workforce. Today, food accounts for just eight per cent of household income and two per cent of the labor force. It is produced on no more land than was devoted to it a century ago, and with far greater variety and abundance than ever before in history."

According to this article, the current Senate health care bill is following in these footsteps to tackle our current crisis of out of control costs. Despite all the hype about whether or not this bill will have a public option or cover abortion, the core of this bill is apparently dedicated to giving organizations and communities across the country the freedom to experiment with how they will administer and pay for health care. It would harnesses both the creativity and ingenuity of individuals to develop new systems and the government's ability to organize and communicate the results.

This American Life came to the same conclusion after a fascinating tale of the history of U.S. health insurance. I sure hope it works!

* Although both pictures look "old," the first (1921) shows the adoption of very efficient (though capital-intensive) mechanization over human and animal labor (1886).

NO FRACK (ing)

Cryptic black signs with an X through the word "Frak" have appeared all over town. This failure of graphic design is an abomination.

"Ok, you have my attention... so howabout adding a website or something so I can actually find out what you're trying to advertise!?!?"

Luckily, one of our local papers had a story describing the proposed extraction (fracking) of natural gas from the Marcellus Shale (which I had heard about). NPR's On Point got me up to speed.

The U.S. has massive untapped reservoirs of natural gas, which burns much cleaner than coal (which I already knew thanks to SimCity). "Hydrofracking" fractures natural gas containing formations with high pressure water, making the formation more permeable and allowing the more rapid collection of natural gas (or other fuels). According to the guests, this process has been used extensively in many parts of the country (e.g. Texas) with little to no environmental impacts. Apparently, one of the major suburbs of Houston is completely undercut by hydrofracking equipment and pumps are located within 100 feet of houses!

Contrarily, operations in other locations (especially Pennsylvania), have been blamed for groundwater contamination with all sorts of toxic industrial chemicals, in addition to more fanciful claims, such as generating earthquakes. One guest seemed to say that, while operations in places like Texas have been shown to be pretty much 100% safe, it is not unlikely that the unique geological characteristics of the Marcellus Shale may cause additional hazards.

So I guess I would be against it? (at least until the safety has been investigated further?)

I do think it's important to balance these pros and cons against greater concerns though. One caller reminded us that potential environmental contamination may be the alternative to our ongoing military involvement in the Middle East. I don't know what the right decision is, but I'd hate to see the wrong decision be made just for NIMBY.

Native Gardening isn't always Sustainable

A nice post by The Garden Professors - reminding us that native plants aren't always the best choice for gardeners looking to maximize biodiversity and minimize resource usage.

h/t: Greensparrow Gardens

"We Are What Our Ancestors Ate"

Evolutionary biologists discussed the ideal human diet at a recent meeting.

Our ancestors enjoyed a range of diets - from generally omnivorous australopithecines, through Homo species that increasingly specialized in large game, to the incredible variety of diets that creative H. sapiens cultures have come up.

These regional diets have left imprints on their descendants. This article discusses how people of warm lowlands (e.g. the Pima of the American Southwest) may have developed slow metabolisms to withstand famine and heat while people from cold climates (e.g. the Saami of Norway or Quechua of Peru) may have developed fast metabolisms to convert fat to energy efficiently. All peoples suffer when exposed to the modern Western diet, but the extent to which they develop specific diseases (e.g. obesity, diabetes, high cholesterol or heart disease) depends on their biological history.

There's no shortage of debate over exactly what characterized the Paleolithic diet for humans in different times and places, but I guess there's consensus in the paraphrase:

"More meat, Fewer carbs, No milk."

I especially like how this article brings the academic discussion back down to Earth:

"Others noted that even if one paleodiet proves particularly healthy, it would be hard for people in different cultures to comply with it. "Food is identity," says Ungar. "You can't tell an Eastern European Jew to eat pork" or an Italian to skip pasta. The bottom line, says Leonard, is that although some diets are better than others, "there isn't a perfect diet that is the same for everyone. The nature of our success is to find and make a meal in virtually any environment. But our different responses are structured by the basic biology we bring to the table.""

h/t: John Hawks Weblog

Farming Brooklyn's Rooftops

I just discovered the blogs of Brooklyn Grange and Rooftop Farms.

I'll be keeping an eye on them!




h/t: the irresistible fleet of bicycles

Meat Consumption and Greenhouse Gasses

A study from UC Davis asserts that animal ag is not an important source of greenhouse gasses and decreasing meat consumption, therefore, is not an effective way to fight climate change.

"Mitloehner said leading authorities agree that, in the U.S., raising cattle and pigs for food accounts for about 3 percent of all greenhouse gas emissions, while transportation creates an estimated 26 percent."

h/t: Advocates for Agriculture

Virus Melts Caterpillar!

I recently saw a presentation on the molecular biology of baculoviruses and was blown away by the missed opportunity to discuss their ecology.
If the speaker had introduced this fascinating group of viruses properly, the audience would have been much more interested in what he had to say.

The lifecycle of a typical baculovirus begins when a caterpillar ingests virion particles while feeding on a leaf. The virus exists in two different forms - a tough protective structure that can survive the elements and an infective structure that travels quickly through the insect's body.

The former version of the virus can withstand harsh environmental conditions -heat, solar radiation and rain - but it breaks down in the incredibly alkaline environment of an insect's midgut (pH as high as 10 or 12!). This alkalinity (on par with ammonia!) dissolves the virion's protective matrix and allows the virus' nucleic acids to climb into the insect's gut cells. The virus then transforms to its latter form and spreads throughout the body by budding off each infected cell in little bubbles of cell membrane.

In Manduca sexta (pic.), this virus also seems to induce the caterpillar to wander up high into branches before it dies. This was noticed in Germany in the 1900s, where it was called "wipfelkrankeit," or, tree-top disease. At this point the virus enters its lytic phase, bursting cells and inducing the caterpillar's own cells to produce chitnases that digest the exoskeleton. The sick caterpillar literally melts, leaving only a black, virus-filled stain on the leaf. The slurrified caterpillar drips and falls down through the branches, contaminating every leaf it touches. Our very hungry caterpillar got infected by eating the liquefied corpse of another.

Because these virion particles are water soluble, they can likely be found on every land mass and in every body of water on Earth - and are certainly present on most of the fruits and veggies you eat! Luckily, they're harmless to us. In fact, they're so incredibly species-specific that they haven't been very useful as biopesticides since growers usually need to control more than one bug at a time. There are just a few commercial preparations, including one that the USFS uses to control gypsy moths. Baculovirus biopesticides (like many forms of biocontrol) are kinda tricky to use, and therefore expensive, but a few labs are working on discovering/engineering more effective viruses strains.

Urban Hunting

Yet another interesting foodie article from the NY Times: The Urban Deerslayer. They describe the recent appearance of urban hunting clubs that cater to novices who may never have so much as held a gun or carved a turkey.

I'm all for anything that gets people more involved in nature. People who interact intensively with nature understand it much better and make more meaningful efforts to conserve it. Some people like to watch birds, some like to climb mountains and some like to hunt - these are all valuable nature educations, plus the hunters (like gardeners!) learn something about where their food comes from.

Besides, the Midatlantic-Northeast deer herd is absolutely out of control. It's very satisfying how quickly our abandoned ag land has exploded with secondary forests in the past few generations but, lacking predators, the deer population has also exploded. I'd love to spend time in local woodlands that haven't had every sign of greenery within 6 feet of the ground scoured clean.

h/t: The World's Fair

Fake Flowers

I was just at the store and saw poinsettias covered in glitter.

Gross.

Vernalization FAIL

They keep promising snow but it hasn't happened yet...
It hasn't really been warm the past week, but it's definitely less cold than I'd expect. Less cold than the daylilies expected too, apparently. A few plants species have been pushing out leaves recently, but the daylilies have 1-2 foot flower stalks topped with little green buds. I joked to my officemate that if they make it another week we may have fresh cut flowers in our office. Or I could just deep fry them.

Vernalization is the process by which plants time dormancy during a cold winter. They simply go dormant when it gets cold and then start growing during the first warm period following a certain period of cold temperatures. This usually works, but our crazy, indecisive Mid-Atlantic winters don't make it easy. Back in Delaware, we'd commonly get snow and 70 degree temperatures within two weeks.

The ornamental flower industry commonly uses controlled cold periods to trick temperate flowers (like bulbs) into blooming on time for our holidays. I currently have a bunch of pawpaw seeds in my fridge for the same reason.

Plumalmondterine

One of the universal benefits of working in an ag lab is the leftovers. Especially in California. We used to get everything from pesticide trial "control" strawberries to extra non-inoculated avocados, to thank you gifts from growers of almonds (not to mention wine!).

One of the coolest treats was an accident.

My grad school PI ran disease screens for a peach breeder who, I think, was trying to introgress some pathogen resistance gene from almond to peach. Peaches and almonds (along with plums, cherries and apricots) are in the genus Prunus. It seems odd at first until you see what an almond fruit actually looks like (pic.) and realize that that the almond "nut" is homologous to the seed inside a peach pit. Almond fruits are even fuzzy! My Jordanian friend once told me that the fruits themselves (when immature and green) are a popular snack in the Middle East.

During the summer we received weekly deliveries of hybrid peach x almond fruits to inoculate - the extras we ate. One week stands out in my memory. This batch looked like nectarines but had deep red-purple flesh with the taste and rubbery texture of a plum. And in the center of each fruit there was an almond where the pit should have been! It was like eating a fruit that came with a candy dessert at the end.

We carefully nibbled at pieces of the "almond," as the wild relative of this crop, the bitter almond, releases cyanide when chewed. It tasted like a normal almond but we threw it out just in case. My almond lab friend was pretty alarmed we even tried it. Apparently this kind of haywire genetic mixing happens a lot in Prunus species and it's not unusual for a fruit to look like a mix of different fruits that we normally think of as distinct.

Most of us think we've got nature pretty well figured out, but it always surprises me just how amorphous and unpredictable biology really is.

Experimental Apple Pie v.2

I'm new to baking but I've gotten a lot of practice this fall - and still haven't made a dent in the more than a bushel of apples, and 10-plus pounds of Long Island cheese pumpkin I bought a month ago ($15 at a farm stand clearance!).

A quick Google search and advice from a friend started me on a great apple pie recipe - though I'm not sure how it could taste bad with the amount of butter and sugar that's called for... At any rate, I tried leaving the skins on this time (since my apple sauce was much better with them). I'm happy with the result! Today's pie seems to taste more aromatic apple-y than previous ones and is largely dark red in the center, like pecan pie. Chewing on big pieces of skin wasn't a big deal, but I bet I wouldn't notice them at all if I cut each apple slice in two before baking.

I made bread from the cheese pumpkin before Thanksgiving and was happy with it (though I'm not sure it tasted any different than the canned stuff. This variety is supposedly the quintessential pie pumpkin and I was surprised that a fruit with such a dull, pink exterior could be so fluorescent orange on the inside. According to Wiki, it's actually a different species than "normal" pumpkins, Curcurbita pepo and maxima. Pumpkins, gourds, squash and zucchini are all just different varieties of a handful of species (the same way broccoli, cabbage and Brussels sprouts are all just different varieties of the same species). Cheese pumpkins, specifically, belong to the species C. moschata (along with butternut squash). At any rate, I'll be turning some of this frozen pumpkin into pie soon.

One way or another, I've got a few more prototypes to run through before I bring pies (and piles of apple butter!) to Christmas. Anyone have an easy gluten-free pie crust recipe?

Biodegradable = Scam

I saw a lot of good money spent on "biodegradable" cups, plates and trash bags this past week.

For those of you who've never had a tour of a landfill, nothing rots in a modern landfill.

Modern landfills permanently entomb trash within impermeable layers of rock and plastic sheeting (see pic.), compacting the refuse into a dense, anoxic environment that prevents the infiltration of water or air (and therefore any real amount of biological decomposition). This is a good thing! The last thing you want is for a city's worth of old batteries and diapers to corrode and seep into the groundwater. Completed landfills are sometimes covered in grass and converted to golf courses or parks, but trees can never be planted due to the disruptive impact of their deep roots.

I find the biodegradable sales pitch especially disingenuous when it comes to "compostable" plastic products made from corn. These plastics are only compostable under rigorous, professional conditions. If you throw them in any old pile, they'll be around for years just like corn cobs or wood.*

I don't see cutting down on landfill space as a big environmental priority at any rate (especially in a country with as much surplus wastelands as the U.S.). I'm a lot more concerned about slowing the paving over of our best wildlands and agricultural soil, and conservation that limits the oil and mining-intensive production side of consumption (as opposed to just figuring out how to throw out what we're done with).

Use it up, wear it out, fix it up or do without...

* Has anyone actually tried to compost these corn plastics? Did it work? What are your conditions?

Osage Oranges

Osage oranges are probably the most interesting thing I saw in the ~ 1,000 miles I've driven so far this week (that and that Hokies *really* like to decorate their cars).

The lime-green, softball-sized fruit littered the ground along backroads (particularly in West Virginia), where these normally nondescript trees grow in crowded rows of rusty, cluttered branches. These trees were commonly planted as thorny hedgerows in the 1800s, prior to the invention of barbed wire. Maybe the trees I saw were the remnants of old fences.

It's been hypothesized that the fruit of this tree were once dispersed by extinct North American ground sloth, elephant or horse species. There are a few giant fruit species that appear to have lost their co-evolved animal disperser (e.g. avocado, prickly pear and papaya). These marooned plants are sometimes referred to as "anachronisms." There's pretty good evidence that ground sloths were the natural disperser of Joshua trees in the American Southwest. Their extinction is leaving these plants in the lurch as climate change slowly moves their habitat away.

Native to Texas, Osage orange was one of the species planted throughout the Midwest and Great Plains by the U.S. government during the Great Depression to improve the environment and give the unemployed something to do. One of my friends once told me that tons of (now very large) walnut trees remain on marginal land in Indiana. I guess most people have forgot about them, but their high quality wood is ripe for harvest.

The twisted old Osage orange in my parents' yard finally keeled over this fall. Half the root system was dead but the thing still appeared to be alive when it began to shed its leaves a few weeks later. My siblings and I had some fun trying to cut into one of its fruits when we were young. Those things are impossibly sticky. I remember it took us about an hour to work our way into it with one of my mom's kitchen knives, which she was then forced to throw out.

My parents have been losing a lot of the old trees that I grew up with. According to their arborist, their soil has too many boulders to allow the trees adequate purchase. Tulip trees are springing up in place of a lot of non-natives, which is a pretty good trade. A couple old walnuts, a Paulownia and a massive cherry (the largest I've ever seen, ~4' dbh*) are on their slow way out. Good specimens of these species can be worth thousands of dollars in lumber and veneer wood. I've been egging my parents into trying to sell them before they completely collapse, but they're no doubt too gnarled and heartrotted to be worth anything.

A quick Google search suggests that no one has any interest in harvesting yard trees anyway. In addition to poor dimensions, urban trees are often filled with old nails, screws and fence wire - which may have become invisibly entombed a hundred years ago, but can kill when the mill saw encounters them.

*dbh = diameter at breast height (a standard forestry metric)

Wooly Mammoth Hunting Licenses

RE-POST FROM 2.2008*

I came across an encouraging article on the USDA-ARS website. They describe a project to develop perennial warm and cool season grasses to supply ranchers on the Great Plains with forage for their cattle year-round. Many of these varieties are based on native species, improved for standard agronomic traits such as ease of seed collection. Grass-fed beef is relatively green as it doesn't require fossil fuel-intensive corn and soybean feed and doesn't produce burdensome concentrations of manure**. The American prairie co-evolved with numerous (mostly extinct) herbivores in the first place, and in the end a grassland grazed by cattle isn't much different than one grazed by bison.

This reminded me of this old letter to Nature from a few years ago (Re-wilding North America). The authors argued that we could simultaneously restore North American ecosystems and conserve endangered species by introducing animals such as elephants, camels and lions to open preserves in the United States. North America had many native large mammals prior to human colonization (including several elephant, horse, camel and lion species). It's likely that the late colonization of humans with sophisticated technology drove this whole class of animals to extinction here as it had in Australia. The introduction of similar species from Africa, in their minds, would restore our native ecosystems to a more pristine and functional state (for example, they point out that the pronghorn antelope probably co-evolved closely with the now-extinct American cheetah).

I think their most interesting argument is that this project could increase the public's dedication to preserving wild lands in general. They cite that more people visit the San Diego zoo's wild animal park each year than the National Park system. They propose that humans have an innate aesthetic interest in watching large herbivores and that the dedication of new wildlife parks could be justified by introducing these animals (many hunting ranches are apparently already stocked with such animals in Texas). These new parks could be established in economically depressed regions to simultaneously benefit local communities and justify the preservation of large tracts of undeveloped land.

This reminds me of the recent Pennsylvania Wilds project, which was created to bring tourism dollars to rural PA, and largely revolves around the re-introduction of elk (for watching and highly-coveted hunting licenses). I think we should take this a step further. Cloning technology will soon*** allow us to produce reasonable facsimiles of many of the large mammals that our ancestors recently drove to extinction. It seems to me that if the United States can make room for wild populations of wolves, bears, bison and moose then it could certainly support other similar, formerly extinct species... or at least the likes of passenger pigeons. These resurrected organisms won't be identical to the animals we drove to extinction thousands of years ago. More often than not, they will be rough behavioral and morphological hybrids with existing species. I don't see why this should be a deal-breaker though. The authors of the Nature paper point out that the highly acclaimed re-establishment of the extinct Midwest peregrine falcon was really done by breeding other peregrine falcon subspecies from around the world. Not the same thing, but still very much worth it.

I think the reintroduction of charismatic extinct animals and the dedication of new wildlife parks could really energize the public to value wild lands and the lifestyle choices that preserve them. With all the inaction-inducing guilt usually associated with environmental awareness, I think it could be worth it to show that extinction isn't always forever.

*Because I spent all night writing a post about Osage oranges and realized I wanted to link to this idea. I have a few re-posts in queue from my old grad school blog (where I mostly complained about being in grad school)
**yeah, but inefficient = expensive
***Well, I think 10-15 years is an okay guess. The nitty gritty challenges of synthesizing and assembling large genomes are pretty daunting, but JCVI is making some impressive progress.

Did Beer or Bread Come First?

This is why I follow Rachel Lauden's blog.

The Omnivore's Advantage

I learned something pretty fascinating on Nova's "Becoming Human" series. You can watch it for free here.*

Many hypotheses have been suggested to explain how our species (H. sapiens) replaced neanderthals (our sister species, H. neanderthalensis) - e.g. we killed/out-competed them because we're just so smart and have such amazing technology and rich social lives. The scientists interviewed by Nova also put forth an idea I hadn't heard before that is both less self-serving and more interesting - we may have driven the neanderthals to extinction with our omnivory.**

According to the interviewed scientists, neanderthals were carnivores, adapted to hunt big game with handheld spears in social bands (possibly with effective language). In addition to oft-cited human technological skills (e.g. a handful of javelins is much safer and more efficient than a spear) and social skills (e.g. sophisticated language), humans had skinny bodies that required far less food. It's been estimated that the heavy stature, large brains and cold environment of neanderthals likely required 5,000 calories a day!

I would imagine that an incredibly effective way to drive a specialist animal (like neanderthal) to extinction would be to introduce a similar, generalist species (humans) that could eat just about anything - but preferred the same food the specialist ate.

Neanderthals (like wolves) would have been forced to follow migrating game. The additional pressure of climate change (e.g. repetitive ice ages) would affect the abundance and distribution of prey species dramatically. Normally, it should be fairly simple for a predator to follow changing game distributions around a small continent, but humans could upset this balance.

Picture a small, warm valley in Northern Europe that supported enough deer, wild cattle and sheep to support a band of neanderthals. If they reproduced too much (or another band of neanderthals moved in), the now-unsustainable harvest of prey would force them to disperse to better hunting grounds, and in time, with relaxed predation, the prey would likely repopulate the valley.

But if a band of humans moved in, they may not only help over-harvest the big game, but also refuse to leave when the game ran out. Maybe there's still good year-round living to be made on rabbits, seeds, fish, grubs and berries. And while they're out gathering, they'd certainly help themselves to any of the (now rare) big game that they came across.

While neanderthals were wandering around Europe, becoming increasingly desperate, humans may have been getting fat and having babies.

It also was pretty interesting to hear how climate change in general seemed to shape our species and how our culture and technology radically changed our relationship with our environment. I thought it was pretty fascinating to hear that megafauna extinction was correlated with date of first human arrival. Large African animals weren't driven to extinction because they co-evolved with humans and only a few large European and Middle Eastern animals (e.g. neanderthals) were driven to extinction since they first ran into us relatively early. Large animals in North America and Australia were discovered suddenly by extremely modern humans and were apparently wiped out accordingly.

Finally, it occurred to me that almost all the animals that we routinely compare ourselves to (e.g. most medical research animals and livestock) share something in common that's different from us - they're all adapted to temperate and Mediterranean climates. Humans, on the other hand, are a tropical species. The Nova series also touched on a unique human adaptation that would surprise many of us. Humans are one of the only species on the planet capable of being active in extreme heat. Most animals are forced to rest to try to stay cool during hot, 100+ degree days. Although it's very uncomfortable and we use up a tremendous amount of water in the process, we're perfectly capable of remaining active.

This is seen in the practice of persistence hunting, which has been proposed to have been practiced by our ancestors in Africa and still occurs today. This strategy simply involves walking up to some large animal (like a big antelope) during the hottest part of a tropical summer day, and then tracking it after it runs away. The hunters repeatedly catch up to and scare off their prey (which, by the way, amounts to running a marathon under a 100+ degree sun). The prey never has a chance to rest long enough to cool off and eventually becomes incapacitated by overheating and is easily killed. Appropriately, humans are also adapted to long-distance running. I suppose any of us could still train to do this, though our light color phase individuals would get a bit of a sunburn...

The interviewed scientists also emphasized that while humans have existed for a relatively short time compared to other Homo species, our species appears to be uniquely flexible and adaptable. I wonder if this extends to our diet? I seem to remember hearing about a Pacific Northwest Native American group subsisting almost exclusively on mussels, and didn't the Mongols create one of history's greatest empires mostly on meat, milk and blood? Not to mention the heavily industrialized foods that many of us consume today. It kinda seems to me that humans can thrive on pretty much whatever food's available (not that all contribute equally to a long, enjoyable life!).

Think of our omnivory when you eat this week.
Happy Thanksgiving!

*Thanks for the open access, Nova!
**I'm in no way a paleontologist, so feel free to point out any errors

HOT Pepper!

The secondary focus of my research is the comparative metabolomics of the Solanaceae (i.e. I'm seeing what kinds of chemicals are present in different fruits in the nightshade family).

Our 2009 Upstate summer was waaay too cool and short for a number of our more tropical species and landraces* so I dug up and moved a dozen or so of them to the greenhouse to finish up. Our Latin/South-American chilies are finally about done.

I'm especially intrigued by our accession of Capsicum eximium, which is, as far as I know, a completely wild, undomesticated pepper. I would figure that it wouldn't be particularly hot or flavorful since these are among the first traits that humans improve when they start saving seed.

In the wild, peppers "want" to be eaten by birds (which digest the fruit without hurting the seeds) over mammals (which tend to chew the seeds to death) so they produce capsaicinoids, super spicy chemicals that only mammals can taste!

A recent PNAS study found that spicy subpopulations of a wild chili were attacked less by insects and a pathogenic fungus than less spicy subpopulations. Although this would suggest that peppers can protect their seeds from fungi and animals by being hot, the authors' previous study also found that plants that produced lots of capsaicinoids tended to have thinner seed coats - which are more vulnerable to animal digestion. The authors suggest that these selective pressures favor a population with mixed levels of spice. I would imagine that when peppers are routinely spicy, mammals would learn not to eat them, allowing some individuals to enjoy the benefits of thick seed coats (better germination after bird consumption) without suffering losses to mammalian herbivory (due to low spice).

As I collected the tiny, glossy red C. eximium fruit, I remarked to my co-worker that they looked like little candies. (Ironically, our yellow-fruited Peruvian aji variety is actually named "dulce.")

"Should I try one?"

My coworker laughed at me for the suggestion. I popped one into my mouth: a thin, shriveled little fruit less than half an inch long.

"It's like chewing on a piece of bark... there's no flavor at all....
oh wait! it's really flavorful!.. and a little hot!
it's pretty hot. hmm, it's getting hotter. uh, it might be really hot...
uh oh....."

I spat out the pepper and laughed as the spice burned across my tongue, which eventually went a little numb. I looked around, regretting I was away from my desk.

"Is this [greenhouse spigot] water "industrial" or can I drink it??"

It wasn't the hottest pepper I've ever eaten: that was one I mistook for a snow pea pod that left me flushed, out of breath and (for more than an hour) with a burnt throat.**

It was incredible though that a pepper as small as C. eximium's could be that HOT! I never would have guessed. I would need many dozens of them to equal the weight of a habanero or jalapeno (which aren't big peppers to begin with) It was really good too! Very flavorful. Would be great for chili.


* I have to plug Johnny's Seeds here. This "employee-owned" seed company operates out of Maine and produces appropriately cold-adapted varieties. We had tremendous yields out of multiple varieties of pepper and eggplant (which are notoriously cold-intolerant) in spite of our unusually cold and short, Northern summer. Our wild and heirloom varieties (that we got elsewhere) were a complete failure as of September.

** I feel that I should put this in the perspective that I love spicy food more than almost anyone I know. My mom never cooked spicy food when I was a kid, but I was known in my family for eating salads that were "gray" with black pepper and I want any restaurant cook who's cooking my Mexican or SE Asian food to feel personally challenged that they can't make it too spicy.

Slavery in Florida

Florida produces 90% of all U.S. supermarket tomatoes in the winter (not to mention citrus). According to Talk of the Nation, they also are dealing with the persistent, illegal practice of debt-bonded slavery in farm labor.

5% of Florida farm workers are estimated to suffer from this treatment. Workers have been shackled in the field, beat, locked in trucks at night and forced to fight each other. Unbelievable. I hope law enforcement down there is getting all the resources they need to end this.

Engineering Glaciers

Glacier Man describes the efforts of a retired civil engineer, Chewang Norphel, to create "artificial glaciers" to act as reservoirs in the Himalayas.

Norphel spent his career building roads and bridges in rural Asia, working closely with the locals and using locally-available materials. Toward the end of his career he began to focus on water scarcity as disappearing glaciers and streams were threatening Himalayan farmers with starvation.

Norphel noticed that the spring snowmelt was largely supplied by large rafts of ice in forested areas - where shade prevented thaw until temperatures were warm enough to plant crops. He realized he could augment this process by building shallow reservoirs to collect and hold winter precipitation until the spring thaw - delivering water to the fields at the exact correct time for planting. Each of these artificial glaciers (he's built 10) costs 6-20 thousand dollars and unlike more expensive cement reservoirs, are capable of recharging the groundwater.

Norphel's glaciers currently supply water to 10,000 people, doubling their crop yields and allowing the production of valuable crops such as barley and potatoes. Although climate change is a serious threat to this very effective, locally-appropriate technique, he sees great opportunities in other dry, mountainous regions such as Afghanistan and Turkmenistan.

"Eating Animals"

I listened to Jonathan Safran Foer discuss his new book, Eating Animals, today on On Point.

What I've heard to date suggested he would be an irrational extremist, but on the radio at least, he was calm, logical and (when it came to the economics and logistics of agriculture) accurate.

He asserted that the treatment of animals in industrial agriculture falls below the ethical standards of all people, that people would be revolted if they actually understand how animals are treated and that the only solution is to become a vegetarian (as low-intensity agriculture isn't productive enough to keep 6 billion people in beef and chicken).

A lot of people seem to be freaking out about his book, but his appearance on the radio was reasoned, consistent and offered one possible answer to my question.

He said that he's never met someone who was a proponent of factory farms, but I think that may just reflect his social circles. I'm all for legislating the humane treatment of animals, but I don't think that's mutually exclusive with high intensity animal ag.

"We are not anti-dryer; we are pro-clothesline"

Grist has a nice interview with Alexander Lee, founder of Project Laundry List, on his efforts to promote eco-friendly clotheslines (over electric dryers). Apparently HOAs (home owners associations) are the primary obstacle.

Why anyone would be willing to live in a neighborhood where a HOA can tell them what to do with their property is beyond me...

Pretty Plant Diseases

Our local Ellis Hollow blog has some nice poinsettia pics. As I mentioned earlier, a plant disease is responsible for bushy, heavily-flowered (well, they're not really flowers) varieties of poinsettia.

Phytoplasma infections commonly cause symptoms of phyllody (the transformation of flowers into leaf-like structures) and virescence (the production of green flowers). Much like virus-induced tulip color breaks*, phytoplasma infection of poinsettias is commercially valuable.

Modern tulip color breaks (irregular stripes) are actually caused by a genetic mutation (not viral infection), which is much better for long term health of the plant. I don't know if similar genetic improvements have been made to poinsettias.

*The most famous color break tulip, Semper Augustus (pic), marked the peak of the speculative bubble known as tulipomania. In one famous account, a single tulip bulb was supposedly sold for "two lasts of wheat, four lasts of rye, four fat oxen, eight fat swine, twelve fat sheep, two hogsheads of wine, four tuns of beer, two tons of butter, one thousand pounds of cheese, a bed, a suit and a silver cup!"

What's your Gardening Geography? [UPDATED]

If you're like me, you grew up consulting the USDA hardiness zone map to forecast what plants could be successfully grown in your climate. These zones are defined by the average minimum temperatures experienced in a given region of the country. E.g. plants that are hardy (can survive) to 15-20F could be expected to survive in zone 8 cities such as Seattle or Dallas. An updated map is currently in the works to reflect the recently warmer climate and the extent to which major urban areas retain heat.*

You may have noticed that very different climates are included within the same zones. As an extreme, Wikipedia points out that both the Shetland Islands and southern Alabama sit on the border of zones 8 and 9. Hardiness zones don't account for numerous critical factors, including average high temperatures, rainfall patterns, humidity, probability of extremely cold temperatures and the protective effect of snow cover.


Such fine-scale differences in microclimate are influenced by both topology and regional weather patterns and account for much of the regional variation in ecosystems. The EPA currently has a project (which I'm fairly obsessed with) that is working to map and define ecoregions across the United States by geography, climate and native vegetation. It's an awesome resource for native gardeners or anyone who wants to appreciate their local wildernesses on a more holistic, "systems" level.

Sunset Books has been including more than average minimum temperature in their gardening recommendations for years. Originally specializing in the diverse gardening habitats of the Pacific and Intermountain West, they now include specific gardening recommendations across the U.S.

According to their Plant Finder, Boston is hot and humid enough in the summer (yet not too cold in the winter) for a native North American palm tree. Who would have thought?

UPDATE: here's the provisional updated hardiness map. yikes!
*I keep hearing reference to some study that predicts global warming will bring Virginia temperatures to upstate New York within a few decades. As someone who loves cold, snowy weather, I desperately hope this isn't true!

Tomatoes are Vegetables, Legally

The official USDA Definition of Specialty Crops found its way into my mailbox this week.

"The terms used to describe these specializations derive from millennia of common usage and are sometimes at odds with botanical nomenclature. For example, vegetables are described as herbaceous plants of which some portion is eaten raw or cooked during the main part of a meal. Fruits, for horticultural purposes, are described as plants from which a more or less succulent fruit or closely related botanical structure is commonly eaten as a dessert or snack. By these definitions, plants such as tomato, squash and cucumber are considered vegetables despite the fact that the edible portion is defined botanically as a fruit. The delineation of plants by common usage was legally established in 1893 by the unanimous U.S. Supreme Court decision in the case of Nix vs. Hedden."

It's never occurred to me that plant names could have legal definitions in addition to scientific and colloquial ones, but there you go!

Winter's A'Coming

The last of the Canada geese are straggling through Central New York and my harvest is officially finished. I've finally processed the last of my fall produce, grown and bought. Boxes of chili peppers, corn, tomatoes, apples and pumpkin are now all cooked, canned, dried and frozen.

Our experimental farm plots are all plowed and planted in cover crops. We picked the last of our corn towards the end of October. We couldn't have asked for a more perfect fall day. We busily shucked and gossiped our way down the range, occasionally looking up from our hands to take in the cold, blue sky and surrounding forest of straw-colored corn plants. Most of our colleagues were less fortunate the previous two weeks, picking their corn in sub-40F weather as their bags filled with sleet. I was thankful to be wearing gloves when we hit patches riddled with a pink fungus known for the production of carcinogenic and brain-melting mycotoxins.

I'm ready for our current warm stretch to subside. I'm amazed that some insects aren't dead or hibernating yet. I actually saw a 6" dragonfly last weekend. The Pacific salmon and steelhead are thick in the famous tributary of Lake Ontario, the Salmon River, but I don't think our local Atlantic salmon and lake trout will start climbing the rivers until we get some more cold rains.

Here's to some snow!

Fun with Dumpster Diving

I enjoyed some leftover soup and bread tonight from my friend's grocery store job. It's a shame how much expired food normally gets thrown out in our food system. I remember my fellow grad students' exasperation that expensive bell peppers are regularly thrown out as soon as they begin to wrinkle.

I met them for lunch outside the MU one sunny day while aspiring student council candidates buzzed around us.

One particularly affable undergrad approached us to explain why he was the man for the job. He noticed the big bag of bagels on the table and cheerfully accepted an offer for some free food.

"Where are these from?" the young politician asked, reaching into the bag.

"They're from, uh, well, from behind Noah's, they're....
dude, they're from a dumpster."

His face slumped in disbelief as my friend sheepishly explained that they were found wrapped completely in two clean bags - and were therefore perfectly edible.

He quietly declined and moved on to the next table.

In Defense of Feedlots

Could concentrated animal feeding operations (CAFOs) be the key to sustainability?

"As an example, one dozen eggs, transported several hundred miles to a grocery store in a tractor-trailer that can carry 23,400 dozen eggs is a more fuel-efficient, eco-friendly option than a dozen eggs purchased at a farmers’ market (4.5 times more fuel used) or local farm (17.2 times more fuel used)."

hat tip: AgWired.


Meanwhile, in Kansas, urban pioneers try to bust city anti-ag ordinances.







hat tip: Ethicurean.

The Third Way for Agriculture

Finally! Someone describes a sensible marriage of industrial and organic agriculture.

"There are many promising avenues to pursue: precision agriculture, mixed with high-output composting and organic soil remedies; drip irrigation, plus buffer strips to reduce erosion and pollution; and new crop varieties that reduce water and fertilizer demand. In this context, the careful use of genetically modified crops may be appropriate, after careful public review."

Sound familiar?

The Real Threat of Genetic Engineering

Opponents of genetic engineering have displayed a real failure of imagination. The threat of genetic engineering in the hands of corporations is nothing compared to the hands of the people.


Though corporations are incredibly powerful, they are also incredibly visible and incredibly predictable. The big ag biotech companies all operate out of enormous industrial parks, are inhabited by thousands of people who care just as much about their communities as you do, and advertise what they're working on incessantly.

Capitalism is a powerful tool for the generation of wealth, and it's simply a matter of regulation and redistribution whenever a society holds non-laissez faire values. Most instances of corporate "crime" are no more than the failure of a government to enforce the values that its people expect. I don't know anyone who thinks that the U.S. government is as effective as it could be, but overall it really does an excellent job through regulatory organizations such as the USDA, EPA and FDA.

You may have a philosophical axe to grind against Microsoft, but the reality is they're always being watched and they get sued when they step out of bounds. Individual hackers concern me a lot more since they have extremely diverse motivations and are completely under the radar until something goes wrong.

There is currently a very active amateur genetic engineering movement. By all accounts, their accomplishments have been laughably rudimentary - on par with mid-level college biology labs - but it won't be this way a few years from now. The equipment, techniques and reagents necessary for genetic engineering are rapidly advancing in effectiveness while their costs crater (e.g. the cost of sequencing DNA is falling faster than Moore's Law).

What will happen when anyone can create, manipulate and release life?

I don't think we can predict the ramifications of this, but it will certainly be at least as revolutionary as our burgeoning personal integration into the Internet. The cutting edge of genetic engineering is quickly climbing into the science fiction realm,* is mostly open access, and can be well approximated with homebuilt equipment and common chemicals. I can't imagine the solution to this, but we'll have to start thinking about it pretty soon...

* Have you seen this? Scientists have removed the disease-causing genes from the HIV virus, and used it as a vehicle for gene therapy, possibly curing two children of a neurodegenerative condition.

The Myth of Monocultures

Brendan sent me a link to the new PBS video special based on Pollan's The Botany of Desire. Ironically, I had been eyeballing the same book on my shelf the past few weeks wondering if it was due for a re-read.

The PBS special was very well done and I definitely recommend it.

The last 15 minutes though (an uninformed tirade against modern agriculture), were unwelcome and irritating. One telling moment was a local ag scientist lamenting the "tragic" public rejection of the environmentally-friendly Bt potato, followed by more fear-mongering by a partisan lobbyist.

Pollan should limit his lectures to topics he understands - which wears thin as he waxes on the horrors of monocultures. Plants (including crops) are in a continual arms race with pests and pathogens. The plants keep finding new ways to protect themselves while the parasites "keep trying to pick the lock." Picture a landscape filled with many different kinds of potatoes. According to the classic version of this story, a parasite that stumbles upon a new way to break into a certain potato variety may wipe out all individuals of this variety but it won't kill EVERY potato on the landscape.

The problem with this story is that plants varieties that look very different don't necessarily have different disease and pest resistance genes. Just like humans, which are known for tremendous phenotypic diversity, can be extremely susceptible to the same flu and HIV germs across all ethnicities, all the multicolored potatoes in the above picture may be similarity susceptible to diseases like late blight.

It's not so surprising that crops are notoriously vulnerable to parasites when you meet their wild relatives. The fruits and grain of the undomesticated relatives are usually barely edible - tiny, fibrous and full of poisons. It should be no surprise that the same qualities that humans love in their food (lots of easily-digested calories) are appreciated by many other creatures as well. Plant breeders have countered this inherent susceptibility by introgressing (moving) key resistance genes from wild relatives of crops into the crops themselves. This process has actually made modern industrial tomatoes more genetically diverse than either traditional Latin American or U.S./European heirloom varieties (although the traditional and heirloom varieties look more diverse).

Theoretically, it would be useful to maintain crop populations with diverse resistance genes. The industrial application of this (multilines) invovles breeding many different versions of a favorite crop variety that are identical except for their resistance genes. As appealing as this idea is, it hasn't really worked out in the real world. The alternate approach (pyramiding) seems to be more effective. Here, many different resistance genes are combined into a single crop variety. Pests and pathogens may be able to overcome a single gene at a time, but it's usually almost impossible to simultaneously overcome several.

PBS' The Botany of Desire also makes a lot of Bt resistance developing in insects exposed to genetically-engineered Bt crops, but this is nothing new. Insects and pathogens develop resistance to all kinds of pesticides - whether they're natural plant chemicals, artificial sprays, or genetically-engineered genes.

Evolution is a fact of life. The pests and pathogens will continue to adapt, and they will eat up our crops if we don't keep ahead of them. It's a problem you can never completely solve - which is good for me and my scientist colleagues!

Division of Leaves

This picture shows some common tomato leaf shape mutants. Mutants (which generally are each broken at a single gene) are a really powerful tool for figuring out what individual genes actually do. In this case, they help us figure out how different plants are able to produce their extraordinary diversity of leaf shapes.

The top left image is a normal tomato leaf. Tomatoes have compound leaves with about 7 leaflets (which themselves can be further divided) with some little flat extensions of leaf tissue in between. Mutations in individual genes can force the leaf to bifurcate further or form one single, continuous blade.

Plant scientists have made some great progress figuring out how plants regulate leaf shape. Much of it is controlled by the plant hormone auxin. Scientists have found that if they add microscopic drops of pure auxin to baby leaves as they're developing, additionally leaflets will form at each drop. Additionally if they leave a long line of auxin, a flat leaf blade will emerge along the entire line. In normal plants, these spots form on their own as the leaf grows (and additional spots form in between as they're stretched apart). This way, tomatoes can form leaves with a consistent shape whether they're baby 3-leaflet leaves or large 9-leaflet ones.

This suggests that compound leaf development requires isolated spots of auxin. Accordingly, genes have been discovered that are either required to initiate these spots or to inhibit auxin in between the spots. Using genetic engineering techniques to increase or decrease the expression of these genes has predictable results and can produce non-compound leaves that are completely surrounded by a continuous blade, or that lack blades completely (and look like cactus spines!).

Both tomato and its sister species, eggplant, have relatives with leaves that have different levels of complexity. Different versions (alleles) of these genes have been found in these species. Ultimately these genes are translated into proteins, which react with other proteins and DNA to control leaf morphology. Some of these proteins have been found to vary in their binding affinity among species - e.g. a protein that positively regulates large numbers of leaflets is "stickier" in a complex-leafed species, interacting more with its partners and making a stronger "make leaflets!" signal.

So why do plants go through so much trouble to create such a variety of leaf shapes? This is still an open question, but leaves of different dimensions, with different degrees of division, lobey-ness and serration likely differ in temperature conduction, gas exchange, water relations, herbivory, disease susceptibility and light interception.

I love this black and white picture,* which illustrates how leaves vary with the environment. The big leaf on the left is a red maple grown in Vermont. The tiny leaf on the right is the same species, but grown in Florida! The color picture is my conception of what a "red maple" looks like - and reflects that my youth was spent in between these two latitudes!

















*Royer at al. 2008. New Phytologist. 179: p.808-817.

Flowering Bulbs and the Atom Bomb

Our local colchicums bloomed recently (at least before it started snowing)...

Colchicum is a genus of flowering bulbs that's native to the Mediterranean coast. This picture shows Colchicum autumnale, aka the "autumn crocus," which, predictably, blooms in the fall and looks like a crocus.

This genus is also known for producing the poisonous alkaloid, colchicine. Used in various traditional remedies, this chemical has anti-inflammatory properties and prevents cell division by (for those of you who remember your basic biology) binding to tubulin and therefore preventing the assembly of the microtubule scaffolding required for mitosis.

The ability of this chemical to prevent cell division (but not DNA replication) can also be used to double the number of chromosomes within a plant cell, which has various applications in plant breeding. Although we can now use genetic engineering to add, remove or change genes in pretty much any way we want, traditionally, the only way to find new versions of genes (and therefore new phenotypic traits) was to wait for one to mutate naturally or use chemical tricks to induce mutations.

Many of our most important grain varieties were intentionally mutated with chemicals and ionizing radiation half a century ago. Because the mutations are random, they sickened or killed almost all of the exposed seedlings, but, just like occurs with natural selection, a few happened to change in beneficial ways. One such induced mutation is dwarfism, which produces short, strong plants that can carry heavy seed heads without falling over. In addition to mutating plants within controlled laboratory experiments, one of my professors told me that they actually left bags of wheat and corn seed on the decks of test ships (like those in this picture) when the U.S. government tested the atom bomb on Bikini Atoll!













Some activists have begun to refer to these mutated plants as "hidden GMOs." However, unlike true genetic engineering, "mutation breeding" breaks DNA in exactly the same types of ways that produce natural mutations - it's just much faster.

Over 2,500 of our crop varieties have been improved with this "mutation breeding." Currently many companies are using this technique to generate novel genetic diversity while avoiding the stigma and regulatory obstacles associated with genetic engineering - especially for crops like sunflower, which are often planted within pollination range of their wild relatives.

Science Reporting Ethics

Do you have any thoughts on the ethics of blogging about scientific presentations?

The issue (for you non-scientists out there) is that scientists generally give presentations (whether to departments or international meetings) with the assumption that what they display, say or imply probably won't travel very far outside the room.

So, how do you report something that isn't meant as public knowledge?

For me, it's not so much an issue of presenting "scoopable" data out to the wider world because I generally blog from ideas (usually anecdotal) given in presenters' introductions - which I try to tie into other ideas I've been exposed to. What I don't want to do is imply that the author has opinions they didn't state (or don't want to announce publicly), not give credit where it's due, have to approach every person and ask them if it's ok or never talk about stuff presenters say in the first place.

Any thoughts?

Paw Paws!

Whenever I wandered through the hills and swampy bottomlands during my youth, I always kept an eye out for pawpaws. I never found one of these fascinating North American "bananas" until today - at our University orchard store.

Asimina triloba is a small understorey tree graced with large, dark green leaves that allude to the primarily tropical home of its family. The pawpaw received its name from an early Spanish explorer who confused this plant with the tropical papaya.

In spring, pawpaws produce small, maroon flowers. Although these flowers contain both male and female parts, they are self-incompatible. Some botanists estimate that fewer than 1% of flowers ever produce fruit! Inefficient pollination (plus poor storage properties) limit commercial production of this fruit.
(although Kentucky State is working hard to change this)

Poor pollination efficiency may also arise from the evolutionary strategy that the pawpaw takes. Some flowers in the pawpaw family (e.g. white-flowered Asimina species) pursue an "honest, rewards-based" strategy, exuding sweet-smelling, fruity scents that attract and feed beetles. Maroon-flowered species (like the pawpaw itself), instead exude fermented/decaying scents, mimicking rotting meat in an effort to trick flies into pollination. Some farmers have attempted to attract more flies by hanging rotting meat from their trees! (but hand pollination is recommended).

I left the green fruits in a paper bag to ripen until they were mostly black and smelled faintly of pineapple and licorice. Like thin-skinned avocados, the inside of the fruit contained a few large seeds and a custard-like fruit that tasted kinda like mango.


I put the seeds in the fridge to see if I can break dormancy and germinate them.





Charles Fergus. Trees of Pennsylvania and the Northeast. 2002.