Replacement coffee

Commercial farmers of perennial crops have an inherent problem.

The cheapest, most efficient, and most cost-effective method of growing something where the roots (or the entire plant) persists from year to year -- which includes fruits, nuts, and tropical products like coffee and cacao -- is to plant a large quantity of a single variety of plant.  The difficulty is that the plants are therefore closely related genetically, if they're not out-and-out clones, and susceptible to the same pests and diseases.  It's what did in the Irish potato farmers during the 1840s and 1850s; late blight (Phytophthora infestans) wiped out the single-variety potato crop five years running, resulting in the Great Famine in which a million people starved to death and another two million left Ireland for good, one of the largest exoduses from a single country in the history of humanity.

This is increasingly the situation being faced by the people who raise bananas.  Virtually all the bananas produced commercially are a single variety -- the Cavendish banana -- all descended from root cuttings of a plant from Mauritius that was in the greenhouse of the Duke of Devonshire.  Those cuttings were sent first to Samoa and other islands in the South Pacific, and thereafter to the Canary Islands, West Africa, and South and Central America, where the variety was found to be resistant to a fungal infection called Panama disease that had wiped out the previous main cultivar ("Gros Michel"). 

The problem is -- as we're seeing from COVID-19 -- pathogens have a way of staying one step ahead of us, and now there's a strain of Panama disease that kills Cavendish bananas.  Unfortunately for those of us who, like myself, love bananas, there is no obvious next strain to turn to.

The other plant in a similarly dire situation is -- and I hate to bring this up -- cacao.  Chocolate producers are fighting an increasingly long list of pests and diseases that target cacao plants, which are notoriously fragile and easy to kill.  As with banana growers, there is no good option for cacao farmers other than to fight the pathogens and insects when they show up and hope for the best.

Hearteningly, the situation is a little better with another of the world's most beloved crops, which is coffee.  

[Image licensed under the Creative Commons Julius Schorzman, A small cup of coffee, CC BY-SA 2.0]

In fact, this is the reason why the topic comes up; an article in Nature a couple of weeks ago looks at a different species of coffee (Coffea liberica) that shows real promise in avoiding some of the difficulties of growing the two main varieties, arabica (Coffea arabica) and robusta (Coffea canephora), which make up (respectively) about 55% and 45% of the commercial coffee in production.  The plants have better heat and humidity tolerance, and good resistance to coffee leaf rust and coffee wilt disease.  Liberica coffee (often called "excelsa" in the trade) was initially discounted because of the quality of coffee it produced, but that seems to be because the larger seeds have to be processed a little differently or they lose a lot of their flavor.  Dealt with correctly, liberica coffee has (according to the writers):

...a mild, smooth, pleasant-flavoured coffee of low to medium acidity and low bitterness, as per historical accounts.  Tasting notes include cocoa nibs, peanut butter, dried fruits, Demerara sugar and maple syrup; and for samples from South Sudan, there are notes of raspberry coulis, figs, plums and milk chocolate.

All of which is awesome but a little mystifying to me.  You probably know that there are people called "supertasters," who have a far greater acuity in their senses of taste than average, and who can pick out all the delicate nuances of taste in things like coffee, chocolate, wine, and so on.  I, on the other hand, am the opposite.  I'm a stuportaster.  I have two taste buds, "thumbs up" and "thumbs down."  Presented with most cups of coffee, my response is "coffee good, want more."  (The rest of the time my response is "coffee bad, no thanks.")  I do the same thing with wine, much to the dismay of the sommeliers when we visit wineries, who love nothing more than blathering on about the wine's nose and flavors and notes and finish, and do not appreciate a dolt like me who pretty much just drinks it and looks around for a refill.  So while I'm glad there's someone around who can pick out notes of Demerara sugar and raspberry coulis in their morning cup of coffee, for me it kind of starts and ends with "me like it lots."

In any case, it's encouraging that the coffee farmers may be able to escape dire situation being faced by owners of banana and cacao farms.  It's bad enough facing the prospects of losing two of them; losing all three would just be catastrophic, even for people like me who only have two taste buds.

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Fruits and vegetables

What is the fascination creationists have for the produce aisle?

First we had Ray Comfort claiming that bananas were "the atheists' worst nightmare" because we for some reason were supposedly befuddled by the fact that bananas are "perfectly shaped to fit into the human hand" and had a "non-slip surface," so they must have been created that way by an intelligent deity.  After Comfort was subjected to ridicule on social media at a level that would induce most of us to change our names and have our faces surgically altered before being willing to go out into public again -- I'll leave it to your imagination as to what other objects people informed Comfort were "perfectly shaped to fit into the human hand" -- you'd think the creationists would say, "Okay, maybe that's not the best argument we have."

But no.  Creationists, as a whole, seem to think that if at first you fail miserably, you don't just try try again, you beat the idea unto death with a blunt instrument.  And no one is better at that strategy than Kent Hovind, who is famous not only for specious arguments for young-Earth creationism but for spending ten years in federal prison for tax evasion.

Hovind seems to think that the way to support Ray Comfort's argument is to find other fruits and vegetables that are "the atheists' worst nightmare."  First, we had lettuce:

How could lettuce evolve slowly by chance and from what?  How many trillions of intermediate steps would there have to be to go from a dot of nothing to a living lettuce plant?  Is there any scientific evidence besides lines on paper?

Yes, there is.  Thanks for asking.

Then there were grapes:

How could a grapevine… evolve slowly by chance and from what?  Wait till you see what they teach on the internet that the grapes evolve from.  You won’t believe it… 

How could it happen by chance and from what?  How many trillions of intermediate steps would there have to be to turn a dot of nothing into a grape?  Isn’t that what they teach?

No, it isn't.  Thanks for asking.

Because that was such a wildly successful line of reasoning, Hovind turned to celery:

How could celery have evolved slowly by chance, and from what?…  I would like some hard scientific evidence.  What is the ancestor of celery if it wasn’t celery?  What was it?  And if it was something other than celery, please tell me how it changed. 

How many trillions of intermediate steps would there have to be to go from an amoeba to celery?  I would say it would take a lot.  I would like to see what’s the evidence is for that…

That is going to be problematic, because celery didn't evolve from amoebas.  But once again, thanks for asking.

So what about... broccoli?

Broccoli.  How could broccoli have evolved slowly by chance?  I would like an answer to that.  A very simple answer.  How many trillions of intermediate steps would there have to be to change from an amoeba... to broccoli?  Is there any scientific evidence for these supposed changes that you guys believe in — capital B, believe? 

Evolution is a religion.  Is it more logical to believe that maybe broccoli was created by a really smart Creator?

Hovind seems to like amoebas almost as much as fruits and vegetables.  Maybe he doesn't know about any other life forms, so that's why he keeps coming back to those.

To wit, last week's installment, wherein we hear about oranges.  And you'll never guess what his argument is:

You think all those oranges, and those trees that are producing it, and the dirt that’s holding it all came from a dot of nothing that exploded 13.7 billion years ago?  Whodathunkit.  That’s a new word I made up. 

How many trillions of intermediate steps would there have to be to go from a dot of nothing to an orange tree, and where is the evidence?  Is there any scientific evidence for all these supposed changes you guys talk about?…  Could it be more logical to believe, maybe, the orange tree was created by a really smart Creator?…  That’s the most logical conclusion.

 Of course, what all this boils down to is the argument from ignorance; "I can't imagine how this could happen" = "this didn't happen."  Evolutionary biologists and geneticists have a very good idea about how all of these organisms evolved (in most of these examples, with significant help from artificial selection by humans), and Hovind is only claiming this because he hasn't bothered to read any of the scientific papers explaining in great detail the answers to all of these questions.

[Image is in the Public Domain]

And I swear, if I hear one more time that the Big Bang Model says that "a dot of nothing exploded and made everything," I'm going to punch a wall.  For fuck's sake, if you're going to blather on about something, at least read the Wikipedia article first, if more technical treatments are above your head.  If you can't be bothered to do at least that much, allow me to direct you to the definition of "straw man argument."

Oh, and Kent?  You did not make up "whodathunkit."  I can remember my dad saying that back in the mid-1970s when I was in high school.  But given your determination to misrepresent and play fast and loose with scientific claims (not to mention your IRS return), I don't suppose there's any reason to expect you'd be more honest about other stuff.

But you have to wonder where he's going to go now.  Artichokes?  Mangoes?  Okra?  Pomegranates?  Bok choi?  The possibilities are endless.  It'd be nice, though, if he could change the rest of the argument, because it's getting tiresome to read, "So, consider _____.  Could that have come from a dot of nothing 13.7 billion years ago?  What's the evidence?" etc. etc. etc.  He's rung the changes on this one enough, don't you think?

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This week's Skeptophilia book recommendation is a classic: Richard Dawkins's The Blind Watchmaker.  This book is, in my opinion, the most lucid and readable exposition of the evolutionary model ever written, and along the way takes down the arguments for Intelligent Design a piece at a time.  I realize Dawkins is a controversial figure, given his no-quarter-given approach to religious claims, but even if you don't accept the scientific model yourself, you owe it to yourself to see what the evolutionary biologists are actually saying.

[If you purchase the book from Amazon using the image/link below, part of the proceeds goes to supporting Skeptophilia!]

Yes, we have no bananas

Yesterday a student asked me, "Is it true that you can die from eating too many bananas?"

I responded, "You can die from eating too much of anything.  How many bananas are we talking about, here?"

She said, "Seven, is what I've heard."

That sounded pretty unlikely to me, and I said so.  "What about eating seven bananas could be dangerous?"

"You'd die because so much potassium would be toxic," she said. "My brother told me he heard that from a friend."

Sketchier and sketchier.  One of the functions of your kidneys is to keep the levels of sodium and potassium in your blood within an acceptable range, and I couldn't imagine that a few too many pieces of fruit was all it took to overwhelm the system.  So I said I still thought it seemed implausible, but told her I'd look into it.

And lo, it turns out that this claim is making its way around.  In fact, BBC News Online ran a story just a few days ago entitled, "Can Eating More Than Six Bananas at Once Kill You?"  And this once again illustrates the truth of Betteridge's Law, which says that "Any headline that ends with a question mark can be answered by the word no."

[image courtesy of the Wikimedia Commons]

The most bizarre part about all of this is that it was stated, right there in the article, that the origin of the urban legend (if I can dignify it even with that name) was British actor and comedian Karl Pilkington, who made the statement in a conversation with fellow comedians Ricky Gervais and Stephen Merchant.

"Before when you were talking about bananas," Pilkington said, "I had that fact, about if you eat more than six, it can kill you.  It is a fact.  Potassium levels are dangerously high if you have six bananas...  I saw a bowl of bananas.  There's six bananas there.  You know why there's only six?  Seven would be dangerous."

And for some reason, enough people didn't know he was joking that the whole thing has now gone viral.

Can I remind you once again that Pilkington is a comedian?  I.e. a person who makes a living exaggerating the truth, or simply making shit up, to be funny?

And the BBC News Online is not helping.  Although later in the article they do quote Catherine Collins, a dietician at St. George's Hospital in London, who confirmed that seven bananas isn't going to kill you, there is an unfortunate tendency of people to read only the headline and the first couple of paragraphs of an article and decide that's all they need to know.  And by the fourth paragraph, you're still left thinking that your life is in danger from Toxic Death Bananas.

"It would be impossible to overdose on bananas," Collins said, way down near the end of the article.  "You would probably need around 400 bananas a day to build up the kind of potassium levels that would cause your heart to stop beating."

Well, I'm no dietician, but my general impression if that you eat 400 bananas in a single day, you're going to have way more problems to worry about than potassium toxicity.  And given that she phrased it this way, I'd be willing to bet that even amongst the readers who got this far in the article, there were still some who read Collins's statement and focused only on the words "EAT BANANAS POTASSIUM HEART STOP BEATING" and missed entirely the words "impossible to overdose."

So thanks to an offhand comment from a comedian, we now have another loopy idea to add to the list, joining ones like Daddy Long-Legs Are Deadly Poisonous But Have Weak Fangs, and Don't Throw Rice At Weddings Because Birds Will Eat It And Then Explode.

In short: there is no reason for bananaphobia.  Seven seems excessive, honestly, but if you'd like to pig out and eat the whole bunch, have at it.  And the other takeaway is: don't learn your science from comedians.  They lie sometimes.