Why the World's Most Popular Wine Grapes Are Vulnerable to a Pandemic

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When you're in the wine shop looking for the right wine to pair with your meal or bring to the party, the variety on the shelves seems rich and diverse, their taste influenced by the grape, soil, climate, and age. Among the most famous are the French "noble wines"—cabernet sauvignon, merlot, pinot noir, chardonnay, riesling, and sauvignon blanc—so called for being associated with high quality and easy growth in a variety of places.

But it turns out that many of the most famous grapes in the world are like nobility in another way: They're as inbred as a royal family, and have been for hundreds—and in some cases thousands—of years.

"Scientists are getting really concerned that this is setting up the perfect scenario for a great pandemic," Kevin Begos, whose new book, Tasting the Past, explores the history, archaeology, genetics, and future of wine, said at a recent book release event in New York City. They fear that a single merciless pathogen could wipe out many grapes around the world in the same way that a single fungus, Phytophthora infestans, eradicated the variety of potato common across Ireland in the 1840s, causing the great famine.

The vast majority of wine produced across the world derives from a single grapevine species: Vitis venifera. The domesticated grape has thousands of varieties, and quite a lot of genetic diversity among them, according to a 2010 paper in PNAS that analyzed genome-wide genetic variation of more than 1000 samples of V. vinifera subsp. vinifera and its wild relative, V. vinifera subsp. sylvestris. But that's not true for all grapes: Nearly 75 percent of cultivars had a first-degree relationship to at least one other. They were either parents or children.

The most popular commercial wines are made from a handful of these inbred grapes. Sauvignon blanc, for instance, has a first-degree relationship with cabernet sauvignon, cabernet franc, and chenin blanc, among many others. That genetically cozy family isn't unusual. You see it all over the grapevine.

Another problem is how grapes reproduce in vineyards. Instead of pollinating these hermaphroditic plants or growing them from seeds, as might happen naturally, grape growers generally make new plants from cuttings of existing ones, essentially cloning the same vines over and over.

They use this method to produce consistent flavor quality—and it's nice to decant a bottle of your favorite wine and know what to expect with the first sip. But this practice has kept some popular grapes in relative genetic stasis for a long time. Take pinot, parent of chardonnay and gamay, which has been cloned for 2000 years. Genetically, it's remained virtually unchanged—but the organisms that prey on it have not. "All those insects and pathogens and mildews that attack grape vines have been evolving," Begos said. "And they always figure out new ways to attack the grape vines."

Despite the wide use of pesticides—in the last 10 years, 260 million pounds of pesticides were put on wine grapes in California alone—"the industry is losing the arms race to the pathogens," Sean Myles, an author of the 2010 PNAS grape genome study, told Begos in Tasting the Past. "It’s really only a matter of time. If we just keep using the same genetic material, we’re doomed.”

The good news is that grape diversity could be the key to preventing rosé season from disappearing. Scientists are looking outside the noble wines and their popular cousins to old, wild, and lesser-known varieties, which "turn out to have natural disease resistance, and they've kept evolving," Begos said.

The idea is create hybrids selected for specific traits—not just pest resistance, but an ability to withstand greater heat in an era of climate change, adaptability to a wider variety of soils, and other resilient qualities.

One effort is VitisGen, a USDA-funded project involving researchers from a handful of American universities, including UC Davis, Cornell University, and the University of Minnesota. By studying the genomes of a variety of grapes, they're creating an enormous database of genetic traits. They're also experimenting with crossbreeding. Some of this genetic tweaking is decidedly old school, including pollinating grapes by hand.

Begos tells Mental Floss that they're especially interested in developing grapes that are resistant to downy mildew (Plasmopara viticola), a potential plague a la the potato famine. It can cause total crop loss if not controlled.

When it comes to selecting traits, it probably won't be flavor they'll be pulling from wild grapes, which "are really kind of terrible," Begos said. (In Tasting the Past, he quotes wine experts who describe the flavor of a fox grape as combining "animal fur and candied fruits.”) It's generally hardiness they're looking for. The concord grape in your kid's PB&J, for example, is "really tough," Begos said. Select some of its hardy genes and cross them with, say, the peppery flavor genes of the syrah grape—which the researchers have also identified—and maybe you can create a genetically resilient hybrid.

"The University of Minnesota has already had success identifying cold-hardy wine grape genes, and breeding them into new varieties that have impressed the toughest critics," Begos says, pointing to a 2015 top 10 wine list from New York Times food critic Eric Asimov. Number two on the list was made from hybrid grapes developed by UM.

You can do your part to encourage wine diversity by getting adventurous with your vino, trying a grape you've never heard of or blends from new regions. Check out organic and small wineries, which are experimenting with old cultivars and new varieties. And don't be afraid of a future with genetically tweaked grapes. We've been modifying them as long as we've been growing them. As Begos writes of these efforts, "At heart they’re unlocking flavor, disease-resistance, and growth genes that may be tens of millions of years old. To me these scientists are doing exactly what ancient Babylonians, Egyptians, and Greeks did: refining wine grapes to produce tastes we enjoy."

Why Thousands of 'Penis Fish' Washed Up on a California Beach

Kate Montana, iNaturalist // CC BY-NC 4.0
Kate Montana, iNaturalist // CC BY-NC 4.0

Nature works in mysterious ways. The latest example materialized at Drakes Beach near San Francisco, California, in early December, when visitors strolling along the shore stumbled upon what looked to be the discarded inventory of an adult novelty shop. In fact, it was thousands of Urechis caupo, a marine worm that bears more than a passing resemblance to a human penis.

The engorged pink invertebrate, which is typically 10 inches in length, is native to the Pacific coast and frequently goes by the less salacious name of “fat innkeeper worm.” Burrowing in sand, the worm produces mucus from its front end to ensnare plankton and other snacks, then pumps water to create a vacuum where the food is directed into their tunnel. Since it builds up a small nest of discarded food, other creatures like crabs will stop by to feed, hence the “innkeeper” label.

You can see the worm in "action" here:

Because the worms enjoy a reclusive life in their burrows, it’s unusual to see thousands stranded on the beach. It’s likely that a strong storm broke up the intertidal sand, decimating their homes and leaving them exposed. The event is likely to thrill otters, as they enjoy dining on the worm. So do humans: Penis fish are served both raw and cooked in Korea and China.

[h/t Live Science]

The Horrors of Anglerfish Mating

Masaki Miya et al. "Evolutionary history of anglerfishes (Teleostei: Lophiiformes): a mitogenomic perspective," BMC Evolutionary Biology 10, article number: 58 (2010), Wikimedia Commons // CC BY 2.0
Masaki Miya et al. "Evolutionary history of anglerfishes (Teleostei: Lophiiformes): a mitogenomic perspective," BMC Evolutionary Biology 10, article number: 58 (2010), Wikimedia Commons // CC BY 2.0

When you think of an anglerfish, you probably think of something like the creature above: Big mouth. Gnarly teeth. Lure bobbing from its head. Endless nightmares. 

During the 19th century, when scientists began to discover, describe, and classify anglerfish from a particular branch of the anglerfish family tree—the suborder Ceratioidei—that’s what they thought of, too. The problem was that they were only seeing half the picture. The specimens that they were working with were all female, and they had no idea where the males were or what they looked like. Researchers sometimes found some other fish that seemed to be related based on their body structure, but they lacked the fearsome maw and lure typical of ceratioids and were much smaller—sometimes only as long as 6 or 7 millimeters—and got placed into separate taxonomic groups.

It wasn’t until the 1920s—almost a full century after the first ceratioid was entered into the scientific record—that things started to become a little clearer. In 1922, Icelandic biologist Bjarni Saemundsson discovered a female ceratioid with two of these smaller fish attached to her belly by their snouts. He assumed it was a mother and her babies, but was puzzled by the arrangement.

“I can form no idea of how, or when, the larvae, or young, become attached to the mother. I cannot believe that the male fastens the egg to the female,” he wrote. “This remains a puzzle for some future researchers to solve.”

When Saemundsson kicked the problem down the road, it was Charles Tate Regan, working at the British Museum of Natural History in 1924, who picked it up. Regan also found a smaller fish attached to a female ceratioid. When he dissected it, he realized it wasn’t a different species or the female angler’s child. It was her mate.

The “missing” males had been there all along, just unrecognized and misclassified, and Regan and other scientists, like Norwegian zoologist Albert Eide Parr, soon figured out why the male ceratioids looked so different. They don’t need lures or big mouths and teeth because they don’t hunt, and they don’t hunt because they have the females. The ceratioid male, Regan wrote, is “merely an appendage of the female, and entirely dependent on her for nutrition.” In other words, a parasite.

When ceratioid males go looking for love, they follow a species-specific pheromone to a female, who will often aid their search further by flashing her bioluminescent lure. Once the male finds a suitable mate, he bites into her belly and latches on until his body fuses with hers. Their skin joins together, and so do their blood vessels, which allows the male to take all the nutrients he needs from his host/mate’s blood. The two fish essentially become one.

With his body attached to hers like this, the male doesn't have to trouble himself with things like seeing or swimming or eating like a normal fish. The body parts he doesn’t need anymore—eyes, fins, and some internal organs—atrophy, degenerate, and wither away, until he’s little more than a lump of flesh hanging from the female, taking food from her and providing sperm whenever she’s ready to spawn.

Extreme size differences between the sexes and parasitic mating aren’t found in all anglerfish. Throughout the other suborders, there are males that are free-swimming their whole lives, that can hunt on their own and that only attach to the females temporarily to reproduce before moving along. For deep-sea ceratioids that might only rarely bump into each other in the abyss, though, the weird mating ritual is a necessary adaptation to keep mates close at hand and ensure that there will always be more little anglerfish. And for us, it’s something to both marvel and cringe at, a reminder that the natural world is often as strange as any fiction we can imagine.

Naturalist William Beebe put it nicely in 1938, writing, “But to be driven by impelling odor headlong upon a mate so gigantic, in such immense and forbidding darkness, and willfully eat a hole in her soft side, to feel the gradually increasing transfusion of her blood through one’s veins, to lose everything that marked one as other than a worm, to become a brainless, senseless thing that was a fish—this is sheer fiction, beyond all belief unless we have seen the proof of it.”

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