An international group of plant pathologists has solved a historical mystery behind Ireland's Great Famine.
Sure, scientists have known for a while that a funguslike organism called Phytophthora infestans was responsible for the potato blight that plagued Ireland starting in the 1840s. But there are many different strains of the pathogen that cause the disease, and scientists have finally discovered the one that triggered the Great Famine.
And although so many Irish emigrated to the U.S. to escape the devastation, little did they know they were only getting closer to the source of the pathogen in the Americas.
A team of researchers from the U.K., Germany and the U.S. sequenced the genomes of some herbarium samples — dried plants preserved by botanical gardens and museums. They compared the pathogens in 11 of these potato samples from more than 100 years ago with 15 modern strains and found the one responsible for Ireland's devastating blight. The culprit's name? They dubbed it HERB-1.
This uprooted the previous theory that another strain, called US-1, was behind the blight. But the two are closely related, says Sophien Kamoun, a co-author of the study, which appears in the journal eLife. With this information, he and the other scientists deduced a possible timeline for Phytophthora infestans.
Everything began in Mexico's Toluca Valley, the center of the pathogen's diversity. "The Spanish introduced Europeans to the South American staple crop potato shortly after their conquest of the New World," the authors write, "but for three centuries Europe stayed free of P. infestans."
They think that it wasn't until the start of the 19th century that a strain of the pathogen left Mexico. Wherever it ended up — the researchers suspect farther north in North America — it then separated into HERB-1 and US-1, and each strain set off on to take over the world, one potato at a time.
By the summer of 1845, HERB-1 had made it to Europe and spread quickly across the continent. Because of Ireland's high dependence on potatoes and its fragile socioeconomic status, losing much of the crop to the blight was catastrophic. A million Irish died and another million left the island before the famine lifted in 1852.
In the early 20th century, people began breeding potatoes that would be more resistant to pathogens. "We have some data from the genetics that suggests that HERB-1 wouldn't have been able to cope with those resistance genes," Kamoun says. "Of course, we can never really know for sure, but it looks like HERB-1 is most likely extinct at this point." Even the heartier US-1, which dominated the globe for 150 years and is still around today, was overshadowed by more aggressive strains in the 1970s.
But the scientists weren't merely sleuthing for the sake of history. Though the pathogen behind the Irish potato famine is no longer a threat, related strains, they say, are still a menace.
"Potato blight is still a huge problem worldwide," Kamoun says. "[It's] the third most important food crop in the world, and potato blight is the major constraint for growing potatoes." One 2012 estimate says the amount of potatoes lost each year to blight would be sufficient to feed at least 80 million people — and perhaps hundreds of millions more.
So plenty of scientists are trying to breed new potato varieties either through classical breeding or through genetic modification, but they're up against the "amazingly adaptable" Phytophthora infestans. "Understanding the pathogen dynamics and how the pathogen has evolved through time is really important for helping us predict future changes in pathogen populations," Kamoun says.
And to him, the millions of herbaria stored in museums are hidden treasures just waiting for researchers to find. "We can go back and not just look at the leaves or identify the species by looking at the shape of the flowers... we can actually get to the DNA," he says. "This is a great example of how we can use all those treasures in museums and use the latest technology to exploit information that's in those museums."
In Orlando, Fla., early Wednesday "an FBI agent was involved in a deadly shooting connected to the Boston Marathon bombing case," NBC News is reporting. A man who was being questioned by the agent is dead. NPR's Dina Temple-Raston and Carrie Johnson have also confirmed the news.
Just how firm the man's alleged connection to the marathon case is, though, remains unclear.
The dead man has been identified by NBC, the Orlando Sentinel and Orlando's WESH-TV as 27-year-old Ibragim Todashev. Another man, Khusn Taramiv, was the first to connect Todashev's death to the investigation into the Aprill 15 bombings in Boston. The Sentinel says that:
"Taramiv told several television outlets his friend was being investigated as part of the Boston bombings and Todashev knew bombing suspect Tamerlan Tsarnaev because both were mixed martial-arts fighters."
A source with knowledge of what happened tells our colleagues that the FBI agent was conducting an interview related to the bombings investigation when the individual being questioning became violent. Other law enforcement personnel were there as well. During the confrontation, the source tells the NPR correspondents, "the individual was killed."
So far, according to the Sentinel, FBI spokesman Dave Couvertier has only officially confirmed that "the agent encountered the suspect while conducting official duties. ... We are still gathering facts involving the shooting incident."
Taramiv, the friend of the suspect killed in Orlando, has told WESH-TV that "the FBI) took me and my friend, (Ibragim Todashev). They were talking to us, both of us, right? And they said they need him for a little more, for a couple more hours, and I left, and they told me they're going to bring him back. They never brought him back."
Taramiv also said that Todashev, like Boston suspect Tsarnaev, was an ethnic Chechen and that the two men spoke to each other by telephone a month or so before the marathon bombings. "He wasn't radical," Taramiv said of his friend, Todashev.
Tsarnaev, 26, died on April 19 from injuries he sustained during a gun battle with police in Watertown, Mass. The other suspect in the bombings, his 19-yer-old brother Dzhokhar, was captured on April 19. He has been charged with using a weapon of mass destruction.
Jason Bentley, KCRW Music Director
Yo La Tengo has been able to stick together and make music on its own terms for more than 20 years; in today's climate, that's as rare as it is impressive. In an interview for KCRW, singer Ira Kaplan said the band likes to keep its process in the air and of the moment. On the occasion of Yo La Tengo's return to Morning Becomes Eclectic, Kaplan and his colleagues continued to bend the rules, as they performed their songs in totally new arrangements, alongside new covers and a few samples from their most recent album, Fade.
Watch Yo La Tengo perform a KCRW favorite called "Two Trains" on this page, then watch Yo La Tengo's entire Morning Becomes Eclectic session at KCRW.com.
The next mayor of Los Angeles will be City Councilman Eric Garcetti.
In a race in which the two top contenders were both Democrats, the 42-year-old Garcetti has opened a 7- to 8-percentage-point lead over City Controller Wendy Greuel as Tuesday's votes are being counted.
"Thank you Los Angeles — the hard work begins but I am honored to lead this city for the next four years. Let's make this a great city again."
As Morning Edition and NPR Political Junkie Ken Rudin have explained, the race to succeed outgoing Mayor Antonio Villaraigosa attracted little attention in the city. According to Ken, both Garcetti and Greuel were "earnest, sincere, non-ideological candidates" and neither seemed certain about "how to handle the [city's] growing deficit, let alone tell voters which way they intend to take the city."
Garcetti has been on the city council since 2001. He is the son of former Los Angeles County District Attorney Gil Garcetti, who rose to national fame during the 1995 criminal trial of O.J. Simpson.