###

This blog is currently on hiatus owing to work commitments. Whilst I still keep an eye on the goings on at RiAus, and contribute to the work of the good folks at eLife, little will be added to this blog for the foreseeable future. Simon Says remains open for business, albeit at a reduced capacity. Thanks for stopping by, and I hope the archive of content found here will prove to be of interest.

Monday, 18 November 2013

Nikolai Vavilov: Forgotten Scientist

CENTENARY celebrations are afoot for the life and legacy of Alfred Russel Wallace, the co-discoverer of evolution by means of natural selection, who died in 1913. Many are familiar with the story of Charles Darwin, but fewer are aware of Wallace's contribution, which triggered the publication of Darwin's seminal work. Wallace is one of many poorly appreciated, and forgotten, scientists.

Another, is Nikolai Ivanovich Vavilov.

A botanist and geneticist who uncovered the geographical origins of widely grown crop plants, whose worked inspired the modern study of Crop Wild Relatives (CWRs), and whose collections were so valuable that they were guarded night and day throughout the two-year World War II Siege of Leningrad, during which at least one of his assistants starved to death; an adventurer once stranded in the Sahara, who led caravans across unmapped Afghan mountains and up the crocodile-infested Nile; a scientist whose work ensured the global population could be fed, Nikolai Vavilov died of starvation in a Soviet gulag, forgotten.

Vavilov's scientific career featured many more adventures than most scientists could dream of. Posted to Iran in 1916 to collect plants on behalf of the Russian Empire, he was arrested before even leaving his own country, charged as a 'German spy' for carrying German textbooks and diaries written in English. He was abandoned by Kyrgyz guides in the Pamir mountains in Central Asia; took a caravan of fourteen guides "and two revolvers" into Eritrea; caught malaria in Syria; caught typhus in Ethiopia; and further visited the United States; Central and South America; China, Taiwan, Japan and Korea, all in the name of collecting plants.

But why?


Vavilov collected not just plants but also seeds and, crucially, historical information. He sought the geographical and historical origins of crop plants, identifying, for example, that wheat was from Ethiopia, and apples from Kazakhstan.

Modern crops grown in agricultural areas are usually non-native, having been brought from elsewhere for larger scale cultivation. Sometimes, this can be very far from where they first evolved, which presents many problems - the crop may not be best suited to its new home, for example, or it may, unexpectedly, be invasive. At the same time, intensive breeding can restrict the genetic variation of a plant, because it has been honed and refined over many generations to be the best at one specific thing, like a specific colour, or texture, or harvest yield. That's fine while environmental conditions are steady, but you only have to stumble across a new disease, brought in by a new crop or pest, and the low genetic variation means that the entire crop can be wiped out in one go.

Wild wheat from the Erebuni Reserve, Armenia
Source, Owner: WOWARMENIA
Understanding the original plants, and the conditions that the plant evolved in, provides a genetic portfolio to fall back on when this happens. Vavilov also collected seeds, as a record of genetic diversity, but also as a fall-back should plants go extinct in the wild. It was his extensive seed collection, exceeding 175,000 different items as of 1969, that was guarded to the death throughout the Siege of Leningrad, despite being completely edible.

Nowadays there are several seed banks around the world. These are so important that they are housed in bomb-proof - sometimes nuclear bomb-proof - vaults.

Here's one reason why this is important. Sunflower seeds from Vavilov's collection, taken from Texas in 1932, were selectively bred by researchers in the Soviet Union independently of sunflower oil production in the United States. By 1962, they had a stable crop with much higher sunflower seed-oil content, and it was re-introduced to Texas in 1972. Agriculture had taken the crop in one evolutionary direction, yet it was improved by going back to the source. As the global climate changes, source plants could be used to introduce tolerances to drought, disease and salt to cultivated varieties, ensuring world food production can be maintained.

Work continues today to understand the living ancestors of crop plants, the CWRs. Focus has switched, however, to preserve CWRs in situ - that is, where they naturally grow, rather than keeping their seeds or cuttings in a vault. It was Vavilov who first realised the importance of CWRs for improving crops - and for solving the food crisis across the Soviet Union.

Vavilov was the archetypal esteemed academic, respected for his knowledge and dedication. That is, until he got on the wrong side of politics. He had trained a radical apprentice, Trofim Lysenko, whose theories were unfounded in science but which Vavilov was always prepared to entertain by means of experiment. But Lysenko falsified data and used biological terms mixed with Marxist-Leninist propaganda to further his own cause, rising to be Stalin's scientist of choice. This proved a dangerous turn of events for anybody who actually cared about science - such as Vavilov, whose contributions were now ignored.

In 1929, the Communist Party model enforced collectivization of farms across the Union. The new, intensive, collectivized farms, or kolkhozes, replaced the ancestral, traditional nomadic lifestyle that dominated the Central Asian steppe, a culture that Stalin sought to destroy. The steppe could not support such intensive farming - as Vavilov had warned - and the plan failed, plunging thousands into starvation. On the back of this, Lysenko continued to rise, suggesting ever more grandiose, ridiculous and unfounded solutions to the problem, yet laced with sycophantic praise of Stalin and deliberate digs at genuine scientists. Stalin subsequently promoted Lysenko's ideas (and everybody, scared witless, cheered and hurrahed in due course), and destroyed the work of Vavilov. At conferences, Stalin would not deign to listen to Vavilov's findings, leaving the room as he began to speak.

In 1940, Vavilov was given surprise permission to visit the Ukraine on a field trip. It was a trap. He was arrested and imprisoned on falsified charges.
"He was placed in solitary confinement for six months, during which time accomplices were arrested, including one dangerous subversive who was the country's leading authority on the pea, the runner bean and the lentil."
Hurried by the advance of Nazi Germany on the Soviet Union, the trial was rushed. Vavilov was sentenced to death by firing squad.

From this he was spared, in a sense, by failing health. On 26 January, 1943, weakened by scurvy, a final bout of dysentery took the remaining morsels of life from him, and he passed away into obscurity.

It's not a happy story. But the man was brilliant, and he deserves to be remembered that way.

As we celebrate the 100th anniversary of the life of Alfred Russel Wallace, may we also celebrate the 70th anniversary of the life of Nikolai Ivanovich Vavilov - explorer, pioneer, victim.


Sources

Robbins, C. In Search of Kazakhstan (Profile Books, 2008)
Pringle, P. The Murder of Nikolai Vavilov (JR Books, 2009)

Nikolai Ivanovich Vavilov - Explorer and Plant Collector

Maxted, N. & Kell, S. Establishment of a global network for the in situ conservation of crop wild relatives: status and needs (European crop wild relative diversity assessment and conservation (PGR) forum)
Burger, J. C., Chapman, M. A. & Burke, J. M. Molecular insights into the evolution of crop plants Am. J. Bot. 95, 113-122 (2008)

No comments:

Post a Comment