This is a story about tofu, but it begins with a death threat. Or, rather, many death threats.

Late last year, Harvard entomologist Piotr Naskrecki's inbox was filled with them. He was called a "HORRIBLE person" who would "destroy the earth." "F&*K you, a$$hole," another thoughtfully self-censoring correspondent wrote.

How does a scientist and photographer studying katydids, a cricket-like insect, become targeted by the vociferous, quick-to-anger internet community? Naskrecki, who several years ago was conducting his katydid research in the rainforests of Guyana, also encountered many other species of insects while there. Last October, he posted a photo on his blog of one such creature, the Goliath birdeater, a huge, furry, nightmare-inspiring arachnid. Naskrecki described the specimen he found as weighing about as much as a young puppy, and also mentioned that one of the spiders had been killed for preservation in Harvard's Museum of Comparative Zoology.

Cue the hate mail. Readers, apparently ignorant of the fact that scientific preservation of flora and fauna is an essential part of understanding and therefore protecting plants and animals, flooded the blog's comments section with vitriol, accusing him of killing off rare rainforest species, and, yes, even threatened to kill him. But in a response blog post, Naskrecki pointed out the ridiculousness of getting angry at conservation-minded scientists who may have to kill a few animals along the way when it reality, what he called "involuntary bioslaughter" occurs every day.

"That tofu that you eat because meat is murder," he wrote. "It probably comes from Brazil, where massive soy plantations stretching from one horizon to another have replaced its once thriving rainforest and led to the disappearance of thousands of species."

And he's right. Behind the US, Brazil is the world's second-largest grower of soybeans, which make their way into everything from oil to prepared foods to animal feed. In the 2014-2015 season, the USDA predicts that the country will devote a record 31.5 million hectares, or about 78 million acres, to the crop, and that it will harvest a record 95.5 million tons of the legumes.

Making room for soy plantations means clearing land, and in tropical Brazil, clearing land often means clearing rainforests. The country remains one of the most biodiverse in the world, but that's rapidly changing. Soy cultivation is moving into the Amazon, the world's largest rainforest, where in coming years 38 species of mammals, birds, and amphibians are predicted to go extinct. The Amazon is also a major carbon sink: its estimated 80,000 species of plants absorb about 2.2 billion tons of carbon dioxide per year and play a crucial role in offsetting global warming by lowering the planet's levels of greenhouse gases. As plants and soil there are dug up to be replaced with soy crops, that stored carbon is released back into the atmosphere, speeding global warming.

And it's not just rainforests that are threatened by Brazil's ever-growing soy production. The Cerrado, the vast savannah region that covers one fourth of the country, is also one of the most biodiverse ecosystems on the planet. But over the past decade, it has been particularly vulnerable, not only to soy plantations but also to cattle-raising operations; between 2002 and 2008, the Cerrado lost an average of 14,000 square kilometers each year. Those numbers mean huge losses to the habitat's 32 endangered animal species, as well as to native plant species, widely depended on by locals as food or medicine, and almost half of which are found nowhere else on earth.

When it comes to soy in the average diet, it's true that the meat industry is a much bigger driver of soy production than is demand for soy products such as tofu. The majority of the soy grown in the world ends up in livestock feed, to be given to poultry, pork, cattle, and farmed fish, or as soybean oil. But about six percent of soy does go directly into all those meat- and dairy-free foods we like to feel so virtuous about eating: soy milk, tofu, and the whole huge range of fake meat products.