Do have a cow, man, as both man and beast are squeezing out other species
Q. What’s the story behind the line: “Birds of a feather can rob together?”
A. As David G. Myers and C. Nathan Dewall tell it in “Exploring Psychology,” in 2009, thieves broke into a Berlin store and stole jewelry worth $6.9 million. Left behind by one of the thieves was a link to his genetic signature—a drop of sweat. But when police analyzed the DNA, they found two matches from identical twin brothers. “The court ruled that ‘at least one of the brothers took part in the crime, but it has not been possible to determine which one.’” Apparently, some birds of a feather can rob together with impunity.
Q. Which are we — Planet of the Cows, or Planet of Homo sapiens? Stay tuned for a rather weighty discussion.
A. Bear in mind we can estimate both cattle zoomass and human biomass with a fair degree of accuracy, reports Vaclav Smil in “IEEE Spectrum” magazine. In 2015, the Food and Agricultural Organization of the United Nations put the global cattle count at about 1.5 billion head, but that was before necessary adjustments for age and sex distribution, yielding a total live cattle zoomass of some 600 million metric tons. Similar adjustment must be made for humanity’s biomass, taking into account the age and body weights of populations. For example, “low-income countries have much higher shares of children than affluent nations (in 2015, about 40% in Africa compared to about 15% in Europe). At the same time, the rates of overweight and obese people range from negligible (in Africa) to 70% of the adult population (United States).” Given a total of 7.4 billion people, the global anthropomass was about 370 million metric tons. So, the numbers say Planet of the Cows it is.
But that’s not the complete picture. Taken together, both cows and humans occupy much of the available land, leaving too little space for the multitude of other species. Concludes Smil: “No wonder we are in the midst of mass-scale species extinction, with no readily acceptable and effective relief in sight. By 2050 there will be 9 billion people and, most likely, 2 billion cattle, together augmenting their already crushing dominance of Earth.”
Q. We’ve all heard that humans have a poor sense of smell compared to other mammals, such as dogs and cats. Yet recent research labels this “a 19th-century myth.” Why?
A. Rutgers University behavioral neuroscientist John McGann in “Science” magazine argues that the poor reputation of the human sense of smell is undeserved, based on philosophical biases and errors of interpretation. In fact, there’s a remarkable consistency in the number of neurons in the olfactory bulbs of all mammals, from mice to humans to elephants. Furthermore, the results of odor discrimination tests depend critically on what is being smelled. “Dogs may be better than humans at discriminating the urines on a fire hydrant and humans may be better than dogs at discriminating the odors of fine wine, but few such comparisons have actual experimental support.” On the other hand, experiments have shown that humans are 1000 times more sensitive to certain odorants than are mice or monkeys and we can discriminate between more than 1 trillion compounds.
As McGann explains, “Each person produces a distinct odor… that permits the discrimination of kin from non-kin…. The contents of this ‘body odor cocktail’ can drive mate and food choice, as well as communicating information about anxiety and aggression… Indeed, our sense of smell is much more important than we think.”