By Andrew Sensenig
My wife has the book ?Animals Makes Us Human? in her collection, so I started reading it last month. Author Temple Grandin is an animal welfare specialist and studies ways to improve livestock facilities to reduce stress on confined animals.
Cattle can be calmed by curved chutes with high walls on the way to slaughter. During their growing phase, smart animals, such as pigs, should be provided with enrichment such as straw or balls or hoses hanging from the ceiling.
We don?t have an objective measure of animal happiness, and possibly cannot by definition, but many attempts have been made.
Such an attempt is outlined in the first chapter, and captured well the excitement of science. A previous researcher had placed rats in cages?one cage with toys, the other without toys. Rats with toys grew bigger brains in the area of the brain dedicated to vision (the visual cortex).
This is not surprising. Rats use their eyes quite a bit to explore their environment, and stimulated rats grow bigger brains.
Grandin designed a similar experiment with pigs. She found something surprising. The pigs without the toys grew a bigger brain in the area dedicated to processing touch (somatosensory cortex). In a sense, the pattern was opposite to that seen in rat brains. Grandin told the rat researcher her results. He said, ?Oh, sh*t!?
Grandin studied the pig behavior further, and figured out that bored pigs spent a huge amount of time pushing and probing any object they could find with their snouts. Even at night, when pigs with toys were pleasantly sleeping, the bored pigs were pushing on cage bars, other pigs and their water dispensing nipple.
Grandin proposed that, thanks to the lack of diverse stimulation, the neurons associated with the snout expanded in the brain of the pigs to compensate for the lack of input.
An ?oh sh*t? moment can actually be a wonderful time in the work of a scientist. The exciting nature of science is that previous ideas can be subject to rejection. Scientists often seek to generalize their ideas to all other cases or places in the universe.
For example, the great scientist of physics, Isaac Newton, in 1687 proposed that his three laws of motion applied to things even as far away as orbs outside our own sphere.
Gradually, folks accepted that indeed his three laws of motion did apply to all places and times in the universe, and for most practical purposes, this is still the case.
This was such a radical shift in the way that the universe was viewed, that it is now termed a ?Scientific Revolution.?
It is harder to make generalizations in biology. Something about the emergent properties of life defy the formulation of relatively simple ?laws? such as proliferate in physics. But biology is full of ?theories.?
In the sciences, a theory is not an idea that appeared in someone?s head a moment ago, but is instead a grand idea supported by diverse lines of evidence. Theories in the biological sciences include Cell Theory, Organic Evolution, and Germ Theory of Disease.
Cell Theory is the idea that all organisms are composed of small units of fluid bags, most of which are so small that a microscope is necessary to see them.
Organic Evolution is the idea that organisms are descended from other organisms, and through natural selection and other forces, gradually assume forms and lifestyles different than their ancestors.
Germ Theory of Disease is that invisible particles can spread from one creature to another, grow and then cause disease.
All scientific ideas are subject to rejection or caveats as time marches on. This is disconcerting and humbling.
I want to know that my view of the universe is correct, but human perspective is limited. As a scientist, I am always skeptical of new ideas, but at the same time I look forward to the next scientific revolution, where what I think I know may be turned upside-down.
Andrew Sensenig is assistant professor of biology at Tabor College. You can email him at andrew.tabor.edu.