Animal behavioural genetics

Published on June 2, 2014   22 min

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0:00
I'm really honored to be doing a Henry Stewart talk. My name is Temple Grandin. I am a professor of animal science at Colorado State University. And I'm going to be discussing some of the things that we discuss in our new book, Genetics and the Behavior of Domestic Animals-- the Second Edition. Just came out really recently. One of the questions that people are always asking is, how much of animal behavior is nature-- in other words, genetics? And how much is nurture, which would be the environment.
0:35
There's an age-old question. How much of behavior is nature, and how much of behavior is nurture? And in our book, Genetics and the Behavior of Domestic Animals, myself and many other scientists have chapters to answer that question. A lot has been learned about genetics in the last 10 years. And the mechanisms are complex. The old Mendelian genetics might only explain about 25% of inheritance. What a lot of people don't realize is that only 1% of the entire double helix actually codes for proteins. That's what's called the exome. What does the rest of the genome do? When I was in graduate school student back in the '80s, they used to call it junk DNA. I never believed in junk DNA. How could so much of the genome just be junk? We know now with the Encode Project that was just published in 2013, scientists have learned that a good part of that other so-called junk DNA probably is the genes' operating system. Something has to tell the coding DNA when to code for different things, otherwise you just have big cancerous blobs. Maybe there's some junk DNA. But there's some of that definitely has got to be the genes' operating system.
1:55
Scientists have now learned that what's just in the genetic code itself is not everything that determines inheritance. There's a process of what's called epigenentics where the environment can have some effect on the expressions of genes. And there was an old scientist Lamarck who said that you could inherit acquired traits, and everybody looked at Lamarck like he was absolutely, completely crazy. Well, there's some things he's done that have proven to be right. The genome itself doesn't change. But whether or not certain code on the genome can be read has been changed. You know how the double helix looks like a double helix. Well, you can either twist it down tight like a tight spring, and then there's no way you can read it, or you can untwist it. There's also a process called methylation, which are kind of chemical locks that can lock out pieces of code. And these are factors that can determine traits that can be inherited.
2:54
Another big thing in the whole nature versus nurture controversy is how much of an animal's behavior is innate, just instinctual-- instinctual is the old-fashioned word for innate-- versus a learned behavior? Well, when I was studying animal behavior in the '60s when I was in college, BF Skinner was the biggest influence in my country. And he said, everything is stimulus response. And he wrote a famous book called the behavior of organisms. And I asked BF Skinner one time, all we need is to learn about the brain. He says, oh, we don't need to learn about the brain. We've got operant conditioning. But I never believed that. And in the genetics of behavior of domestic animals in our first chapter, we talk about instincts versus learning. And one Skinner's students, Brelands and Brelands, they wrote a paper called The Misbehavior of Organisms. And it trained animals for carnival exhibits, things like a raccoon putting a penny in the piggy bank, chicken playing the piano. And they found that instinctual behavior could override a training. Raccoons just decided they were going to wash that coin-- not just put it in the piggy bank first. They to wash it first, rub it first. Chickens found that as soon as the activity was associated with food, they just couldn't suppress scratching. Because scratching is a natural behavior they do for food. And they are definite behaviors that are fixed-action patterns that are innate. And one of those behaviors is egg-retrieval behavior in geese. The egg gets out of the nest, the goose will roll the egg back in. She'll even roll a beer can back in. And ethologists, they studied animal behavior in natural conditions. And when I was in college, I took a great classical ethology course from a scientist who was a reptile specialist. And they've got lots of innate behaviors. So at the same time that Skinner ruled psychology in America, I had this ethology professor. And reptiles, a lot of the behaviors are fixed-action patterns. Another example of a fixed-action pattern is a killing bite in a dog. Now you see, behaviors to consume food tend to be more likely to be a fixed-action pattern than behaviors to find food. Because an animal, when he's put in different environments, is going to have to be flexible or he's not going to be able to find food. For example, in bears, we've got a real problem with bears getting into garbage. Bears have learned that they can just rip the front door of a house off, and there's delicious yummies in the refrigerator. Well, most bears don't learn that behavior. It's when they learn it, it's a really, really big problem. Now both the ethologists and the Skinnerian behaviorists, they avoided the issue of what motivates behavior. I can remember when I took ethology, they discussed the hydraulic view of motivation. Which, I don't know, just seemed to me like it was kind of BS. But they didn't want to say, emotions motivated behavior?
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Animal behavioural genetics

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