7. Behavioral Genetics II | Summary and Q&A

Summary

This video discusses the field of behavior genetics and how it explores the relationship between genes and behavior. It explains how researchers use different approaches to identify genetic variations that are associated with certain behaviors or traits. The video also introduces the concept of heritability and clarifies that it does not measure how much genes determine the average level of a trait, but rather how much genes influence the degree of variability around that average.

Questions & Answers

Q: What interesting traits have been discovered in Siberian foxes and metro dogs?

Siberian foxes bred for tameness resulted in physical traits resembling puppies after 30 generations, showing that evolution can occur rapidly. Metro dogs living in the Moscow subway system have been selected for abilities to scrounge and are often scared of humans, leading to physical changes resembling wolves after 30 generations.

Q: What is the relationship between behavior genetics and evolutionary change driven by actual mutations?

Behavior genetics focuses on patterns of behavior that are associated with relatedness, rather than constructing an evolutionary story based on actual mutations at the molecular level. It looks for behavioral traits that go along with relatedness, but it does not explain the molecular changes driving the evolutionary process.

Q: What are some of the classic approaches used in behavior genetics research?

Classic approaches in behavior genetics research include studying monozygotic (identical) versus dizygotic (fraternal) twins, studying adopted individuals, and studying identical twins separated at birth and then reunited. These approaches aim to eliminate the influence of different environments and explore the impact of genetic relatedness on certain traits.

Q: How does the field of behavior genetics study the effects of prenatal environment on behavior?

Behavior genetics research examines the effects of prenatal environment on behavior, particularly through the study of fetal origins of adult disease. Early events during fetal development can have lifelong consequences and even impact future generations. This includes understanding the mechanisms of epigenetics and how environmental factors can affect gene expression.

Q: What are some challenges in behavior genetics research?

One major challenge in behavior genetics research is the influence of non-genetic factors, such as different environments, on observed traits. Adoption placements may not be random, making it difficult to separate genetic and environmental influences. Additionally, there are complexities in studying prenatal and early environmental effects, as well as the role of chance in genetic variability.

Q: How has the field of behavior genetics integrated molecular biology techniques?

In the past few decades, behavior genetics has integrated molecular biology techniques to find specific genes associated with behavior. Researchers use techniques like genetic markers, gene sequencing, microarrays, and quantitative trait loci to identify genetic differences related to behavioral traits. These approaches allow for the exploration of single genes, multiple genes, and gene networks.

Q: How do researchers use genetic variations to study the relationship between genes and behavior in humans?

Researchers start by studying genetic variations related to specific behaviors in animals. Once they understand the mechanisms and effects of specific genes in animal models, they look for similar genetic variations in humans. By comparing different variants of genes and their effects on behavior in humans, researchers can determine the influence of genes on certain traits.

Q: What is the role of chance in behavior genetics?

Chance plays a significant role in behavior genetics. Random events, like mitochondrial distribution during cell splitting and the distribution of different types of transcription factors, can lead to variability in traits. Additionally, chance is involved in the distribution of transposable genes during neural stem cell division. Chance contributes to the complexity and unpredictability of behavior genetics research.

Q: What does heritability measure in behavior genetics?

Heritability measures the extent to which genetic factors contribute to the degree of variability in a trait, not the average level of the trait. It does not indicate the importance of genes in determining the average level of a trait, but rather the influence of genes on the variation of that trait within a population.

Q: What is the common misconception about heritability in behavior genetics?

The common misconception about heritability is that it measures how much genes determine the average level of a trait. This is incorrect. Heritability measures the contribution of genes to the variation in a trait within a population, not the average level of the trait itself.

Takeaways

Behavior genetics research explores the relationship between genes and behavior by studying genetic variations associated with certain traits. Different approaches, such as studying animal models and investigating genetic markers, are used to identify genes related to behavior. Chance plays a role in genetic variability, and heritability measures the contribution of genes to the degree of variation in a trait, not the average level of the trait. It is important to understand the true meaning of heritability and how genes influence the variability of traits within a population.