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There are strong genetic determinants of behavior in most species. Gene manipulations such as mutations and knockouts show that a single gene can play a large role in the development and expression of a behavior. Although most behaviors are controlled by multiple genes, those genes frequently function in signaling cascades, so a single gene modification can influence even a complex behavior controlled by many genes.
learning outcomes
You should be able to:
Give examples of a single gene influencing a behavior.
Describe different kinds of evidence supporting the claim that single genes can influence behavior.
Explain the evolutionary benefit of a gene expression cascade that influences behavior.
A method has recently been developed to increase the expression of oxytocin and vasopressin genes in montane voles. What difference might that treatment make in the behavior of these animals? If the expected result is not seen, what could be the reason?
If the expression of vasopressin and oxytocin genes is increased in montane voles, the voles should be more likely to form pair bonds, and both males and females should exhibit increased parental care. If that result is not observed, it could be due to the lack of receptors in the right brain areas of the montane vole.
If you interbred two individuals from separate populations that bred true for a trait that differed between the two, and all of the offspring resembled one of the parents, what would you conclude about the genetic basis for that behavior?
You would conclude that the trait is likely controlled by a single gene with a dominant and a recessive allele.
What could be an evolutionary reason for a species-
The evolutionary advantages of having a species-
How can the genetic cascades that underlie complex behaviors be programmed to respond selectively to specific sets of stimuli? How can their expression be limited to appropriate times in an animal’s life? The answers to these questions can be found by studying how behaviors develop over the life span.