Altruism Circadian rhythm Neanderthal Pheromone

Measuring Genetic Diversity in Human Populations Successful adaptation is defined by: a. evolving new traits b. producing many offspring c. leaving more offspring than others d. moving to a new location

Name three genes whose mutations lead to an altered behavioral phenotype. Briefly describe the normal function of the mutated gene as well as the altered phenotype.

The training of animals usually involves ______________ ___________ . imprinting classical conditioning operant conditioning cognitive learning

If a test were available that could tell you whether you were likely to develop a disorder such as schizophrenia later in life, would you take the test? Why or why not? Rachel asked to see a genetic counselor because she was concerned about developing schizophrenia. Her mother and maternal grandmother both had schizophrenia and were institutionalized for most of their adult lives. Rachels three maternal aunts are all in their 60s and have not shown any signs of this disease. Rachels father is alive and healthy, and his family history does not suggest any behavioral or genetic conditions. The genetic counselor discussed the multifactorial nature of schizophrenia and explained that many candidate genes have been identified that may be mutated in individuals with the condition. However, a genetic test is not available for presymptomatic testing. The counselor explained that based on Rachels family history and her relatedness to individuals who have schizophrenia, her risk of developing it is approximately 13%. If an altered gene is in the family and her mother carries the gene, Rachel has a 50% chance of inheriting it.

As outlined in this chapter, sex can be defined at several levels: chromosomal, gonadal, and phenotypic. To this we can add psychological sex, the sex one believes themselves to be. Determining someones sex is a complex issue that is often difficult to resolve, as the case of Bruce Reimer (see Section 7.1) illustrates. In spite of the complexity surrounding this issue, the International Olympic Committee (IOC) and the International Association of Athletics Federations (IAFF) still use sex testing on female athletes to determine whether they can compete in athletic events as females. This has led to serious personal, social, and legal issues, and the practice has been widely condemned and widely defended. Lets examine two such cases here. An Indian athlete, Santhi Soundarajan, finished second in the 800-meter run at the Asian Games in Doha, Qatar, in 2006. After the race, she was asked to take a sex test. According to press reports, the tests showed that she appeared to have abnormal chromosomes. An official stated that she had more Y chromosomes than allowed. As a result, she was stripped of her medal, banned from further competition by the Indian Olympic Association, and shunned by her local community. Before the race in Doha, Santhi had competed in 8 international competitions and won 12 medals. Sometime after this incident, she attempted suicide. She now runs a training school for athletes in Tamil Nadu, India. Although the number and types of tests done on Santhi have not been revealed, such tests usually involve examination of the external genitals, a chromosome analysis, and measurement of hormone levels. Suppose you were on the committee deciding whether Santhi could compete as a female. Consider each of the following hypothetical tests one at a time and base your conclusions only on the results of that test. The results of a physical examination show she has female genitals. On this basis, would you allow her to keep her medal and compete as a female in future races? Suppose the results of a chromosomal analysis shows that she has an XY chromosome set and is chromosomally male. Would you allow her to keep her medal and compete as a female? Lastly, suppose a test for hormone levels shows that she has levels of the male sex hormone testosterone that are higher than average for females but at least 10 times lower than the average for males. Would you allow her to keep her medal and compete in future races as a female? Now, put the results of all three tests together, and consider them as a whole. What are your conclusions? Now, lets consider the case of a South African runner, Caster Semenya, who won the 800-meter run at the World Championships held in Berlin, Germany, in 2009. After the race, she was asked to undergo sex testing. The IAAF stated that the tests were requested to ascertain whether she had a rare medical condition that gave her an unfair physical advantage. The nature of the tests and their results were not released, but press reports indicate that she did not have ovaries or a uterus, and had testosterone levels intermediate between the averages for males and females. In the end, the IAAF agreed to keep the results of her tests confidential, and Caster was allowed to keep her medal and return to international competition in 2010. In both cases, what the IAAF considers the threshold for determining who can compete as a female has not been stated. Would you recommend that testing of female athletes be continued to ensure that males do not compete as females? Or should all such testing be banned?

True or false? Some humans are genetically modified.