Exam 9: Evolution at Multiple Loci: Quantitative Genetics

Traits that are conditioned by multiple loci and form continuously variable phenotypes that are conditioned by both the genotypes and environmental influences are most appropriately termed ________.

Heritability measures ________.

Three distinct modes of selection have been proposed and studied in natural populations.Each mode is different in its effects on the mean value and distribution of phenotypes.Compare and contrast each of these three modes.

Explain,using examples/equations,the similarities and differences between broad-sense and narrow-sense heritability estimates.

The authors of your textbook described two ways in which the strength of selection can be measured.What are these two ways?

When Clausen and colleagues grew genetically identical individuals of the yarrow plant at different elevations,the results are shown in the accompanying figure.This observation verifies that ________.

The experimental work of Edward East in 1916,shown in the accompanying figure,confirmed that ________.

Estimating heritability using twin studies has been useful for certain human phenotypes,such as general cognitive abilities.Explain the logic behind this,and how such studies are performed.

Determining the best-fit line for a data set by utilizing the least-squares linear regression,the slope of the resulting line represents a useful estimate known as the ________,[two words] for which we use the symbol h².

Suppose we consider the figures below.If Figure A represents a measurable trait in a population at time 0,and Figure B represents the same trait some generations later,we can conclude that the type of selection called ________ selection has been at work. Figure A Figure B