tailieunhanh - Freeland - Molecular Ecology (Wiley, 2005) - Chapter 2

2 Molecular Markers in Ecology Understanding Molecular Markers In Chapter 1 we started to look at the extraordinary wealth of genetic information that is present in every individual, and to explore how some of this information can be accessed and used in ecological studies. | 2 Molecular Markers in Ecology Understanding Molecular Markers In Chapter 1 we started to look at the extraordinary wealth of genetic information that is present in every individual and to explore how some of this information can be accessed and used in ecological studies. We will build on this foundation by looking in more detail at some of the properties of the genetic markers that are used in molecular ecology. We will start with an overview of the different genomes because the use and interpretation of all markers will be influenced by the way in which they are inherited. The second half of the chapter will be an overview of those molecular markers that are most commonly used in ecology. After reading this chapter you should understand enough about different molecular markers to suggest which would be applied most appropriately to general research questions. Modes of Inheritance Genetic material is transmitted from parents to offspring in a predictable manner and this is why molecular markers allow us to infer the genetic relationships of individuals. This does not simply mean that we can use genetic data to determine whether two individuals are siblings or first-cousins. In molecular ecology the calculation of genetic relationships often takes into account the transmission of particular alleles through hundreds thousands or even millions of generations. In later chapters we will look at some of the ways in which both recent and historical genealogical relationships can be unravelled but first we must understand how different genomic regions are passed down from one generation to the next. Not all DNA is inherited in the same way and understanding different modes of inheritance is crucial before we can predict how different regions of DNA might behave under various ecological and evolutionary scenarios. Molecular Ecology Joanna Freeland 2005 John Wiley Sons Ltd. 32 MOLECULAR MARKERS IN ECOLOGY Nuclear versus organelle The offspring of sexually reproducing .