Biology Reference
In-Depth Information
Part I.
Basic Concepts of Alien Invasion
and Evolution
In this introductory series of chapters, we outline the basic issues of evo-
lutionary biology of alien species and consider basic aspects of dispersal
capabilities and genetic variability that are central to the study of evolu-
tionary change by aliens.
In chapter 1, we begin our examination by reviewing the magnitude
and economic impact of worldwide introduction of plants, animals, and
microorganisms to new geographic regions. Patterns of rapid evolution
associated with these introductions are then presented, and their general
significance is described.The major evolutionary issues that will be exam-
ined in succeeding chapters are then outlined.
Chapter 2 begins our examination of specific evolutionary issues by
considering the selective pressures that act on mechanisms of dispersal by
species poised to invade new regions or exposed to the agents of long-
distance transport that modern human technology has created.The adap-
tations and evolutionary responses that enable the individuals that reach
new regions to become established and spread are also discussed.
In chapter 3, we consider the patterns of genetic variability that species
bring with them to new regions. First, we review the most important
techniques of assessing genetic variability in populations of species, both
in their native source populations and in newly established alien popula-
tions. We then consider how the processes of introduction and establish-
ment tend to influence the genetic structure of founder populations.
Finally, in chapter 4, we examine how analysis of the genetic compo-
sition of populations of alien species in their native regions and regions of
introduction can reveal precise source regions and invasion routes. In
1
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