ABSTRACT
The computer program NEWGARDEN is designed to help conservation or evolutionary biologists, as well as students, explore how the number of founders, the geometry of the initial spatial positioning of the founders, and life history characteristics of a given species interact to infl uence the growth rates of colonizing plant populations and their retention of genetic diversity. In a given NEWGARDEN analysis trial, the user specifi es the initial conditions for population establishment and continuing development, and by changing these specifi cations in alternate comparative trials, the user can explore the effects of varying one or a few conditions or factors in combination on population growth and genetic diversity over generations. The NEWGARDEN populations that develop according to the specifi ed input conditions are simulated populations for which each new generation is created as a result of virtual matings between individuals as brought about by those user-defi ned input specifi cations. In other words, the generations develop not on the basis of general theoretical modeling formulas, but rather via virtual matings and offspring production controlled by user-defi ned parameters and resulting population growth phenomena described below. The program is designed to be easy to use so that it can be employed, with a little practice, by a wide range of practitioners, including students. To make the principles involved more accessible to a wide audience, below we review relevant basic concepts that practicing biologists steeped in population genetics can skip over. Students new to these concepts would benefi t from consulting texts offering more extensive treatments (e.g., Hartl and Clark 2007; Hedrick 2010).
