Evolutionary forces in urban landscapes

Cities are comprised of “gray” and “green” spaces that may harbor non-overlapping species assemblages.  This habitat partitioning occurs on microgeographic scales (e.g. opposite sides of a street), resulting in the spatial distribution of green species resembling a photographic negative of the gray species.  The spatial genetic structure of gray and green populations should thus reflect contrasting landscape features (e.g. infrastructure / human socioeconomic variables vs. vegetation cover).  Selection pressures will also differ between these habitat classes.  I discuss the utility of this concept for explaining community structure and population genetics of rodents and invertebrates in NYC.