Before revision: Encyclopedia of life sciences, 2007, John Wiley Sons, "Darwin's Finches" The Scots pine (Pinus sylvestris) has 20 different ecotypes in an area from Scotland to Siberia, all capable of interbreeding.Introduction to Ecology (1983), J.C. Emberlin, chapter 8 Ecotype distinctions can be subtle and do not always require large distances; it has been observed that two populations of the same Helix snail species separated by only a few hundred kilometers prefer not to cross-mate, i.e., they reject one another as mates.
After revision: The Scots pine (Pinus sylvestris) has 20 different ecotypes in an area from Scotland to Siberia, all capable of interbreeding.Introduction to Ecology (1983), J.C. Emberlin, chapter 8 Ecotype distinctions can be subtle and do not always require large distances; it has been observed that two populations of the same Helix snail species separated by only a few hundred kilometers prefer not to cross-mate, i.e., they reject one another as mates.