PART TYPE DRAIN. “In other words, in hierarchical transitions, there is a drain on numbers of part types at the lower level.”
http://www.bioone.org/doi/abs/10.1554/0014-3820(2002)056%5B0441:ACDOCI%5D2.0.CO%3B2
PART TYPE DRAIN. “In other words, in hierarchical transitions, there is a drain on numbers of part types at the lower level.”
http://www.bioone.org/doi/abs/10.1554/0014-3820(2002)056%5B0441:ACDOCI%5D2.0.CO%3B2