Systematic Botany and Mycology, University of Munich, Menzinger Street 67, 80638 Munich, Germany.
Philos Trans R Soc Lond B Biol Sci. 2010 Feb 12;365(1539):423-35. doi: 10.1098/rstb.2009.0229.
The interactions between bees that depend on floral oil for their larvae and flowers that offer oil involve an intricate mix of obligate and facultative mutualisms. Using recent phylogenies, new data on oil-offering Cucurbitaceae, and molecular-dating, we ask when and how often oil-offering flowers and oil-foraging bees evolved, and how frequently these traits were lost in the cause of evolution. Local phylogenies and an angiosperm-wide tree show that oil flowers evolved at least 28 times and that floral oil was lost at least 36-40 times. The oldest oil flower systems evolved shortly after the K/T boundary independently in American Malpighiaceae, tropical African Cucurbitaceae and Laurasian Lysimachia (Myrsinaceae); the ages of the South African oil flower/oil bee systems are less clear. Youngest oil flower clades include Calceolaria (Calceolariaceae), Iridaceae, Krameria (Krameriaceae) and numerous Orchidaceae, many just a few million years old. In bees, oil foraging evolved minimally seven times and dates back to at least 56 Ma (Ctenoplectra) and 53 Ma (Macropis). The co-occurrence of older and younger oil-offering clades in three of the four geographical regions (but not the Holarctic) implies that oil-foraging bees acquired additional oil hosts over evolutionary time. Such niche-broadening probably started with exploratory visits to flowers resembling oil hosts in scent or colour, as suggested by several cases of Muellerian or Batesian mimicry involving oil flowers.
依赖幼虫油脂的蜜蜂与提供油脂的花朵之间的相互作用涉及到强制性和兼性互利共生的复杂混合。利用最近的系统发育、有关提供油脂的葫芦科植物的新数据和分子年代学，我们询问提供油脂的花朵和采油蜜蜂的进化时间和频率，以及这些特征在进化过程中丢失的频率。局部系统发育和被子植物的全系统发育树表明，油花至少进化了 28 次，而花油至少丢失了 36-40 次。最古老的油脂花系统在白垩纪-第三纪边界之后独立地在美洲 Malpighiaceae、热带非洲 Cucurbitaceae 和 Laurasian Lysimachia（木樨科）中进化；南非油花/油蜂系统的年代不太清楚。最年轻的油脂花类群包括 Calceolaria（蒲包花科）、Iridaceae、Krameria（苦槛蓝科）和许多 Orchidaceae，其中许多只有几百万年的历史。在蜜蜂中，采油进化至少发生了 7 次，可以追溯到至少 56 Ma（Ctenoplectra）和 53 Ma（Macropis）。在四个地理区域中的三个（但不是全北极地区）都有较老和较年轻的产油类群共存，这意味着采油蜜蜂在进化过程中获得了额外的油源宿主。这种生态位拓宽可能始于对在气味或颜色上类似于油源的花朵的探索性访问，正如涉及油花的几个 Muellerian 或 Batesian 拟态案例所表明的那样。
