Mack A L
Wildlife Conservation Society--PNG Program, Box 277, Goroka, EHP, Papua New Guinea.
J Biosci. 2000 Mar;25(1):93-7. doi: 10.1007/BF02985186.
Relatively few studies have examined the evolution of the mutualism between endozoochorous plants and seed dispersers. Most seed dispersal studies are ecological and examine the role of fruit pulp in promoting seed dispersal. This interaction is often assumed to have originated due to selection stemming from seed dispersers. Here I suggest a "defence scenario" wherein fleshy fruits originated as mechanisms to defend seeds and secondarily became structures to promote seed dispersal. I suggest that frugivory followed from herbivores that specialized on consuming seed defensive tissues and that enhanced seed dispersal was initially a consequence of seed defence. The proposed defence scenario is not posited as an explanation for the sequence that led to all modern frugivores. However, it is suggested that seed predation was the initial source of selection that led to fleshy fruits; the necessary precursor to frugivory. Support is described from the fossil record and from modern structures and interactions. Testable predictions are made in hope that greater interest will be focused on the defensive role of fleshy fruit pulp both in modern interactions and historically.
相对较少的研究探讨了内寄生植物与种子传播者之间互利共生关系的演变。大多数种子传播研究属于生态学范畴，研究果肉在促进种子传播中的作用。这种相互作用通常被认为是由于种子传播者的选择而产生的。在此，我提出一种“防御假说”，即肉质果实最初是作为保护种子的机制而产生的，其次才成为促进种子传播的结构。我认为，食果行为源于专门以种子防御组织为食的食草动物，而增强的种子传播最初是种子防御的结果。所提出的防御假说并非旨在解释导致所有现代食果动物出现的顺序。然而，有人认为种子捕食是导致肉质果实出现的最初选择来源，也是食果行为的必要前提。文中描述了来自化石记录以及现代结构和相互作用的证据。还做出了可检验的预测，希望能让更多人关注肉质果实果肉在现代相互作用和历史上的防御作用。
