根據形態及發育特徵重建的塔蘚科（灰蘚目）親緣

Phylogeny of the Hylocomiaceae (Mosses, Order Hypnales) Inferred from Ontogenetic and Morphological Characteristics

本研究利用分歧分類學分析二十九個形態特徵以及鱗毛，中央束及腋生毛的發育特徵重建塔蘚科植物的親緣，有別於傳統的特徵觀念，本研究認定整個發育序列為特徵，並利用外群比較極化特徵。以PAUP軟體分析的結果，重建出二個等簡約的演化樹，並支持塔蘚科植物為單起源，包含了塔蘚、假蔓蘚、薄皮蘚、星塔蘚、新船葉蘚、大木蘚、薄膜蘚及圓蒴蘚等八屬，並與灰蘚科最為近緣；塔蘚科的診視特徵為具有合軸的生活型，但在圓蒴蘚則回溯成單軸型；垂枝蘚、擬垂枝蘚、赤莖蘚及扭垂枝蘚從塔蘚科中剔除，但形成一單源群垂枝蘚科。根據此一重建的親緣，同源假說藉由Patterson的相似性、同存性及一致性三測驗進行測試。在塔蘚科中，直立葉不具波紋以及缺乏葉狀的假鱗毛為原始共同特徵；而在科內階層，直立的孢蒴具有退化的蒴齒為同源構造（亦即來自共同的祖先）。非同源構造亦提供了解形態演化機制的訊息，本研究緣用一融合天擇學者及構造學者觀點的互補方法論，蘚類鱗毛的趨同演化歸因於環境的天擇；而輸導組織的建構則受功能限制體調節；假蔓蘚中心束的回蒴演化則說明發育的限制體限制發生過程的變異的作用；異時性藉著截斷或延長發育的序列則是在塔蘚科常見的形態演化模式。而腋生毛在成體時期保有幼體特徵存在於星塔蘚、擬塔蘚及假黃鮮或者在塔蘚、粗枝蘚及垂枝蘚延長其祖先型特徵的平行演化都可能歸因於發育的限制體。

The phylogeny of Hylocomiaceae is inferred by cladistic analyses of twenty-nine morphological characters and the ontogenetic sequences of paraphyllia, central strands, and axillary hairs. The entire ontogenetic transformations are recognized as characters, and character variation is polarized by outgroup comparisons. Two equally parsimonious trees produced by heuristic searches of PAUP support the monophyly of the Hylocomiaceae, which is closely related to family Hypnaceae, containing eight genera Hylocomium, Loeskeobryum, Leptocladiella, Hylocomiastrum, Neodolichomitra, Macrothamnium, Leptohymenium, and Orontobryum. Hylocomiaceae is diagnosable by sympodial growth-form, excepting Orontobryum. The genera Rhytidium, Rhytidiadelphus, Pleurozium, and Rhytidioposis are excluded from the Hylocomiaceae and comprise a monophyletic family, Rhytidiaceae. Based on the reconstructed phylogeny, homology is tested by Patterson's tests of similarity, conjunction, and congruence. In Hylocomiaceae erect leaves without plication and absent of foliose pseudoparaphyllia are found to be symplesiomorphies; at the infrafamilial level erect capsules with reduced peristomes are homologous (i.e., derived from a recent common ancestor). Homoplasies also provide useful insights into understanding the mechanisms of morphological evolution. A complementary methodology synthesizing adaptationist and structuralist perspectives is employed. Convergent evolution of paraphyllia in mosses is ascribed to environmental selection. The Bauplan of conducting tissue in mosses is attributed to functional constraints. Reversed evolution of central strands in Loeskeobryum is a manifestation of developmental constraints, which channel the variation of the ontogenetic pathway. Heterochrony by truncating (paedomorphosis) or extending (peramorphosis) the ontogenetic sequences is a common mode of morphological evolution in the Hylocomiaceae. The parallel evolution of axillary hairs by retention of juvenile morphology at the adult stage in Hylocomiastrum, Hylocomiopsis, and Actinothuidium or extending the terminal stage of ancestral state in Hylocomium, Gollania, and Rhytidium is ascribed to morphological constraints.