Origin of angiosperm characters

Abstract

Models of origin for the typical angiosperm leaf, flower, stamen, pistil and double fertilization are based on evolutionary trends in proangiosperms. It is suggested that angiosperm organs are of chimeric origin, acquired by aggregation and fusion of progenitorial structures. These morphological processes might involve different proangiosperm lineages in unstable (ecotonal, tectonically active) environments. An advantage of early angiosperms in such environments might be due to extended evolutionary potentials of their chimeric organs capable of acquiring new functions related to entomophily and zoochory.