Needles versus leaves in ancient plants

Before flowering plants (angiosperms) appeared on earth, conifers (gymnosperms) ruled the roost in the plant world. But the rapid radiation of angiosperms pushed most conifers into marginal habitats around 65 million years ago.

However a recent study (Biffin et al 2011), using molecular methods to determine the genetic relationship amongst species, investigated the idea that evolving a more flattened leaf shape, rather than a typical pine needle, allowed some conifers in the southern hemiphere, known as podocarps, or plum pines, to co-exist with flowering plants. A more flattened leaf shape allows the podocarps to capture more light under the canopy formed by leafy angiosperms.

By evolving flattened leaves podocarps have become one of the most successful conifer groups (Photo courtesy of Professor Bob Hill, University of Adelaide)

The study pinpoints the changing shape of the podocarp leaf shape as beginning around 60 million years ago. Competition between podocarps and angiosperms resulted in flattened leaves evolving several times among conifers, and drastically affecting the geographic range of podocarps – today their highest diversity is found in tropical rainforests.

‘Pine evolved to resist rise of flower power’ ABC Science (website),  Wednesday, 8 June 2011 by Rachel Sullivan (relating to Biffin et al 2011, publication):

For more information see: Biffin et al. (2012) Leaf evolution in Southern Hemisphere conifers tracks the angiosperm ecological radiation. Proceedings of the Royal Society, Biological Science. doi: 10.1098/rspb.2011.0559


About Prof Andy Lowe

Prof Andy Lowe is a British-Australian scientist and expert on plants and trees, particularly the monitoring, management and utilisation of genetic, biological and ecosystem resources. He has discovered new species, lost forests, championed to eliminate illegally logged timber in global supply chains, served the UN’s Office of Drugs and Crime and has been responsible for securing multi-million dollar research funding. He is an experienced and respected executive leader, as well as mid-career mentor. Andy is the inaugural Director of Food Innovation at the University of Adelaide serving as the external face for all significant food industry and government sectors across South Australia, and the world.
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One Response to Needles versus leaves in ancient plants

  1. Pingback: Why do tropical plants have such big leaves? – Prof Andy Lowe

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