Australasian Science: Australia's authority on science since 1938

The Ancestor of All Flowers

Credit: TKphotography64

Credit: TKphotography64

By Charles Foster

An international collaborative project has reconstructed the ancestor of all modern flowering plants. What can it tell us about the evolution of this important group?

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Flowering plants (angiosperms) are among the most successful biological groups on the planet. Estimates for the number of angiosperm species vary, but there are probably at least 350,000 species representing 90% of the diversity of all living land plants.

As expected in a group of this size, angiosperms are incredibly variable. They can exist as anything ranging from small herbaceous annuals to giant woody trees that live long enough to outlast civilisations. Angiosperms can be found in nearly all environments, whether aquatic or terrestrial, and have developed remarkable adaptations to survive, including parasitism of other plants or even carnivory of small animals.

Despite the importance of angiosperms, much of their evolutionary history has remained a mystery. Many outstanding questions remain, including when angiosperms first appeared and what these early angiosperms might have looked like.

The fossil record indicates that angiosperms first appeared not long before 130 million years ago. However, ages of biological groups can also be estimated using molecular clock analyses, which combine knowledge of the fossil record, differences in DNA sequences between modern species, and models of evolution. When the age of angiosperms is estimated using molecular clocks, a far earlier origin is suggested, perhaps up to 250 million years ago. Therefore, the...

The full text of this article can be purchased from Informit.