Image: Wikimedia Commons.

Image: Wikimedia Commons.

Picking up on my ele­mental theme, fire has long been con­sidered a major influ­ence on evol­u­tion of the angio­sperms, whether nat­ural or anthro­po­genic con­flag­ra­tions. This incen­di­ary inter­ac­tion has not been helped by plants them­selves, which not only gen­er­ate highly cal­or­ific and com­bust­ible dry mat­ter but also provide the oxy­gen needed to per­mit their com­bus­tion. The dra­matic effect of fire on veget­a­tion was graph­ic­ally demon­strated in the Australian wild­fires in January. Although fire has been an abi­otic factor for hun­dreds of mil­lions of years, the ori­gins of so-called ‘fire prone’ floras have hitherto been con­sidered to be com­par­at­ively recent phe­nom­ena. However, using a molecular-dated phylo­geny for the Proteaceae, a ‘great Gondwanan fam­ily with a 113-million-year evol­u­tion­ary his­tory’, Byron Lamont and Tianhua He have estab­lished that angio­sperm fire prone­ness can now be traced back 83–94 mil­lion years into the ‘fiery Cretaceous’. Furthermore, the asso­ci­ated evol­u­tion of on-plant (serot­iny; in which seed release occurs in response to an envir­on­mental trig­ger, e.g. fire) and soil seed stor­age, and – evol­u­tion­ar­ily – more recent ant-dispersal char­ac­ter­ist­ics, affirms those beha­viours as ancient adapt­a­tions to fire among flower­ing plants. Interestingly, and by way of set­ting up some sort of com­pet­i­tion between angio– and gym­no­sperm, Tianhua He et al. have pre­vi­ously sug­ges­ted126-million-year evol­u­tion­ary his­tory of fire-adapted traits in the Pinaceae. And if you want more on the evol­u­tion­ary suprem­acy tussle between those great seed-bearing phyla, then I can recom­mend Clément Coiffard et al.’s paper that pro­poses a win­dow of oppor­tun­ity of approx­im­ately 145–66 mil­lion years ago (the Cretaceous Period) dur­ing which angio­sperms rose to dom­in­ance over the gym­no­sperms – and all other mem­bers of the Plant Kingdom.

[A video blog on the Proteaceae can be found else­where on this site – Ed.]

Nigel Chaffey. ORCID 0000-0002-4231-9082

Nigel is a botanist and full-time academic at Bath Spa University (Bath, near Bristol, UK). As News Editor for the Annals of Botany he contributes the monthly Plant Cuttings column to that august international botanical organ. His main goal is to inform (hopefully, in an educational, and entertaining way...) about plants and plant-people interactions.

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