PUBLISHED: 7 JULY 2015 | ARTICLE NUMBER: 15106 | DOI: 10.1038/NPLANTS.2015.106 editorial Jurassic bark

The subject of extinction and de-extinction are much in the news at the moment, but discussions tend to focus on the loss or resurrection of charismatic animals like tigers or tyrannosaurs. Where is the talk of the plant species that have been lost and that might be worth bringing back?

Last month saw Jurassic World break box year a study from Daniele Silvestro and only know of it from archaeological samples office records across the globe. Like the colleagues specifically looked at the effect of of discarded nut cases and pollen preserved previous three films in the franchise it the great mass extinction events on plants in lake beds. It was the arrival of humans wonders what it would be like for humans (New Phytol. 207, 425-436; 2015). This between 700 and 1100, or the rats that came to walk with dinosaurs. This is no new idea analysis used Bayesian statistics to estimate with them, that sounded the death knell for in fiction dating back to Arthur Conan extinction and speciation events in plants the island’s forests. Doyle and Jules Verne, but serious scientific based on the known fossil record. They Another plant worth resurrecting attempts are now being made to bring back found that plant species have been far less would be silphium, used in and around species from beyond extinction. affected by these major global events. the Mediterranean until the third or In 2009 scientists used cloning to Plants did suffer increased rates of second century bc. This herb was used produce an individual of an extinct species, extinction at these times of considerable in cooking, as a medicine for all kinds of the Pyrenean ibex. The procedure used environmental change, but the losses were aches and pains and also as a contraceptive. tissue cultures originating from the last less dramatic than seen for animals and The great demand for the plant in the surviving individual prior to its death in plant net speciation recovered more quickly. ancient world — the Romans valued it as 2000 (a far cry from mosquitoes preserved In fact the data for plants alone identified worth its weight in silver coins — drove in amber) and the clone only lived for just three mass extinctions echoing an it to extinction by overconsumption. seven minutes due to a lung defect, but earlier study by B. Borja Cascales-Miñana, B. Resurrecting silphium would be particularly a precedent has been set. Other research & C. J. Cleal (Terra Nova 26, 195–200; 2014) difficult, however, as no samples of it projects are attempting to recreate animals that saw only two mass extinctions of plants. remain and there is no consensus on its such as the quagga (a subspecies of zebra) One consequence of this may be that losses precise identity. and the auroch cattle of Pleistocene Europe of whole classes of plant are rare, making Or wouldn’t it be fun to have examples by selective breeding from modern relatives. living relatives of extinct plant species more of the tulips that were at the heart of the Genome editing has been proposed for common than for animal groups. economic turmoils in Holland in the 1600s? re-engineering woolly mammoths or However, a multitude of plant species At that time, tulips were a highly prized reintroducing dinosaurian characteristics have been lost. Which would make good commodity and uncontrolled speculation into modern birds. In all this there is candidates for resurrection? For the drove prices up to untenable levels before no talk of recreating the flora of ancient spectacle alone Araucaria mirabilis would the bubble burst and they abruptly crashed. times. Is this simply an example of anti- be a contender. These pine trees grew in the At the height of ‘tulip madness’ a bulb of plant discrimination or is there some Jurassic period and are preserved in great the variety Semper augustus was traded for other reason? numbers in Cerro Cuadrado Petrified Forest, 12 acres of land and that of Viceroy for the Species go extinct and new ones emerge Patagonia. They grew up to 100 m tall and equivalent of sixteen times the annual wage all the time. However, there have been at had cones almost 10 cm in length. of a skilled labourer. Illustrations of those least five global mass extinctions in the Or how about Aglaophyton major, which flowers are all that remain. history of life on Earth, short periods when lived in the Devonian era (around 410 Ma) The idea of using genetic engineering large numbers of species, genera and even and is found as fossils in the Rhynie chert to de-extinct lost species may sound larger groupings cease to exist. The most deposits in Aberdeenshire, Scotland? It was farfetched and there are substantial barriers recent occurred at the end of the Cretaceous a plant right at the cusp of developing a true to overcome before we will see live examples period some 66 million years ago (Ma), vascular system and was among the first to of Tasmanian tigers or dodos. But the triggered by an asteroid hitting the earth associate with mycorrhizal fungi. A. major is exact same approaches being applied to somewhere off the coast of Mexico, which a relative of modern club mosses as are the those projects are available in plant biology resulted in the loss of three quarters of Lepidodendron or scale trees. These lived in and the techniques of plant breeding, animal species. We may currently be in the the Carboniferous period (360 Ma) and had such as the generation of individuals middle of a sixth mass extinction driven by trunks covered not with bark but with soft from calli, may make it easier for budding our own activities. For example, a paper by scaly tissue, sometimes mistaken for the skin phytoresurrectionists to exhume their G. Ceballos et al. last month (Sci. Adv. 1, of some giant fossil snake. extinct species of choice. e1400253; 2015) estimated that the rate of As the Jurassic World theme park is sited Of course the genetic engineers in species extinction over the last century was on an island (Isla Nuba about 120 miles off Jurassic World do not confine themselves to up to 114 times higher than the expected the coast of Costa Rica) it might be sensible dinosaurs that once lived, but begin to create background rate. to reengineer a whole island flora, say that whole new species: bigger, scarier and with Research into mass extinction events of Easter Island (Rapa Nui), and with it the more teeth. So perhaps we should consider tends to concentrate on animal species majestic palm, Paschalococos disperta. This making a Triffid; an excellent source of and particularly vertebrates, which leave may have grown to 15 m tall and so been the biofuel oil whose venom has impressive the best fossils. However, earlier this tallest palm alive at that time but we now pharmacological potential. ❐

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