Study suggests flowering plants may have originated much earlier

Flowering plants, a major ecological building block, originated in an older era than scientists previously thought. This study, too, can open new avenues of exploration to learn about genetic makeups of other plant types.

Just as well, too. A new study has upped the age of flowering plants by up to 75 million years. The standard theory is that flowering plants originated in the late Jurassic or early Cretaceous. This study is pointing much further back, to the early Triassic. This is very big news, because the flowering plants, whose generic name is “angiosperms”, are one of the major ecological structures of the world. That increase in age could explain quite a lot. Although angiosperms are related to other forms of plants, their biology is quite different in many ways. It’s complex biology, and it needs some explanation. An entire class of plant can’t just start up at the levels of complexity of the currently considered forms of earliest angiosperms. ** Putting together the history of flowering plants hasn’t exactly been easy. Nor has it been exactly organized, in terms of sequencing the available information. When I was a kid, the magnolia was referred to as “one of the earliest flowering plants”. Think about the complexity of an organism like a magnolia tree, and you can see a few missing pieces of the puzzle. A plant that complex doesn’t just happen. In short, the entire history of flowering plants has had to be assembled, piece by piece, and the actual point of origin hasn’t been identified. Matters aren’t much simplified in that the types of plants which predate flowering plants are pretty different, being seaweeds and gymnosperms, plants like cycads and conifers. In any other science, this level of discontinuity would be appalling, but in paleo it’s quite normal. “Deducing an ocean from a drop of water” is the standard practice. So the new study by the National Evolutionary Synthesis Center (NESCent) is actually likely to be very welcome, because data which can open up new avenues of exploration is often exactly what fills in the gaps. NSECent has more than earned its keep in more ways than one with this study. The approach included genetic studies of other plant types, and the insect factor, the history of insects which work with the flowering plants, like bees and flies. (Excuse me for not simplifying the basis of this study. I can’t, because it’s not simple, except in very basic principles. This is a correlative approach, looking for ecological relationships with flowering plants, and it’s an excellent scientific method for dealing with missing data. That also means a description of it doesn’t fit into a few sentences.) Interestingly, the previous estimate of the origin of flowering plants was long after these insects are known to have evolved. That doesn’t quite ring true, and the known relationship of insects and flowers, which is practically symbiotic in modern times, had to start somewhere. The key to this study is the fossil record. The correlative studies were a good match for other plant groups, but the fossil record for flowering plants is pretty sparse, and therefore not much help. There just aren’t any fossils of flowering plants which go back as far as the NEScent survey suggests they should. (Paleo fans will be smiling and groaning sympathetically at the very familiar sight of having a calendar with a June but not knowing where the January is.) It’s quite likely that a real hunt will now develop for the origins of the angiosperms, thanks to NEScent's work. The information from the survey has exposed some likely suspects, now it’s a matter of getting fossil support. It’ll be extremely interesting to see how they approach that problem, but it’ll also be good science, figuring out how to pin down an ecological situation where early flowering plants would have been able to evolve. Forensic paleontology is about as simple as it sounds, but it’s quite possible that something like a speck of Triassic amber with a pollen grain could answer the origin question to some extent. If I might suggest: There are clues to possible fossil sites for early angiosperms: The ecological requirements for gymnosperms and angiosperms are so different, that you can rule out areas known to have been full of gymnosperms, particularly conifers. Their growth habit is designed to obliterate competitors. Areas with less drainage would be better for angiosperms, because they’d have less competition. ** One of my working theories is that the big Global Dryouts of the past could have had a lot to do with angiosperm biological development. Cycads, ferns, and the other dino-era plants are very tough, but they need water. Conifers are by far the most resistant to dry spells, but not immune. Angiosperms, on the other hand, aren’t quite as fully controlled by dryouts. Quite the opposite, in that environment, because they seem to have benefited. The dryouts would have happened at the expense of their competition. Many of them have levels of drought resistance. Cacti, for example, were originally jungle plants, understorey in the ancient ecology. They, and other succulents, obviously developed their own water management biology. The flowering plants would have taken a long time to develop their super efficient reproductive systems, too, which are quite different from the gymnosperms.