Keywords
1. Jurassic flowering plants
2. Angiosperm evolution
3. Fossilized flowers
4. Paleobotany
5. Nature Plants journal
In the serene amber of time, encapsulated within the enduring pages of “Nature Plants,” a note of monumental significance to the botanical world reverberates through the academic ether. Jennifer R. Mandel’s 2019 commentary on a critical moment in the evolutionary chronicle of plants heralds an era when flowering plants—angiosperms—first graced the tapestry of the Earth. With the weight of geological eons behind it, the diminutive reference number 31061534 becomes our guiding star in this exploration of ancient floral beginnings within the storied Jurassic period. Accompanied by the Digital Object Identifier (DOI) 10.1038/s41477-019-0423-y, our expedition transcends time as it delves into the heart of paleobotanical research, its implications and the profound transformation it imparts upon our understanding of the botanical tree of life.
As the sun rises on the Jurassic age, a time renowned for its colossal reptilian denizens, a quiet revolution unfolds beneath the expansive ferns and cycads. It is here, amidst the shadowy underbrush, that the first semblots of flowering plants tentatively spread their petals. Their arrival on the primordial stage does not trumpet with the roar of the dinosaurs nor does it shake the very foundations of Earth. Instead, their emergence signifies an evolutionary leap, transforming not only the prehistoric terrains but also setting in motion a legacy that will eventually craft the modern Earth’s diverse ecosystems and alter the course of life itself.
Jennifer R. Mandel, from the Department of Biological Sciences at the University of Memphis, in her pivotal commentary published in May 2019, ignites curiosity surrounding the timing and rise of these ancestral flowering plants (Mandel, J. R. Nat. Plants, May 2019, 5(5), 455-456, DOI: 10.1038/s41477-019-0423-y). Her insights are drawn upon findings that push back the clock on the advent of flowering plants to an era when dinosaurs like Brachiosaurus and Allosaurus roamed the Earth.
The traditional view of angiosperm evolution suggested a Cretaceous dominance, approximately 100 million years ago, when flowering plants began to radiate diversely, according to William E. Friedman’s earlier work (Friedman, W. E. Am. J. Bot., 96, 5–21, 2009, DOI: 10.3732/ajb.0800150). This perspective lent to the notion that angiosperms were latecomers to the ecological theatre, rapidly diversifying to fill ecological niches.
Recent discoveries, however, unearthed from the fertile loam of research, have reshaped this narrative. A series of groundbreaking studies—like those referenced by Mandel, including extensive molecular analyses of living plants (Zeng, L. et al. Nat. Commun., 5, 4956, 2014, DOI: 10.1038/ncomms5956) as well as fossil discoveries (Li, H.-T. et al. Nat. Plants, 2019, DOI: 10.1038/s41477-019-0421-0)—paint a dynamic portrait of a lineage stretching its roots back into the mists of the Middle Jurassic, nearly 170 million years ago, a timeframe substantiated by recent genomic assemblies (Wickett, N. J. et al. Proc. Natl Acad. Sci. USA, 111, E4859–E4868, 2014, DOI: 10.1073/pnas.1323926111).
Mandel’s discourse invites an exploration of the relevance of this timeline revision. What does it mean for our understanding of ancient ecosystems, the co-evolution of plants and pollinators (Misof, B. et al. Science, 346, 763–767, 2014, DOI: 10.1126/science.1257570), and for the phylogenetic placement of angiosperms alongside their gymnosperm counterparts?
The dating of these evolutionary events is ushered forth by not only fossil evidence but also through the marriage of molecular sequencing and advanced computational analyses. These alliances render unto science a powerful tool to calibrate the molecular clocks within plant lineages, tracing genetic markers through their most minute mutations across the vastness of time. It is a pursuit that has seen contributions from diverse fields including entomological studies on the evolution of insects (McKenna, D. D. et al. Syst. Entomol., 40, 835–880, 2015, DOI: 10.1111/syen.12132) and further understanding of plant-insect interactions dating back to the days when dinosaurs acted as unlikely gardeners (Farrell, B. D. Science, 24, 555–559, 1998, DOI: 10.1126/science.281.5376.555).
Embracing the insights gleaned from these Jurassic floral pioneers, scientists like Mandel seek to unravel aspects of their reproductive strategies, pondering whether these flowers bore the colorful allure meant for animal pollinators or resorted to more primitive means of procreation. It is a quest that plunges phytologists into the curious world of Cretaceous florae and their potential interactions with the insects of the time, aiming to decipher whether these plants produced nectar or relied solely on the wind for pollination. A pertinent study, conducted by McKenna and colleagues, investigates how plant-insect interactions potentially drove the diversification of angiosperms (McKenna, D. D. et al. Syst. Entomol., 40, 835–880, 2015, DOI: 10.1111/syen.12132).
The paper by Mandel contextualizes the significance of these questions within the broader landscape of evolutionary biology, grounding the discourse in the importance of reconstructing accurate phylogenies for the angiosperm lineage. The latest molecular and fossil evidence suggests the presence of angiosperms in the Jurassic coincides with the peak diversification of many major insect clades (Farrell, B. D. Science, 24, 555–559, 1998, DOI: 10.1126/science.281.5376.555; McKenna, D. D. et al. Syst. Entomol., 40, 835–880, 2015, DOI: 10.1111/syen.12132), paving the way for a fascinating hypothesis where the early emergence of flowering plants may have played an integral role in the diversification of herbivorous insects.
But what did these ancient flowers look like, and how did they function within their ecosystems? Seeking answers, scientists turn to the preserved sepals and petals, pale pollen grains, and subtle seed structures that withstand the test of time. A study released by Li H.-T. et al. documents the morphology of several Jurassic angiosperm species, such as Archaefructus, which bore a striking resemblance to modern-day water lilies, splaying their simple structures atop the waterlogged soils of prehistoric lakebeds (Li, H.-T. et al., Nat. Plants, 2019, DOI: 10.1038/s41477-019-0421-0).
In commenting on these revelations, Mandel not only elevates the debate surrounding the age of angiosperms but also highlights a broader implication. The understanding of early flowering plants propels our grasp of evolutionary patterns and processes, implicating the role of key innovations in angiosperm diversification. Beaulieu et al., in an attempt to pinpoint the origins of modern plant biodiversity, accentuate the need to integrate paleobotanical evidence into the historical narrative of life, underscoring the potential mechanisms of angiosperm success in conquering terrestrial biomes (Beaulieu, J. M., O’Meara, B. C., Crane, P., & Donoghue, M. J., Syst. Biol., 64, 869–878, 2015, DOI: 10.1093/sysbio/syv027).
Bridging studies on seed morphogenesis, Libo Li et al. (Sci. Adv., 1, e1501084, 2015, DOI: 10.1126/sciadv.1501084) delved deep into genomic data, unearthing the molecular stories etched in seed coats that mirror the progress of floral evolution. Their work, alongside others in the field, adds to the burgeoning compendium that attests to the advanced age of flowering plants, much older than previously assumed.
As our article draws to a close, the garden of knowledge cultivated by Mandel and her colleagues continues to flourish, fed by the ceaseless inquiries of curious minds. The Jurassic leap for flowering plants, once an enigma cloaked in amber and stone, now edges closer to the radiant clarity of discovery, allowing us a glimpse into a world where the seeds of our planet’s future biodiversity were sown. For beyond the shadow of the mighty dinosaurs, in the stillness of ancient foliage, blossoms the profound realization that these earliest flowers were, indeed, the harbingers of a floral dynasty that would come to color the world with its boundless resilience and beauty.
Undoubtedly, the compelling narrative crafted by years of meticulous research and Mandel’s thoughtful commentary affirms not just the age of angiosperms but also the crucial evolutionary interplay that underpins the biodiversity we behold today. In this respect, the DOI 10.1038/s41477-019-0423-y not only signifies an academic citation but also marks a beacon for anyone venturing into the enigmatic past of Earth’s flowering heritage—a reminder that even in the face of prehistoric giants, the delicate dance of petals and pollinators resonated with a force that would echo through the ages.
References
1. Mandel, J. R. (2019). A Jurassic leap for flowering plants. Nature Plants, 5(5), 455-456. DOI: 10.1038/s41477-019-0423-y
2. Friedman, W. E. (2009). The meaning of Darwin’s “abominable mystery”. American Journal of Botany, 96(1), 5–21. DOI: 10.3732/ajb.0800150
3. Zeng, L., Zhang, Q., Sun, R., Kong, H., Zhang, N., & Ma, H. (2014). Resolution of deep angiosperm phylogeny using conserved nuclear genes and estimates of early divergence times. Nature Communications, 5, 4956. DOI: 10.1038/ncomms5956
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