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Taylor (2009), Xin Wang (2009), Dilcher (2010), Magallón (2010), Stephen A. Stewart and Rothwell (1993) recapitulated the main steps needed to form the conduplicate carpel using glossopterid-, other seed fern-, and early angiosperm fossils as examples. Cambridge: Cambridge University Press, 521 pp., with additional comments distilled from E. Further, White proposed that the glossopterid Megafructi were a second basal group upon which ranalian angiosperms, monocotyledonous flowering plants including Pandanus (Pandanaceae, Pandanales, Arecidae), Williamsonia (a bennettitalean), additional cycads, and certain other angiosperms evolved (M. Principal morphologic innovations in angiosperms and gymnosperms according to Krassilov (1997) are: Paleoherb hypothesis. Burger published a paper in 1981 suggesting that the earliest angiosperms were monocotyledonous plants. Molecular tracers include naturally occurring but fossilized triterpenoids known as oleanone triterpanes (oleananes). These TSBs are a stratigraphically-important but "inconvenient truth," which is often buried or ignored in modern syntheses on the origin and evolution of flowering plants. Flowers and simple cones are reproductive short- (spur-) shoots according to Christianson and Jernstedt (2009).

A novel "Mosaic Theory for the Evolution of the Dimorphic Perianth" proposed by Warner et al. Melville develops his earlier ideas on a Gonophyll Theory (1969) in a review published in 1983 that proposes a Permian origin of angiosperms from glossopterids. Rothwell (1993), Paleobotany and the Evolution of Plants (second edition). Mary White (1986) proposes that glossopterid Microfructi were basal to several parallel but sometimes branching and reticulate lines of evolution leading to the Caytoniales, angiosperms, Cycas (Cycadaceae, Cycadales), Podocarpaceae (Podocarpales), Araucariaceae (Araucariales), and certain catkin-bearing angiosperms including the Casuarinaceae. The polyphyletic-polychromic-polytopic hypothesis (Z.-Y. Cyclic angiospermization is reviewed by Krassilov (1997) and Ponomarenko (1998) within the context of a polyphyletic origin of angiosperms. Clifford (1982), The Monocotyledons: A Comparative Study. A discussion of this theory and how it links to the anthophyte hypothesis is presented by T. A few elements of ideas proposed by Cascales-Miñana et al. Armen Takhtajan's often criticized proposal on a "neotenous" origin of flowering plants (1969, 1976, and previous papers) is my starting place. Equally puzzling is that despite intense interest in the origins of seed plants and angiosperms throughout the entire last century, few have looked at the problems from a life cycle evo-devo perspective, with perhaps one exception (Takhtajan 1976), who alluded to neoteny as one of the possible mechanisms contributing to the origin of angiosperms." "Some authors seem curiously determined to prove that pre-Cretaceous fossils are crown-group angiosperms, but for understanding most aspects of the origin of angiosperms [other than their age], close stem relatives would be far more significant ..." (page 318, J. Doyle 2012) Based on four decades of study of the problem by Professor Emeritus J. Doyle, where on the Pangaean continent (and when) do students of angio-ovuly and the origin of flowering plants focus the search for "close stem relatives" of the group? Surprising and often ignored clues shedding light on the shadowy origin of flowering plants originate from oil and gas exploration data and the geochemistry of taxon-specific biomarkers (TSBs) and molecular traces, which are recoverable from mud logs of well boreholes, or from coal balls, compressions, and permineralizations (Moldowan and Jacobson 2002). Mud-loggers are able to ascertain higher plant input into a core segment of a stratigraphic horizon pulled-up from the well-site gas chromatography and mass spectrometry, and microscopic analysis of animal and plant microfossils including pollen and vascular plant fragments in core samples. Rudall (2006), Morphological and molecular phylogenetic context of the angiosperms: contrasting the 'top-down' and 'bottom-up' approaches used to infer the likely characteristics of the first flowers, Journal of Experimental Botany 57(13): 3471-3503. Flowering plants probably did not appear "suddenly," and the concept of a so-called "first flower" including proposals published by Albert et al. The reproductive short- (spur-) shoots of these Permo-carboniferous seed plants were equivalent to theoretical constructs of the protoflower proposed by Leppik (1960, 1968).

Some of the historical syntheses include Arber and Parkin (1907), I. Bailey (1949), Edgar Anderson (1934), Axelrod (1952, 1970), Leppik (1960, 1968), Raven and Kyhos (1965), Cronquist (1968), Thorne (1968), Melville (1969), Takhtajan (1969, 1976, 1991), Raven and Axelrod (1974), Stebbins (1958, 1974), C. Beck (1976), Hughes (1976, 1994), Meeuse (1979), Nair (1979), Krassilov (1977), Retallack and Dilcher (1981 [two papers]), Asama (1982, 1985), Melville (1983), Crane (1985), Meyen (1986, 1988), Dilcher (1986, 2000), J. Doyle and Donoghue (1986, 1987), Endress (1987), Friis et al. If the answer to the preceding question is "yes," how does this evo-devo mechanism affect arthropod antagonist body allometries and population ecology? Further, the evo-devo of flight is yet another conundrum in paleoentomology (Grimaldi and Engel 2005). Poleward migration of early angiosperm flora - angiosperms only displaced the relict Jurassic-type flora at high latitudes in late Cretaceous time.

(2017) compile particularly relevant reference lists. Flowering material of Degeneria vitiensis is shown in the right-hand image (photographed by Paddy Ryan, Ph. Fragrance of this species resembles Cananga odorata according to Professor Al Smith (A. While discussing the effects of ice-house/hot house planetary climatic switches on expansion of land plant invertebrate herbivores Labandeira (2006) states: "One possibility is that these atmospheric variables have direct physiologic consequences on the selection and turnover of particular plant clades globally, which in turn elicit an associational response from selected clades of insect herbivores." The preceding statement is quoted from page 425 of C. Labandeira (2006), The four phases of plant-arthropod associations in deep time, Geologica Acta 4(4): 409-438. Additional compilations on the origin of angiosperms and floral morphology include Krassilov (1991), Thorne (1992), Endress (1993, 2001 [a book chapter and two papers], 2004), Friedman (1992 [two papers]), Stewart and Rothwell (1993), Nixon et al. Studies on Drosophila melanogaster eggs, specifically, artificial size-selection experimentation, affects larval patterning and body allometry (Miles et al. Do host seed plant brassinolides and other hormones affect insect antagonist egg size, potentially controlling larval tissue patterning? At the very earliest, flying insects were known from the Devonian Period.

Coevolution between phytophagous insect antagonists and Carboniferous, Permian, and Triassic seed plant hosts at the level of their respective developmental tool kits with focus on selective forces that drive the logic of transcriptional regulation is proposed in the following essay to explain the origin and evolution of flowering plants and certain Holometabola. A second species of Degeneria has been reported (A. Despite several decades of effort by morphologists, paleobotanists, and plant biologists, the origin of angiosperms remains enigmatic and mysterious. Taylor and Hickey (1996 [a book and one paper]), D. Interestingly, many naturally-occurring plant sesquiterpene esters and lactones are bioactive and exhibit insecticidal properties. Molecular diversification of the Hox gene complex over the course of 600 million years of metazoan evolution is analogous to the 400 million year old molecular evolution of MIKC-type MADS-box genes and related cis-acting TFs of land plants (Theißen et al. Evolution of the Hox complex probably involved small gene duplications, WGDs, divergence of homeodomains, disintegration of the Hox cluster at breakpoints, and rapid changes in the nucleotide sequence of homeodomains (S. Shrub-like lignophytes or small trees produced reproductive modules, which were exploited by flying insects. 2007) and caste polyphenism in holometabolous wasps (J. Understanding the nature and timing of early molecular diversification of homeotic selector genes, developmental proteins, nuclear receptor proteins, and cis-acting TFs of both invertebrate antagonists and vascular plant hosts might be a critical first step in understanding the Paleozoic origin of holometabolous insects and their putative coevolution with the earliest angiosperms.

I discuss potential coevolution of insect and seed plant helix-turn-helix proteins, specifically Engraled and Leafy enzymes that bind to cis-regulatory promoters controlling downstream expression of genes determining paedomorphic insect body patterns and plant cone and floral organ development. (2017) report low support ( The Fiji Islands have long been of interest to biogeographers (Raven and Axelrod 1974, Thorne 1986, Morley 2001), to geologists as a tectonic puzzle (Rodda and Kroenke 1984), and to botanists as a "cradle of flowering plants" (title, Chapter 12, Takhtajan 1969), where some "missing links in the chain of angiosperm phylogeny" are known (page 141, Between Assam and Fiji, Takhtajan 1969). There are several conifers endemic to the Fiji Archipelago including Agathis vitiensis, Acmopyle sahniana, Dacrycarpus imbricatus, Dacrydium nausoriense, Dacrydium nidulum, and Decussocarpus vitiensis. The only known species at the time, Degeneria vitiensis (pictured below), combines a number of primitive features that have ignited many debates (I. Some paleontologists regard the problem of flowering plant origins, "... Juvenile hormone and its homologs are integral in vitellogenesis (Hartfelder 2000), regulation of moult cycles (Truman and Riddiford 2002), and caste development and behavior in social Hymenoptera (Guidugli et al. Were bioactive brassinolides and sesquiterpenes manufactured by Paleozoic seed plants used as chemical warfare agents to affect growth, development, and behaviour of herbivorous insects? Another avenue of deduction somehow ties-in insect evo-devo of wings from gill halteres with increases in atmospheric oxygen during the De CARB. The place and time to begin a molecular phylogenetic analysis is the late Frasnian-Famennian Age hypoxic icehouse that extended into the Tornaisian Age of the Carboniferous Period.

Arthropod body allometry is intertwined with development of larval and imaginal disc tissues (Stern and Emlen 1999, Shingleton et al. 1997), Ubx (Pavlopoulos and Akam 2011), and the field-specific selector gene necessary for limb development in Drosophila (Diptera) known as dll (S. Fushi-tarazu protein encoded by the ftz gene, intracellular tertiary enzyme structure folding environments, and the apparent flexibility of Ftz and other Hox proteins in the evolution of arthropods, are discussed in a recent review by Merebet and Hudry (2011). These studies, among others underway or already published by Sean Carroll and colleagues, underscore the importance of Hox proteins in evolution of the arthropod tool kit. Mesozoic paleogeography and early angiosperm history. The image above is the northwestern face of the Korombasabasaga Range, Viti Levu Island, Fiji as viewed from the road between Namosi and Wainimakutu villages. A review of neotenous development in termites is available (Korb and Hartfelder 2008). Structurally similar to bioactive plant brassinosteroids, 20E-ecdysone induces a cascade of TF biosynthesis important in the regulation of insect development (Truman and Riddiford 2002, De Loof 2008). One line of paleobiological thinking hypothesizes that insects took flight to exploit new habitat. Did ingestion of seed plant brassinosteroids by pterygote insects affect the evo-devo of wings from thoracic limb pads and JH signaling? The evo-devo of insect caste polyphenism is reviewed by Emlen and Nijhout (2000). Thummel and Chory (2002) point to a possible coevolutionary connection between the 20E-ecdysone/cytochrome P biosynthetic machinery of insect antagonists and seed plant hosts. Further, changes in the arthropod homeodomain and evolution of new protein motifs led to new Hox developmental tool kit functions in certain insect lineages (S. The paleobiology of insect flight in relation to the advent of arthropod-seed plant mutualisms remains unexplained. Studies of evolving allometries and body plans might help us understand a possible coevolutionary origin of angiosperms and certain clades of holometabolous phytophagous insect antagonists. Molecular control over arthropod growth varies among the major clades of insects (Grimaldi and Engel 2005). 2007) could potentially be discerned in the fossil record. (2005) review molecular evolution of homeotic genes and homeodomain TFs needed to understand regulation of body ground plan development in phytophagous arthropod antagonists.

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