Question: From Orchids to Variation, what was the main subject of the scientist who coined the term "abominable mystery?"

full_context: Document 1: Flowering plant: Island genetics provides one proposed explanation for the sudden, fully developed appearance of flowering plants. Island genetics is believed to be a common source of speciation in general, especially when it comes to radical adaptations that seem to have required inferior transitional forms. Flowering plants may have evolved in an isolated setting like an island or island chain, where the plants bearing them were able to develop a highly specialized relationship with some specific animal (a wasp, for example). Such a relationship, with a hypothetical wasp carrying pollen from one plant to another much the way fig wasps do today, could result in the development of a high degree of specialization in both the plant(s) and their partners. Note that the wasp example is not incidental; bees, which, it is postulated, evolved specifically due to mutualistic plant relationships, are descended from wasps.
Document 2: Flowering plant: The exact relationship between these eight groups is not yet clear, although there is agreement that the first three groups to diverge from the ancestral angiosperm were Amborellales, Nymphaeales, and Austrobaileyales. The term basal angiosperms refers to these three groups. Among the rest, the relationship between the three broadest of these groups (magnoliids, monocots, and eudicots) remains unclear. Some analyses make the magnoliids the first to diverge, others the monocots. Ceratophyllum seems to group with the eudicots rather than with the monocots.
Document 3: Evolutionary history of plants: By the middle of the Devonian, many of the features recognised in plants today were present, including roots and leaves. Late Devonian free - sporing plants such as Archaeopteris had secondary vascular tissue that produced wood and had formed forests of tall trees. Also by late Devonian, Elkinsia, an early seed fern, had evolved seeds. Evolutionary innovation continued into the Carboniferous and is still ongoing today. Most plant groups were relatively unscathed by the Permo - Triassic extinction event, although the structures of communities changed. This may have set the scene for the appearance of the flowering plants in the Triassic (~ 200 million years ago), and their later diversification in the Cretaceous and Paleogene. The latest major group of plants to evolve were the grasses, which became important in the mid-Paleogene, from around 40 million years ago. The grasses, as well as many other groups, evolved new mechanisms of metabolism to survive the low CO and warm, dry conditions of the tropics over the last 10 million years.
Document 4: Flowering plant: The earliest known macrofossil confidently identified as an angiosperm, Archaefructus liaoningensis, is dated to about 125 million years BP (the Cretaceous period), whereas pollen considered to be of angiosperm origin takes the fossil record back to about 130 million years BP. However, one study has suggested that the early-middle Jurassic plant Schmeissneria, traditionally considered a type of ginkgo, may be the earliest known angiosperm, or at least a close relative. In addition, circumstantial chemical evidence has been found for the existence of angiosperms as early as 250 million years ago. Oleanane, a secondary metabolite produced by many flowering plants, has been found in Permian deposits of that age together with fossils of gigantopterids. Gigantopterids are a group of extinct seed plants that share many morphological traits with flowering plants, although they are not known to have been flowering plants themselves.
Document 5: On the Origin of Species: In the sixth edition Darwin inserted a new chapter VII (renumbering the subsequent chapters) to respond to criticisms of earlier editions, including the objection that many features of organisms were not adaptive and could not have been produced by natural selection. He said some such features could have been by-products of adaptive changes to other features, and that often features seemed non-adaptive because their function was unknown, as shown by his book on Fertilisation of Orchids that explained how their elaborate structures facilitated pollination by insects. Much of the chapter responds to George Jackson Mivart's criticisms, including his claim that features such as baleen filters in whales, flatfish with both eyes on one side and the camouflage of stick insects could not have evolved through natural selection because intermediate stages would not have been adaptive. Darwin proposed scenarios for the incremental evolution of each feature.
Document 6: Flowering plant: The botanical term "Angiosperm", from the Ancient Greek αγγείον, angeíon (bottle, vessel) and σπέρμα, (seed), was coined in the form Angiospermae by Paul Hermann in 1690, as the name of one of his primary divisions of the plant kingdom. This included flowering plants possessing seeds enclosed in capsules, distinguished from his Gymnospermae, or flowering plants with achenial or schizo-carpic fruits, the whole fruit or each of its pieces being here regarded as a seed and naked. The term and its antonym were maintained by Carl Linnaeus with the same sense, but with restricted application, in the names of the orders of his class Didynamia. Its use with any approach to its modern scope became possible only after 1827, when Robert Brown established the existence of truly naked ovules in the Cycadeae and Coniferae, and applied to them the name Gymnosperms.[citation needed] From that time onward, as long as these Gymnosperms were, as was usual, reckoned as dicotyledonous flowering plants, the term Angiosperm was used antithetically by botanical writers, with varying scope, as a group-name for other dicotyledonous plants.
Document 7: On the Origin of Species: On the Origin of Species, published on 24 November 1859, is a work of scientific literature by Charles Darwin which is considered to be the foundation of evolutionary biology. Darwin's book introduced the scientific theory that populations evolve over the course of generations through a process of natural selection. It presented a body of evidence that the diversity of life arose by common descent through a branching pattern of evolution. Darwin included evidence that he had gathered on the Beagle expedition in the 1830s and his subsequent findings from research, correspondence, and experimentation.
Document 8: On the Origin of Species: On the Origin of Species The title page of the 1859 edition of On the Origin of Species Author Charles Darwin Country United Kingdom of Great Britain and Ireland Language English Subject Natural selection Evolutionary biology Published 24 November 1859 (John Murray) Media type Print (Hardback) Pages 502 OCLC 352242 Preceded by On the Tendency of Species to form Varieties; and on the Perpetuation of Varieties and Species by Natural Means of Selection Followed by Fertilisation of Orchids
Document 9: Evolutionary history of plants: Evidence for the appearance of the first land plants occurs in the Ordovician, around 450 million years ago, in the form of fossil spores. Land plants began to diversify in the Late Silurian, from around 430 million years ago, and the results of their diversification are displayed in remarkable detail in an early Devonian fossil assemblage from the Rhynie chert. This chert, formed in volcanic hot springs, preserved several species of early plants in cellular detail by petrification.
Document 10: Flowering plant: The evolution of seed plants and later angiosperms appears to be the result of two distinct rounds of whole genome duplication events. These occurred at 319 million years ago and 192 million years ago. Another possible whole genome duplication event at 160 million years ago perhaps created the ancestral line that led to all modern flowering plants. That event was studied by sequencing the genome of an ancient flowering plant, Amborella trichopoda, and directly addresses Darwin's "abominable mystery."
Document 11: The Effects of Cross and Self Fertilisation in the Vegetable Kingdom: The Effects of Cross and Self Fertilisation in the Vegetable Kingdom is a book on evolution in plants by Charles Darwin, first published in 1876. In this book Darwin examines the effects of cross and self fertilisation of plants and provides experimental evidence for a hypothesis stated in his famed book of 1859, Origin of Species, that "... in none [i.e. plant] [...]can self-fertilisation go on for perpetuity" ("Origin", p. 101). He reports on experiments conducted on over 60 different species of plants, where he used controlled pollinations in order to produce self-fertilised and cross-fertilised descendants. Through growth experiments of this progeny, he concluded that self-fertilised progeny performed poorer in most species and for most traits measured. Thus he showed that inbreeding may have severe detrimental effects on progeny. While this idea was accepted by many, e.g. plant and animal breeders, Darwin's book provided overwhelming experimental support for this idea. This book has remained the starting point for the study of inbreeding and is cited in scientific papers to this effect to this day.
Document 12: On the Origin of Species: Darwin had his basic theory of natural selection "by which to work" by December 1838, yet almost twenty years later, when Wallace's letter arrived on 18 June 1858, Darwin was still not ready to publish his theory. It was long thought that Darwin avoided or delayed making his ideas public for personal reasons. Reasons suggested have included fear of religious persecution or social disgrace if his views were revealed, and concern about upsetting his clergymen naturalist friends or his pious wife Emma. Charles Darwin's illness caused repeated delays. His paper on Glen Roy had proved embarrassingly wrong, and he may have wanted to be sure he was correct. David Quammen has suggested all these factors may have contributed, and notes Darwin's large output of books and busy family life during that time.
Document 13: Darwin from Orchids to Variation: Between 1860 and 1868, the life and work of Charles Darwin from "Orchids" to "Variation" continued with research and experimentation on evolution, carrying out tedious work to provide evidence of the extent of natural variation enabling artificial selection. He was repeatedly held up by his illness, and continued to find relaxation and interest in the study of plants. His studies of insect pollination led to publication of his book "Fertilisation of Orchids" as his first detailed demonstration of the power of natural selection, explaining the complex ecological relationships and making testable predictions. As his health declined, he lay on his sickbed in a room filled with inventive experiments to trace the movements of climbing plants.
Document 14: Flowering plant: The great angiosperm radiation, when a great diversity of angiosperms appears in the fossil record, occurred in the mid-Cretaceous (approximately 100 million years ago). However, a study in 2007 estimated that the division of the five most recent (the genus Ceratophyllum, the family Chloranthaceae, the eudicots, the magnoliids, and the monocots) of the eight main groups occurred around 140 million years ago. By the late Cretaceous, angiosperms appear to have dominated environments formerly occupied by ferns and cycadophytes, but large canopy-forming trees replaced conifers as the dominant trees only close to the end of the Cretaceous 66 million years ago or even later, at the beginning of the Tertiary. The radiation of herbaceous angiosperms occurred much later. Yet, many fossil plants recognizable as belonging to modern families (including beech, oak, maple, and magnolia) had already appeared by the late Cretaceous.
Document 15: On the Origin of Species: On the Origin of Species (or, more completely, On the Origin of Species by Means of Natural Selection, or the Preservation of Favoured Races in the Struggle for Life), published on 24 November 1859, is a work of scientific literature by Charles Darwin which is considered to be the foundation of evolutionary biology. Darwin's book introduced the scientific theory that populations evolve over the course of generations through a process of natural selection. It presented a body of evidence that the diversity of life arose by common descent through a branching pattern of evolution. Darwin included evidence that he had gathered on the "Beagle" expedition in the 1830s and his subsequent findings from research, correspondence, and experimentation.
ground_truth: Charles Darwin
sub_queries: Who coined the term "abominable mystery"? Answer: Darwin
Darwin from Orchids to Variation >> main subject Answer: Charles Darwin