scholarly journals Was Charles Darwin right in his explanation of the ‘abominable mystery’?

2018 ◽  
Vol 5 ◽  
pp. 25-30
Author(s):  
Sergio Sgorbati ◽  
Marco D'Antraccoli ◽  
Sandra Citterio ◽  
Rodolfo Gentili ◽  
Lorenzo Peruzzi
Keyword(s):  
Pacific Islands ◽  
Charles Darwin ◽  
Flowering Plants ◽  
Molecular Clocks ◽  
Rapid Radiation ◽  
Sw Pacific ◽  
Origin Of Angiosperms ◽  
Fossil Records ◽  
Time Of Origin

The site and time of origin of angiosperms are still debated. The co-occurrence of many of the early branching lineages of flowering plants in a region somewhere between Australia and the SW Pacific islands suggests a possible Gondwanan origin of angiosperms. The recent recognition of Zealandia, a 94% submerged continent in the east of Australia, could explain the discrepancy between molecular clocks and fossil records about the age of angiosperms, supporting the old Darwinian hypothesis of a “lost continent” to explain the “abominable mystery” regarding the origin and rapid radiation of flowering plants.

scholarly journals Was Charles Darwin right in his explanation of the ‘abominable mystery’?

2018 ◽  
Vol 5 ◽  
pp. 25-30
Author(s):  
Sergio Sgorbati ◽  
Marco D'Antraccoli ◽  
Sandra Citterio ◽  
Rodolfo Gentili ◽  
Lorenzo Peruzzi
Keyword(s):  
Pacific Islands ◽  
Charles Darwin ◽  
Flowering Plants ◽  
Molecular Clocks ◽  
Rapid Radiation ◽  
Sw Pacific ◽  
Origin Of Angiosperms ◽  
Fossil Records ◽  
Time Of Origin

The site and time of origin of angiosperms are still debated. The co-occurrence of many of the early branching lineages of flowering plants in a region somewhere between Australia and the SW Pacific islands suggests a possible Gondwanan origin of angiosperms. The recent recognition of Zealandia, a 94% submerged continent in the east of Australia, could explain the discrepancy between molecular clocks and fossil records about the age of angiosperms, supporting the old Darwinian hypothesis of a “lost continent” to explain the “abominable mystery” regarding the origin and rapid radiation of flowering plants.

scholarly journals Molecular clocks and the early evolution of metazoan nervous systems

2015 ◽  
Vol 370 (1684) ◽  
pp. 20150046 ◽  
Author(s):  
Gregory A. Wray
Keyword(s):  
Sensory Processing ◽  
Fossil Record ◽  
Sequence Data ◽  
Divergence Times ◽  
Molecular Clocks ◽  
Sense Organs ◽  
Animal Evolution ◽  
Nervous Systems ◽  
Nervous System Evolution ◽  
Fossil Records

The timing of early animal evolution remains poorly resolved, yet remains critical for understanding nervous system evolution. Methods for estimating divergence times from sequence data have improved considerably, providing a more refined understanding of key divergences. The best molecular estimates point to the origin of metazoans and bilaterians tens to hundreds of millions of years earlier than their first appearances in the fossil record. Both the molecular and fossil records are compatible, however, with the possibility of tiny, unskeletonized, low energy budget animals during the Proterozoic that had planktonic, benthic, or meiofaunal lifestyles. Such animals would likely have had relatively simple nervous systems equipped primarily to detect food, avoid inhospitable environments and locate mates. The appearance of the first macropredators during the Cambrian would have changed the selective landscape dramatically, likely driving the evolution of complex sense organs, sophisticated sensory processing systems, and diverse effector systems involved in capturing prey and avoiding predation.

Islands of Discovery: Scientific Curiosity in the Works of Darwin, Huxley and Wells

Dark Paradise ◽  
2016 ◽  
Author(s):  
Jennifer Fuller
Keyword(s):  
Science Fiction ◽  
Pacific Islands ◽  
Charles Darwin ◽  
Thomas Henry Huxley ◽  
Scientific Curiosity ◽  
Unknown Species ◽  
The Pacific ◽  
New Ideas ◽  
Theories Of Evolution ◽  
Descent Of Man

Intrigued by the descriptions of hitherto unknown species, Victorian naturalists embarked on Pacific journeys to study new flora and fauna. The third chapter follows a young Charles Darwin and Thomas Henry Huxley as they develop theories that would challenge the assumed boundaries between “civilized” and “savage” man. Their often overlooked travel narratives, The Voyage of the Beagleand The Voyage of the Rattlesnake respectively, displayed not only emerging theories of evolution and natural selection, but also early biological and anthropological observations that questioned whether Pacific islanders were truly so different from British ones. These radical new ideas, spurred on by later works such as Origin of the Species and The Descent of Man, influenced novelists to use the Pacific islands as a testing ground for new theories of regressive evolution. Capitalizing on the emerging genre of “science fiction,” H.G. Wells imagined the Pacific in The Island of Doctor Moreau not as an idyllic paradise but as a horrific nightmare that reduced all islanders, British and native, to their most bestial forms displaying distinctly Pacific resonances and the changing British perspectives on the islands.

scholarly journals Micro-caddisfly faunas of Australia and the southwest Pacific (Trichoptera, Hydroptilidae)

Zoosymposia ◽  
2016 ◽  
Vol 10 (1) ◽  
pp. 439-450
Author(s):  
ALICE WELLS ◽  
KJELL ARNE JOHANSON
Keyword(s):  
New Zealand ◽  
Pacific Islands ◽  
New Caledonia ◽  
New Guinea ◽  
Faunal Composition ◽  
Southwest Pacific ◽  
Sw Pacific ◽  
Chance Events ◽  
Corroborative Evidence

Today's distributions of faunal groups reflect historic events—geological and evolutionary, as well as dispersals, extinctions and chance events. The extent to which each of these contributed to the hydroptilid faunas of mainland Australia, Tasmania, New Guinea, New Zealand, New Caledonia, Fiji and Vanuatu is explored by comparison of the faunal composition, geology and geography of Australia and these SW Pacific islands. Corroborative evidence is sought from other groups, flora as well as fauna.

Does the fossil record of spiders track that of their principal prey, the insects?

2003 ◽  
Vol 94 (3) ◽  
pp. 275-281 ◽  
Author(s):  
David Penney
Keyword(s):  
Fossil Record ◽  
Geological Time ◽  
Rates Of Change ◽  
Exponential Increase ◽  
The Family ◽  
Family Level ◽  
Origin Of Angiosperms ◽  
Fossil Records ◽  
Insect Family ◽  
Over Time

ABSTRACTThe currently accepted cladogram of spider phylogeny and palaeontological data are used to evaluate spider family richness through geological time. A significantly more diverse spider fossil record is predicted than observed. The predicted rate of spider family diversification is considered more accurate because of its close similarity at 0 Ma to the number of extant families. Predicted spider family palaeodiversity is compared with insect family palaeodiversity to investigate whether spiders track insects through geological time. At the family level, the insects, and observed and predicted spider fossil records show an exponential increase over time, the pattern typical of a radiating group. No significant differences are observed in the rates of change in the slopes, and hence rate of diversification of spiders and insects over time. This suggests that spiders probably co-radiated alongside the insects, with the major radiations of both groups occurring at least 100 Ma before the origin of angiosperms.

scholarly journals The Ediacaran emergence of bilaterians: congruence between the genetic and the geological fossil records

2008 ◽  
Vol 363 (1496) ◽  
pp. 1435-1443 ◽  
Author(s):  
Kevin J Peterson ◽  
James A Cotton ◽  
James G Gehling ◽  
Davide Pisani
Keyword(s):  
Molecular Clock ◽  
Cambrian Explosion ◽  
Divergence Times ◽  
Molecular Clocks ◽  
Historical Records ◽  
Calibration Point ◽  
Geological Time ◽  
Fossil Records

Unravelling the timing of the metazoan radiation is crucial for elucidating the macroevolutionary processes associated with the Cambrian explosion. Because estimates of metazoan divergence times derived from molecular clocks range from quite shallow (Ediacaran) to very deep (Mesoproterozoic), it has been difficult to ascertain whether there is concordance or quite dramatic discordance between the genetic and geological fossil records. Here, we show using a range of molecular clock methods that the major pulse of metazoan divergence times was during the Ediacaran, which is consistent with a synoptic reading of the Ediacaran macrobiota. These estimates are robust to changes in priors, and are returned with or without the inclusion of a palaeontologically derived maximal calibration point. Therefore, the two historical records of life both suggest that although the cradle of Metazoa lies in the Cryogenian, and despite the explosion of ecology that occurs in the Cambrian, it is the emergence of bilaterian taxa in the Ediacaran that sets the tempo and mode of macroevolution for the remainder of geological time.

scholarly journals A duplicate gene rooting of seed plants and the phylogenetic position of flowering plants

2010 ◽  
Vol 365 (1539) ◽  
pp. 383-395 ◽  
Author(s):  
Sarah Mathews ◽  
Mark D. Clements ◽  
Mark A. Beilstein
Keyword(s):  
Sequence Data ◽  
Duplicate Gene ◽  
Molecular Data ◽  
Flowering Plants ◽  
Phylogenetic Position ◽  
Molecular Evidence ◽  
Dna Sequence Data ◽  
Extant Species ◽  
Statistical Support ◽  
Origin Of Angiosperms

Flowering plants represent the most significant branch in the tree of land plants, with respect to the number of extant species, their impact on the shaping of modern ecosystems and their economic importance. However, unlike so many persistent phylogenetic problems that have yielded to insights from DNA sequence data, the mystery surrounding the origin of angiosperms has deepened with the advent and advance of molecular systematics. Strong statistical support for competing hypotheses and recent novel trees from molecular data suggest that the accuracy of current molecular trees requires further testing. Analyses of phytochrome amino acids using a duplicate gene-rooting approach yield trees that unite cycads and angiosperms in a clade that is sister to a clade in which Gingko and Cupressophyta are successive sister taxa to gnetophytes plus Pinaceae. Application of a cycads + angiosperms backbone constraint in analyses of a morphological dataset yields better resolved trees than do analyses in which extant gymnosperms are forced to be monophyletic. The results have implications both for our assessment of uncertainty in trees from sequence data and for our use of molecular constraints as a way to integrate insights from morphological and molecular evidence.

scholarly journals Survival and selection biases in early animal evolution and a source of systematic overestimation in molecular clocks

2019 ◽  
Author(s):  
Graham Budd ◽  
Richard P. Mann
Keyword(s):  
Fossil Record ◽  
Null Hypothesis ◽  
Cambrian Explosion ◽  
Molecular Clocks ◽  
Statistical Structure ◽  
Animal Evolution ◽  
Evolutionary Radiation ◽  
Large Groups ◽  
Time Of Origin ◽  
Looking Back

Important evolutionary events such as the Cambrian Explosion have inspired many attempts at explanation: why do they happen when they do? What shapes them, and why do they eventually come to an end? However, much less attention has been paid to the idea of a “null hypothesis” – that certain features of such diversifications arise simply through their statistical structure. Looking back from our own perspective to the origins of large groups such as the arthropods, or even the animals themselves, will expose features that look causal but are in fact inevitable. Here we review these features with particular regard to the Cambrian explosion. We conclude that the fossil record of the late Ediacaran to Cambrian is very likely to be recording a true evolutionary radiation at this time; and show how the unusually rapid nature of this event leads to characteristic over-estimation of its time of origin by molecular clock methods - an artefact that is likely to apply to other unusually fast radiations too.

scholarly journals Neogene amphibians and reptiles (Caudata, Anura, Gekkota, Lacertilia, and Testudines) from the south of Western Siberia, Russia, and Northeastern Kazakhstan

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3025 ◽  
Author(s):  
Davit Vasilyan ◽  
Vladimir S. Zazhigin ◽  
Madelaine Böhme
Keyword(s):  
Middle Miocene ◽  
Western Siberia ◽  
Rana Temporaria ◽  
Bufo Bufo ◽  
Climatic Conditions ◽  
Early Pleistocene ◽  
Molecular Clocks ◽  
Fossil Remains ◽  
Western Asia ◽  
Fossil Records

BackgroundThe present-day amphibian and reptile fauna of Western Siberia are the least diverse of the Palaearctic Realm, as a consequence of the unfavourable climatic conditions that predominate in this region. The origin and emergence of these herpetofaunal groups are poorly understood. Aside from the better-explored European Neogene localities yielding amphibian and reptile fossil remains, the Neogene herpetofauna of Western Asia is understudied. The few available data need critical reviews and new interpretations, taking into account the more recent records of the European herpetofauna. The comparison of this previous data with that of European fossil records would provide data on palaeobiogeographic affiliations of the region as well as on the origin and emergence of the present-day fauna of Western Siberia. An overview of the earliest occurrences of certain amphibian lineages is still needed. In addition, studies that address such knowledge gaps can be useful for molecular biologists in their calibration of molecular clocks.Methods and ResultsIn this study, we considered critically reviewed available data from amphibian and reptile fauna from over 40 Western Siberian, Russian and Northeastern Kazakhstan localities, ranging from the Middle Miocene to Early Pleistocene. Herein, we provided new interpretations that arose from our assessment of the previously published and new data. More than 50 amphibians and reptile taxa were identified belonging to families Hynobiidae, Cryptobranchidae, Salamandridae, Palaeobatrachidae, Bombinatoridae, Pelobatidae, Hylidae, Bufonidae, Ranidae, Gekkonidae, Lacertidae, and Emydidae. Palaeobiogeographic analyses were performed for these groups and palaeoprecipitation values were estimated for 12 localities, using the bioclimatic analysis of herpetofaunal assemblages.ConclusionThe Neogene assemblage of Western Siberia was found to be dominated by groups of European affinities, such as Palaeobatrachidae,Bombina, Hyla,Bufo bufo, and a small part of this assemblage included Eastern Palaearctic taxa (e.g.Salamandrella,Tylototriton,Bufotes viridis). For several taxa (e.g.Mioproteus, Hyla, Bombina,Rana temporaria), the Western Siberian occurrences represented their most eastern Eurasian records. The most diverse collection of fossil remains was found in the Middle Miocene. Less diversity has been registered towards the Early Pleistocene, potentially due to the progressive cooling of the climate in the Northern Hemisphere. The results of our study showed higher-amplitude changes of precipitation development in Western Siberia from the Early Miocene to the Pliocene, than previously assumed.

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