scholarly journals Premature rejection in science: The case of the Younger Dryas Impact Hypothesis

2022 ◽  
Vol 105 (1) ◽  
pp. 003685042110642
Author(s):  
James Lawrence Powell
Keyword(s):  
Continental Drift ◽  
Younger Dryas ◽  
Western Hemisphere ◽  
First Century ◽  
Meteorite Impact ◽  
Substantial Evidence ◽  
Indian Culture ◽  
Impact Cratering ◽  
Cool Period ◽  
Impact Hypothesis

The progress of science has sometimes been unjustifiably delayed by the premature rejection of a hypothesis for which substantial evidence existed and which later achieved consensus. Continental drift, meteorite impact cratering, and anthropogenic global warming are examples from the first half of the twentieth century. This article presents evidence that the Younger Dryas Impact Hypothesis (YDIH) is a twenty-first century case. The hypothesis proposes that the airburst or impact of a comet ∼12,850 years ago caused the ensuing ∼1200-year-long Younger Dryas (YD) cool period and contributed to the extinction of the Pleistocene megafauna in the Western Hemisphere and the disappearance of the Clovis Paleo-Indian culture. Soon after publication, a few scientists reported that they were unable to replicate the critical evidence and the scientific community at large came to reject the hypothesis. By today, however, many independent studies have reproduced that evidence at dozens of YD sites. This article examines why scientists so readily accepted the early false claims of irreproducibility and what lessons the premature rejection of the YDIH holds for science.

Introduction

2018 ◽  
pp. 1-7
Author(s):  
Albert C. Goodyear ◽  
Christopher R. Moore
Keyword(s):  
Sea Level ◽  
Late Pleistocene ◽  
Coastal Plain ◽  
Younger Dryas ◽  
Archaeological Sites ◽  
Impact Hypothesis

This chapter reviews the significant features of early prehistoric occupations of the Southeastern U.S. Coastal Plain. Along with the Pleistocene age archaeological sites, salient aspects of the geology, including sea level positions, are presented. Possible Pre-Clovis sites dating from pre-LGM to late Pleistocene times are considered. Clovis is seen to have a Coastal Plain settlement focus that includes the now-drowned shelf. The dramatic onset of the Younger Dryas and its potential effects on people, including the “Younger Dryas Impact Hypothesis,” are reviewed.

scholarly journals Julius Kaljuvee, Ivan Reinwald, and Estonian pioneering ideas on meteorite impacts and cosmic neocatastrophism in the early 20th century

2018 ◽  
Vol 189 (3) ◽  
pp. 11 ◽  
Author(s):  
Grzegorz Racki ◽  
Tõnu Viik ◽  
Väino Puura
Keyword(s):  
Large Body ◽  
Rare Event ◽  
Continental Drift ◽  
Meteorite Impact ◽  
Mining Engineer ◽  
Meteorite Impacts ◽  
Event Theory ◽  
Geological Past ◽  
The Impact ◽  
Impact Origin

The article comprehensively presents little known Estonian contribution to the recognition of first meteorite impact structures in Europe, related to works of Julius Kaljuvee (Kalkun; 1869–1940) and Ivan Reinwald (Reinwaldt; 1878–1941). As an active educator specialized in geoscience, Kaljuvee was the first to hypothesize in 1922 that Kaali lake cirque in Saaremaa Island, Estonia, was created by meteorite impact. Thanks to mining engineer Reinwald, this assumption was accepted since 1928 due to the exhaustive field and borehole works of the latter (also as a result of exploration by several German scholars, including renowned Alfred Wegener). The impact origin of Kaali structure was proved finally in 1937 by finding of meteoritic iron splinters (as the first European site). Reinwald was not only outstanding investigator of meteorite cratering process, but also successful propagator of the Estonian discoveries in Anglophone mainstream science in 1930s. In addition, in his 1933 book, Kaljuvee first highlighted an impact explanation of enigmatic Ries structure in Bavaria, as well as probable magmatic activation in distant regions due to “the impulse of a giant meteorite”. He also outlined ideas of the inevitable periodic cosmic collisions in geological past (“rare event” theory nowadays), and resulting biotic crises. In a general conceptual context, the ideas of Kaljuvee were in noteworthy direct or indirect link with concepts of the great French naturalists – Laplace, Cuvier and Élie de Beaumont. However, some other Kaljuvee’s notions, albeit recurrent also later in geoscientific literature, are queer at the present time (e.g., the large-body impact as a driving force of continental drift and change the Earth axis, resulting in the Pleistocene glaciation). Thus, the Kaljuvee thought-provocative but premature dissertation is rather a record of distinguishing erudite activity, but not a real neocatastrophic landmark in geosciences history. Nevertheless, several concepts of Kaljuvee were revived as the key elements in the current geological paradigm.

scholarly journals Independent evaluation of conflicting microspherule results from different investigations of the Younger Dryas impact hypothesis

2012 ◽  
Vol 109 (44) ◽  
pp. E2960-E2969 ◽  
Author(s):  
M. A. LeCompte ◽  
A. C. Goodyear ◽  
M. N. Demitroff ◽  
D. Batchelor ◽  
E. K. Vogel ◽  
...  
Keyword(s):  
Younger Dryas ◽  
Independent Evaluation ◽  
Impact Hypothesis

Environmental and biotic change at the nanodiamond datum: The Younger Dryas boundary impact hypothesis

2013 ◽  
Vol 310 ◽  
pp. 234
Author(s):  
James Kennett ◽  
Allen West ◽  
Douglas Kennett ◽  
Charles Kinzie ◽  
Wendy Wolbach
Keyword(s):  
Younger Dryas ◽  
Biotic Change ◽  
Impact Hypothesis

scholarly journals Bayesian chronological analyses consistent with synchronous age of 12,835–12,735 Cal B.P. for Younger Dryas boundary on four continents

2015 ◽  
Vol 112 (32) ◽  
pp. E4344-E4353 ◽  
Author(s):  
James P. Kennett ◽  
Douglas J. Kennett ◽  
Brendan J. Culleton ◽  
J. Emili Aura Tortosa ◽  
James L. Bischoff ◽  
...  
Keyword(s):  
Statistical Tests ◽  
Younger Dryas ◽  
Greenland Ice Sheet ◽  
Causal Connection ◽  
Impact Event ◽  
Widespread Distribution ◽  
Proxy Records ◽  
Melt Glass ◽  
Age Range ◽  
Impact Hypothesis

The Younger Dryas impact hypothesis posits that a cosmic impact across much of the Northern Hemisphere deposited the Younger Dryas boundary (YDB) layer, containing peak abundances in a variable assemblage of proxies, including magnetic and glassy impact-related spherules, high-temperature minerals and melt glass, nanodiamonds, carbon spherules, aciniform carbon, platinum, and osmium. Bayesian chronological modeling was applied to 354 dates from 23 stratigraphic sections in 12 countries on four continents to establish a modeled YDB age range for this event of 12,835–12,735 Cal B.P. at 95% probability. This range overlaps that of a peak in extraterrestrial platinum in the Greenland Ice Sheet and of the earliest age of the Younger Dryas climate episode in six proxy records, suggesting a causal connection between the YDB impact event and the Younger Dryas. Two statistical tests indicate that both modeled and unmodeled ages in the 30 records are consistent with synchronous deposition of the YDB layer within the limits of dating uncertainty (∼100 y). The widespread distribution of the YDB layer suggests that it may serve as a datum layer.

scholarly journals Reply to Holliday and Boslough et al.: Synchroneity of widespread Bayesian-modeled ages supports Younger Dryas impact hypothesis

2015 ◽  
Vol 112 (49) ◽  
pp. E6723-E6724 ◽  
Author(s):  
James P. Kennett ◽  
Douglas J. Kennett ◽  
Brendan J. Culleton ◽  
J. Emili Aura Tortosa ◽  
Ted E. Bunch ◽  
...  
Keyword(s):  
Younger Dryas ◽  
Impact Hypothesis

Potential Consequences of the YDB Cosmic Impact at 12.8 kya

2018 ◽  
pp. 175-192 ◽  
Author(s):  
James P. Kennett ◽  
Douglas J. Kennett ◽  
Malcolm A. LeCompte ◽  
Allen West
Keyword(s):  
Northern Hemisphere ◽  
Explanatory Power ◽  
Younger Dryas ◽  
Cultural Changes ◽  
Impact Hypothesis

The Younger Dryas cooling episode came about in the Northern Hemisphere in an abrupt manner atypical of deglaciation events. This cooling resulted in the Pleistocene extinctions of many genera of faunas and coincided with the disappearance of the Clovis culture. The Younger Dryas Cosmic Impact of 12.8 kya is then considered as a hypothesis that explains these dramatic and enigmatic events. As a nonlinear climate episode, the YDB Impact Hypothesis can have explanatory power in accounting for the associated environmental and cultural changes.

Deglacial Hydroclimate of Midcontinental North America

2015 ◽  
Vol 83 (2) ◽  
pp. 336-344 ◽  
Author(s):  
Steven L. Voelker ◽  
Michael C. Stambaugh ◽  
Richard P. Guyette ◽  
Xiahong Feng ◽  
David A. Grimley ◽  
...  
Keyword(s):  
High Pressure ◽  
North America ◽  
Mechanistic Model ◽  
Ice Sheet ◽  
Younger Dryas ◽  
Early Holocene ◽  
Pressure System ◽  
Cool Period ◽  
High Pressure System ◽  
Last Deglacial

During the last deglaciation temperatures over midcontinental North America warmed dramatically through the Bølling-Allerød, underwent a cool period associated with the Younger-Dryas and then reverted to warmer, near modern temperatures during the early Holocene. However, paleo proxy records of the hydroclimate of this period have presented divergent evidence. We reconstruct summer relative humidity (RH) across the last deglacial period using a mechanistic model of cellulose and leaf water δ18O and δD combined with a pollen-based temperature proxy to interpret stable isotopes of sub-fossil wood. Midcontinental RH was similar to modern conditions during the Last Glacial Maximum, progressively increased during the Bølling-Allerød, peaked during the Younger-Dryas, and declined sharply during the early Holocene. This RH record suggests deglacial summers were cooler and characterized by greater advection of moisture-laden air-masses from the Gulf of Mexico and subsequent entrainment over the mid-continent by a high-pressure system over the Laurentide ice sheet. These patterns help explain the formation of dark-colored cumulic horizons in many Great Plains paleosol sequences and the development of no-analog vegetation types common to the Midwest during the last deglacial period. Likewise, reduced early Holocene RH and precipitation correspond with a diminished glacial high-pressure system during the latter stages of ice-sheet collapse.

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