A theoretical evolutionary sequence for hierarchical human societies

2021 ◽  
Author(s):  
Ian Walters
Keyword(s):  
Evolutionary Sequence

scholarly journals The Origin of Absorption Spectra in Quasi-Stellar Objects

1980 ◽  
Vol 92 ◽  
pp. 107-117 ◽  
Author(s):  
Ray J. Weymann
Keyword(s):  
Absorption Line ◽  
Absorption Spectra ◽  
Classification Scheme ◽  
Spectral Characteristics ◽  
Type A ◽  
Galactic Halos ◽  
Evolutionary Sequence ◽  
Rich Cluster ◽  
Stellar Objects ◽  
Quasi Stellar Objects

A classification scheme for QSO absorption line spectra is described which ascribes the origin of the lines to at least four mechanisms: (A) Explosive ejection of material at speeds up to 0.1 c. (B) Absorption by highly ionized material moving in a rich cluster in which the QSO is embedded. (C-1) Cosmologically distant intervening material with ‘normal’ abundances, probably associated with large galactic halos. (C-2) Cosmologically distant intervening material consisting of primordial uncondensed gas. Examples of each type of spectra are given and their ionization and other spectral characteristics discussed. The similarity between the development of novae spectra and a possible evolutionary sequence of the explosive ejecta of type A is striking and suggestive. Several difficulties and unsolved problems involving this scheme are noted. Finally, we speculate on the interpretation of two interesting objects (PKS 0237-23 and the ‘twin quasars’ 0957+56A,B) in the context of this scheme.

scholarly journals Ecological traits and evolutionary sequence of nest establishment in fungus-growing ants (Hymenoptera, Formicidae, Attini)

2004 ◽  
Vol 81 (1) ◽  
pp. 39-48 ◽  
Author(s):  
H. FERNÁNDEZ-MARÍN ◽  
J. K. ZIMMERMAN ◽  
W. T. WCISLO
Keyword(s):  
Evolutionary Sequence ◽  
Ecological Traits ◽  
Fungus Growing Ants

Chromosomal Mechanisms in the Evolution of Artiodactyls

Paleobiology ◽  
1975 ◽  
Vol 1 (2) ◽  
pp. 175-188 ◽  
Author(s):  
Neil B. Todd
Keyword(s):  
X Chromosome ◽  
Fossil Record ◽  
Diploid Number ◽  
Evolutionary Sequence ◽  
Extant Species ◽  
Adaptive Radiations ◽  
The Times

Evidence is presented that primitive artiodactyls had a diploid number of 14. The higher diploid numbers of most living artiodactyls are interpreted as resulting from karyotypic fissioning at the times of past adaptive radiations. The fossil record appears to support this contention.An evolutionary sequence of unusual X chromosome transformations has been deduced from the differences that exist among extant species. From these, and from interrelationships of karyotypes, certain phylogenetic revisions are suggested.

scholarly journals An evolutionary sequence of expanding hydrogen shells in galaxy discs

2007 ◽  
Vol 467 (3) ◽  
pp. 1117-1123 ◽  
Author(s):  
M. Relaño ◽  
J. E. Beckman ◽  
O. Daigle ◽  
C. Carignan
Keyword(s):  
Evolutionary Sequence

Forty-five years of change on low wooded islands, Great Barrier Reef

1978 ◽  
Vol 284 (999) ◽  
pp. 63-80 ◽  
Keyword(s):  
Great Barrier Reef ◽  
Coral Growth ◽  
Barrier Reef ◽  
Evolutionary Sequence ◽  
The Holocene ◽  
Additional Information ◽  
Aerial Reconnaissance ◽  
History Of ◽  
Barrier Reefs

During the 1928-29 Expedition, centred at Low Isles, Spender mapped the ‘low wooded islands’ or ‘island-reefs’ of Low Isles and Three Isles in detail, and additional information was published by Steers, T. A. Stephenson and others. From this work, two different models of the evolution of low wooded islands were proposed, Spender holding that the islands were in a state of equilibrium resulting from their location on the reef, Steers that they could be placed in an evolutionary sequence. Moorhouse described the results of cyclones at Low Isles in 1931 and 1934, and Fairbridge & Teichert reconsidered the general issues following aerial reconnaissance and a brief visit to Low Isles in 1945. Subsequently, aspects of change since 1928-29 have been studied at Low Isles by W. Stephenson, Endean & Bennett in 1954 and by W. Macnae in 1965. Maps produced since 1929, however, have all been based on Spender’s surveys. In 1973, Low Isles and Three Isles were remapped in detail, and a direct comparison can now be made over an interval of 45 years. This shows changes in island topography, and substantial alteration in the size and location of shingle ramparts which has affected conditions for coral growth on reef flats. Mangroves have extended greatly at Low Isles, but not at all at Three Isles. The implications of these findings for the general models of Steers and Spender will be discussed and related to the Holocene history of the Great Barrier Reefs.

Interstellar Ethics and the Goldilocks Evolutionary Sequence: Can We Expect ETI to Be Moral?

2021 ◽  
pp. 339-359
Author(s):  
Margaret Boone Rappaport ◽  
Christopher Corbally ◽  
Konrad Szocik
Keyword(s):  
Evolutionary Sequence

scholarly journals The Ionization of Planetary Nebulae

1968 ◽  
Vol 34 ◽  
pp. 190-204 ◽  
Author(s):  
Robert E. Williams
Keyword(s):  
Ionizing Radiation ◽  
Emission Line ◽  
Radiation Field ◽  
Planetary Nebulae ◽  
Model Atmosphere ◽  
Evolutionary Sequence ◽  
Lyman Continuum ◽  
The Mean ◽  
Central Stars

The ionization of the most abundant elements in planetary nebulae has been determined for a number of models of nebulae at different epochs in their expansion. The values used for the temperatures and radii of the central stars and the sizes and densities of the shells have come from Seaton's evolutionary sequence. The ionizing radiation field has been taken from model atmosphere calculations of the central stars by Gebbie and Seaton, and Böhm and Deinzer. Emission-line fluxes have been calculated for the models and compared with observations of planetary nebulae by O'Dell, Osterbrock's group, and Aller and his collaborators. Results indicate that the central stars have strong He+ Lyman continuum excesses, similar to those predicted by Gebbie and Seaton. The mean abundance determinations for the nebulae made by Aller are confirmed, with the exception of nitrogen, which appears to be 3 or 4 times more abundant than his value. It is also seen that the electron temperatures of the nebulae are higher than previous theoretical determinations, providing better agreement with empirically derived values.

scholarly journals Neutral Hydrogen Mapping of three SO Galaxies

1983 ◽  
Vol 100 ◽  
pp. 105-106
Author(s):  
W. W. Shane ◽  
N. Krumm
Keyword(s):  
Neutral Hydrogen ◽  
Evolutionary Sequence

Synthesis maps of HI in three SO galaxies are discussed. In one case several companions are observed. An evolutionary sequence based on accretion is suggested.

scholarly journals Born-again AGB stars: Starting point of the H-deficient post-AGB evolutionary sequence?

1999 ◽  
Vol 191 ◽  
pp. 493-498 ◽  
Author(s):  
K. Werner ◽  
S. Dreizler ◽  
T. Rauch ◽  
L. Koesterke ◽  
U. Heber
Keyword(s):  
Planetary Nebulae ◽  
Agb Stars ◽  
Evolutionary Sequence ◽  
Starting Point ◽  
Born Again

We discuss the origin of hot hydrogen-deficient post-AGB stars. Evidence is growing that the “born-again AGB star scenario” as a consequence of a late He shell flash cannot explain the diverse observations. Analyses of the stars and their associated planetary nebulae suggest that the H-deficiency is not formed during the second post-AGB phase but already while the star is still on the AGB. There are even hints that the H-deficiency can occur before the first departure from the AGB.

scholarly journals Circumstellar dust shells around WN10-11 and WC8-10 stars: An evolutionary sequence?∗

1984 ◽  
Vol 105 ◽  
pp. 273-277
Author(s):  
K.A. van der Hucht ◽  
P.M. Williams ◽  
P.S. Thé
Keyword(s):  
Circumstellar Dust ◽  
Evolutionary Sequence ◽  
Late Type ◽  
Dust Shells ◽  
Density Distributions

In a recent IR photometric survey of late-type WC and WN stars, it was discovered that not only most WC8-10 stars have circumstellar dust shells, but that two extreme late-type WN stars also have strong IR excesses from circumstellar dust. The latter shells appear to have significantly different density distributions. In this paper the possibility of an evolutionary sequence is suggested.

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