Nor, considered aright, does it seem any argument in favor of the gradual extinction
of the Sperm Whale, for example, that in former years (the latter part of the last century, say) these Leviathans, in small pods, were encountered much oftener than at present, and, in consequence, the voyages were not so prolonged, and were also much more remunerative.
The lower middle class, the small manufacturer, the shopkeeper, the artisan, the peasant, all these fight against the bourgeoisie, to save from extinction
their existence as fractions of the middle class.
Either must he attain the treasure--for so ran the inexorable logic of the shadow-land of the unconscious--or else sink into the all- devouring sea, the blackness eater of the light that swallowed to extinction the sun each night .
Otherwise he would ooze down through the shadow-realm of the unconscious into the all- darkness of extinction.
The volcanic emissions would have caused extreme environmental changes, leading to the animal extinctions
In any event, worldwide extinctions
of major groups of organisms, while extremely interesting and significant, play only a limited role in biostratigraphy because these major extinctions
provide only a few correlation horizons.
So the 60-meter gap between the zircons and fossils may have formed over a much longer period of time, and the Dicynodon die-off may have coincided with the marine extinctions
The five previous major extinctions
stemmed from a variety of origins, from volcanic explosions to the impact of huge asteroids.
Since complex life evolved, about a half billion years ago, there have been five major mass extinctions
called the Big Five (see below).
It reviews various topics in extinction
research and the social, political, and economic implications of findings for both ancient extinctions
and the modern biodiversity crisis.
This paper explores recent scholarship regarding the relationship between climatological and anthropogenic factors in late Quaternary megafaunal extinctions
, examines these findings in light of ongoing adherence to the theory of Pleistocene overkill, seeks to understand the relevance of these issues in a world historical context, and argues for the integration of ongoing scientific discoveries into historical narratives.
We have shown that these events are synchronous to within a gnat's eyebrow, and therefore the impact clearly played a major role in extinctions
, but it probably wasn't just the impact," he added.
Probab y the result of an increase in the activity of undersea volcanism that deficiency led to mass extinctions
of life As scientists learn more about such events and the geological changes that led up to them, they see alarming Parallels with the warming world of today: history could be readying to repeat itself
But in order to be considered as proven and quantitatively explained, we need the kind of extensive, detailed work described by these teams to be conducted for all other extinctions
Summary: A projected spate of extinctions
of animals and plants this century may be less drastic than feared because the most widely used scientific method can exaggerate losses by more than 160 percent, a study said Wednesday.