This adjective is meaning of social development pdf much more often by those on the political left than by those on the political right. For these reasons, those seeking to avoid association with the left-right political debates often seek to label their work with phrases that do not include the word “social”. The modern concept of socialism evolved in response to the development of industrial capitalism.
The “social” in modern “socialism” came to refer to the specific perspective and understanding socialists had of the development of material, economic forces and determinants of human behavior in society. This page was last edited on 20 December 2017, at 13:01. Most species live in the sea, some in rivers. Dolphins are able to make very tight turns while swimming at high speeds. Some species are well adapted for diving to great depths.
Although cetaceans are widespread, most species prefer the colder waters of the Northern and Southern Hemispheres. This has drastically affected their anatomy to be able to do so. Calves are typically born in the fall and winter months, and females bear almost all the responsibility for raising them. Cetaceans have been depicted in various cultures worldwide.
Most mysticetes prefer the food-rich colder waters of the Northern and Southern Hemispheres, migrating to the Equator to give birth. During this process, they are capable of fasting for several months, relying on their fat reserves. Their hearing is so well-adapted for both air and water that some blind specimens can survive. Some species, such as sperm whales, are well adapted for diving to great depths. Cetacean bodies are generally similar to that of fish, which can be attributed to their lifestyle and the habitat conditions. They have a streamlined shape, and their forelimbs are flippers. Both the flipper and the fin are for stabilization and steering in the water.
The male genitals and mammary glands of females are sunken into the body. Males in these species developed external features absent in females that are advantageous in combat or display. The fluke is set horizontally on the body, unlike fish, which have vertical tails. The nostrils are located on top of the head above the eyes so that the rest of the body can remain submerged while surfacing for air. The back of the skull is significantly shortened and deformed. By shifting the nostrils to the top of the head, the nasal passages extend perpendicularly through the skull.
The braincase is concentrated through the nasal passage to the front and is correspondingly higher, with individual cranial bones that overlap. Even the long tusk of the narwhal is a vice-formed tooth. In many toothed whales, the depression in their skull is due to the formation of a large melon and multiple, asymmetric air bags. Other cetaceans have fused neck vertebrae and are unable to turn their head at all. In humans, these cells are thought to be involved in social conduct, emotions, judgment and theory of mind. Since most of the brain is used for maintaining bodily functions, greater ratios of brain to body mass may increase the amount of brain mass available for cognitive tasks.
In some whales, however, it is less than half that of humans: 0. Blue Whale skeleton outside the Long Marine Laboratory of the University of California, Santa Cruz. Skeleton of a blue whale standing outside the Long Marine Laboratory of the University of California, Santa Cruz. Upper jaw of a sperm whale that has been weathered and yellowed.