Eye - Evolution. 1  Photoreception is phylogenetically very old, with various theories of phylogenesis. [26] 2  Eyes in various animals show adaptation to their requirements. 3  The very earliest eyes, called eyespots, were simple patches of photoreceptor protein in unicellular animals.
Synthetic fibers or fibres are the result of extensive research by scientists to improve on naturally occurring animal and plant fibers. In general, synthetic fibers are created by extruding fiber forming materials through spinnerets into air and water, forming a thread.Before synthetic fibers were developed, artificially manufactured fibers were made from polymers obtained from petro chemicals. These fibers are called synthetic or artificial fibers.oseph Swan invented the first synthetic fiber in the early 1880s. His fiber was drawn from a cellulose liquid, formed by chemically modifying the fiber contained in tree bark.
There are two polyolefin polymers used to make synthetic fibres, polypropylene and polyethylene, with polypropylene being by far the most important.roperties and End-Uses. Both polyolefin fibres have a density less than 1.0 and therefore, at a given decitex, are thicker than other man-made fibres and give more cover. They do not absorb moisture, which is an advantage in many end-uses, but without modification, they cannot be dyed.