Evolution can be define as the change that occur in a particular species over a time. Such changes are because of natural selection of favorable traits responsible for the survival of the organisms under unfavorable conditions.
a. Increasing phenotypic complexity over time: Some of the phenotypic traits make the organism suitable for survival of the species. These traits are transferred to the members of the next generation. This process leads to the development of new species.
b. A change occurring in individuals as a result of selection: The evolution is a change that occur after the process of natural selection as the organism adapts according to the traits they exhibit.
c. Descent with change: The ancestors are the organisms which undergoes changes such changes are transferred to the new generation that is descents.
The bluish color of veins is only an optical illusion. Blue light does not penetrate as far into tissue as red light. If the blood vessel is sufficiently deep, your eyes see more blue than red reflected light due to the blood's partial absorption of red wavelengths.
the hormone erythroprotein increases the production of red blood cells when oxygen levels are low best supports teh statement taht hormones are involved in the regulation of homesstasis.