"what accounts for the similarities among all human beings everywhere in the world, such as the universal capacity for language or loyalty to a family or clan? "

The genetic dispositions which have developed during the evolution of humans.

Explanation:

The gene frequency of a population tend to change with time. Through changes in the genetic frequency, evolutionary changes in a species might occur.

However, there are some genes that will always be passed from the ancestors to the children. Each gene carries story of the human evolution. Though gene frequencies tend to change but there are certain characteristics or genetic dispositions which will always remain common among members of a species. The human genome is 99% similar to one another. Hence, this accounts for the similarities among human beings everywhere in the world.

question - in 1827, john walker, a druggist in a small english town, tipped a splint with sulphur, chlorate of potash, and sulphid of antimony, and rubbed it on sandpaper, and it burst into flame. the druggist had discovered the first friction-chemical match, the kind we use to-day. it is called friction-chemical because it is made by mixing certain chemicals together and rubbing them. although walker's match did not require the bottle of acid, nevertheless it was not a good one. it could be lighted only by hard rubbing, and it sputtered and threw fire in all directions. in a few years, however, phosphorus was substituted on the tip for antimony, and the change worked wonders. the match could now be lighted with very little rubbing, and it was no longer necessary to have sandpaper upon which to rub it. it would ignite when rubbed on any dry surface, and there was no longer any sputtering. this was the phosphorus match, the match with which we are so familiar. according the paragraph what was the benefit of the new phosphorus match? it burst into flame when rubbed on sandpaper. it was made by mixing chemicals. it could be ignited on any dry surface. it threw fire in all directions.

answer - matches required natural chemicals