Because of the general similarities in life surroundings and modes of thinking, the English language and the Chinese language have many coincidences on meanings and forms in using negation.
The differences between the groups and the similarities within each group made it seem certain to most biologists that the tree of life had only two stems.
If identical twins are more similar to each other with respect to an ailment than fraternal twins are, then vulnerability to the disease must be rooted at least in part in heredity.