Iconicity, the direct resemblance between a linguistic sign and its meaning, is not a universal feature of language. While some languages may exhibit iconic elements, it is not a defining characteristic of all languages.

The duality of patterning principle states that language has two levels of structure: the level of sounds (phonology) and the level of meanings (semantics). This allows for the creation of an infinite number of meaningful utterances from a finite set of sounds.

The use of subject-verb-object word order is a linguistic universal, meaning that it is found in all languages. This word order is used to convey the relationship between the subject, verb, and object of a sentence.

Communicative competence refers to the ability to use language effectively in different social and cultural contexts. It includes knowledge of linguistic rules, as well as the ability to adapt one's communication style to different situations.

The use of hand gestures, facial expressions, and eye contact to communicate are all examples of communicative universals. These nonverbal behaviors are used in similar ways across cultures to convey messages and establish social connections.

The universality of language is supported by the fact that all cultures have a language, children from all cultures learn to speak, and language is necessary for human survival. Language allows us to communicate, share ideas, and cooperate with others.

The environmental adaptation hypothesis, which suggests that language evolved as a result of humans' need to adapt to their environment, is not a widely accepted explanation for the universality of language. The other three hypotheses are more commonly cited as potential explanations.

The innate language faculty hypothesis suggests that humans are born with a biological predisposition to learn language. This predisposition includes the ability to acquire the grammar and vocabulary of a language, as well as the ability to produce and understand speech.

The use of subject-verb-object word order is a language universal that supports the innate language faculty hypothesis. This word order is found in all languages, suggesting that it is a fundamental aspect of human language.

The cultural transmission hypothesis suggests that language is a learned behavior that is passed down from generation to generation through social interaction. This hypothesis emphasizes the role of culture and society in shaping language.

The fact that children learn to speak the language of their parents is evidence that supports the cultural transmission hypothesis. This suggests that language is a learned behavior that is passed down from generation to generation.

The social interaction hypothesis suggests that language is a product of social interaction. This hypothesis emphasizes the role of communication and interaction in the development and use of language.

The fact that language changes over time is evidence that supports the social interaction hypothesis. This suggests that language is a dynamic system that is shaped by the interactions between speakers.

The innate language faculty is not a proposed explanation for the diversity of languages around the world. The other three factors are commonly cited as potential explanations for linguistic diversity.

Geographical isolation can lead to the development of new languages because it prevents people from communicating with each other, allows them to develop their own unique culture, and creates a need for new words and expressions.