Answer to Question 1
In the Tolai culture of the Melanesia islands, duk duk are male spirits, danced by maskers, who punish lawbreakers at the bidding of the community's leaders. Aztec masks were mosaics of turquoise, painstakingly applied in minute squares that followed every curve of the face. Pearl shells served for teeth and eyes. Such masks were worn in one of the numerous ceremonies of song and dance that were central to Aztec life. In the North American Lakota Indian culture, buffalo hides provided a surface on which Plains men recorded their exploits as warriors with painted images of battle scenes.
Answer to Question 2
Responses will vary depending the selection of works. Perhaps the greatest African art of spiritual agency is the masquerade, which doesn't contact spirit powers to effect change but brings the spirits into the community. Masks were employed in a performance aspect of the event and used to materialize spiritual beings. For the Tolai people of New Britain on the islands of Melanesia, masks and masquerades played important roles in their cultures. Their masks represented male and female spirits that are able to punish lawbreakers at the bidding of the community's leaders.
N95 respirator mask
How allopatric speciation works.
Example from Highland Papua New Guinea
Cara Grande feather mask, Tapirapé, Rio Tapirapé, Brazil.
The Works of Geoffrey Chaucer Newly Augmented, Kelmscott Press.
Young Guinea