How do organisms come to live on newly formed volcanic islands?

Through Primary succession

Explanation:

Succession is usually defined as the gradual and slow evolution of an organism over a specific period of time. It leads to the structural and morphological change of an organism. There are 2 types of succession, namely- Primary and Secondary succession.

Primary succession- In this type of succession, the initially occurring simple life forms, including both plants and animals first settles in a land area where there is no sign of life and is entirely an unproductive land. The newly formed volcanic islands are comprised of infertile soil particles and those species that first appear and settle here are termed as pioneer species. These organisms come to settle on a newly formed volcanic island through Primary succession.

this is math not biology xd