Give arguments proving that all modern humanity belongs to the same species.

A species is a group of individuals that have the same external and internal structure, life processes; freely interbreed with each other and give fertile offspring. Representatives of the same species have a similar chemical composition and the same set of chromosomes.
Modern humanity is representatives of the species – Homo sapiens:
– the chromosome set of all people – 46 chromosomes;
– interracial blood transfusions and organ transplants are possible;
– full-fledged children are born in interracial marriages.