Final answer:
Research supports the Out of Africa model, indicating that modern humans most likely descended from Africa, with genetic evidence showing a greater variation in Africa and genetic ties worldwide leading back to African origins.
Step-by-step explanation:
The statement that suggests variation is recent and that all populations should indicate an origin in Africa is supported by genetic findings. Research has shown that there is a wider genetic variation in the human population in Africa than in the rest of the world. This, along with the genetic ties of human genomes outside of Africa leading back to African genomes, supports the concept that modern humans most likely descended from Africa over 200,000 years ago. Research involving mtDNA has traced the matrilineal descent of early humans back to an African origin. Moreover, studies into the coevolution of humans and other organisms, such as lice, supplement our understanding of human history and evolution by filling in gaps left by the limited fossil record. This combined evidence upholds the Out of Africa model, which posits that modern humans originated from Africa and suggests the continent's human populations have the longest established genetic lineage.