genes related to brain development and function. Upper Paleolithic, or the Late Stone Age (50,000 to 12,000 years ago) Victorian naturalist Charles Darwin was the first to propose the out-of-Africa hypothesis for the peopling of the world, but the story of prehistoric human migration is now understood to be much more complex thanks to twenty-first-century advances in genomic sequencing. There were multiple waves of dispersal of anatomically modern humans out of Africa, with the most recent one dating back to 70,000 to 50,000 years ago. Earlier waves of human migrants might have gone extinct or decided to return to Africa. Moreover, a combination of gene flow from Eurasia back into Africa and higher rates of genetic drift among East Asians compared to Europeans led these human populations to diverge from one another at different times. Around 65,000 to 50,000 years ago, a variety of new technologies, such as projectile weapons, fish hooks, porcelain, and sewing needles, made their appearance. Bird-bone flutes were invented 30,000 to 35,000 years ago, indicating the arrival of music. Artistic creativity also flowered, as can be seen with Venus figurines and cave paintings. Cave paintings of not just actual animals but also imaginary creatures that could reliably be attributed to Homo sapiens have been found in different parts of the world. Radioactive dating suggests that the oldest of the ones that have been found, as of 2019, are 44,000 years old. For researchers, these artworks and inventions represent a milestone in the evolution of human intelligence, the roots of story-telling, paving the way for spirituality and religion. Experts believe this sudden "great leap forward"—as anthropologist Jared Diamond calls it—was due to climate change. Around 60,000 years ago, during the middle of an ice age, it was extremely cold in the far north, but ice sheets sucked up much of the moisture in Africa, making the continent even drier and droughts much more common. The result was a genetic bottleneck, pushing Homo sapiens to the brink of extinction, and a mass exodus from Africa. Nevertheless, it remains uncertain (as of 2003) whether or not this was due to some favorable genetic mutations, for example in the FOXP2 gene, linked to language and speech. A combination of archaeological and genetic evidence suggests that humans migrated along Southern Asia and down to Australia 50,000 years ago, to the Middle East and then to Europe 35,000 years ago, and finally