Interbreeding between archaic and modern humans been shown that Neanderthal ancestry has been selected against in conserved biological pathways, such as RNA processing. Consistent with the hypothesis that purifying selection has reduced Neanderthal contribution in present-day modern human genomes, Upper Paleolithic Eurasian modern humans (such as the Tianyuan modern human) carry more Neanderthal DNA (about 4–5%) than present-day Eurasians modern humans (about 1–2%). Genes affecting keratin were found to have been introgressed from Neanderthals into modern humans (shown in East Asians and Europeans), suggesting that these genes gave a morphological adaptation in skin and hair to modern humans to cope with non-African environments. This is likewise
What to the Slave Is the Fourth of July? under the sea, as well as on the earth. In the United States, the speech is widely taught in history and English classes in high school and college. American studies professor Andrew S. Bibby argues that because many of the editions produced for educational use are abridged, they often misrepresent Douglass's original through omission or editorial focus. The speech has been notably performed or read by important figures, including the following actors: What to the Slave Is the Fourth of July? "What to the Slave Is the Fourth of July?" is the title now given to a speech by Frederick