Final answer:
DNA methylation and histone modification are two examples of epigenetic phenomena observed in humans.
Step-by-step explanation:
Two examples of epigenetic phenomena observed in humans are DNA methylation and Histone modification.\
DNA methylation is the addition of methyl groups to the DNA, which can suppress transcription of genes. Histone modification involves the chemical modification of histone proteins, which can influence the accessibility of DNA for transcription.