idea

Natural selection^[1] is always happening one way or another, given that certain traits provide a better chance for reproduction.

Humans are still being selected, evolution favoring traits better adapted to modern life. Besides random biological adaptions such as intolerance to some proteins, or getting larger^[2], there can be two aspects to be considered: traits that kill, and traits that are adapted. Some external factors that might play a part in selecting tomorrow's human:

On average, people sleep less than recommended^[3]. Sleep deprivation, even mild, has consequences on health, and notably increases mortality, and induces reproductive issues^[4]. Some people have a genetic mutation (DEC2) that let them feel rested with less sleep then general human population^[5]. This should confer them achieve higher survival and reproduction rates.
Because being fat is associated with a large number of diseases such as diabetes, heart problems, circulatory problems, not being fat is an advantage. This confers higher chances of survival and reproduction to people that have higher metabolism, or lower attraction to sugary or fat food, or feel satiated more easily.
Depression -> people who feel happier naturally, or are ok with repetition

links

[1]: Natural Selection retains the fittest

references

[2]: Popular science / Yes, humans are still evolving. Here's how you can tell
[3]: Jeffrey Jones, Gallup News / In U.S., 40% Get Less Than Recommended Amount of Sleep
[4]: [Why we sleep] {todo: ref}
[5]: Ying He, Christopher R. Jones, Nobuhiro Fujiki, Ying Xu, Bin Guo, Jimmy L. Holder, Jr., Moritz J. Rossner, Seiji Nishino and Ying-Hui Fu / The Transcriptional Repressor DEC2 Regulates Sleep Length in Mammals

While performing candidate gene resequencing in DNAs from human families, segregating alleles for extremely early wake up times, we identified an hDEC2 point mutation in a small family with two affected individuals (Fig. 1A) (12). Subjects carrying this mutation had lifelong shorter daily sleep times than normal individuals (Table 1). The self-reported nonworkday habitual sleep-offset times of the mutation carriers were much earlier than those of the noncarriers (including noncarrier family members and general controls). However, these two individuals have sleep-onset times that are similar to that of conventional sleepers. The habitual self-reported total sleep time per 24-hour day was much shorter in mutation carriers (average 6.25 hours) compared with the noncarriers (average 8.06 hours) in this family