Our age has been called “post-evolutionary” because our bodies are increasingly changed by artificial adjustments rather than natural developments.
We now have organs replaced by manufactured parts and machines. Unlike the rest of the natural world, human bodies no longer change only through genetic adaptation and reproductive selection. Instead we are creating a new kind of human being by making artificial bones and organs. That is in addition to tinkering with genes, chemistry and environment.
Some worry about abuses and unforeseen problems in these medical advances, but they are no more failsafe than evolution itself. Natural selection experiences the extinction of whole species, so we can expect slips and failures as we change bodies robotically. Mistakes and accidents are a regular part of life, human and otherwise.
Like natural evolution, scientific adjustments can produce oddities and dysfunctional organs and species. Appendixes are leftover from previous stages of human development but they are relatively harmless. The same might not be said about spines which are still suffering from upright posture.
Artificial hearts under development now can be assumed to produce mixed results too. Some breast implants and cosmetic surgery have been reported to have failed at their modifications of bodies. Scientists and physicians experiment like nature itself with changes that lurch toward improvement. And in the complexity of human bodies they help and hinder at the same time.
In this new age things might not be so different.