Acquired characteristic

An acquired characteristic is a non-heritable change in a function or structure of a living biotic material caused after birth by disease, injury, accident, deliberate modification, variation, repeated use, disuse, or misuse, or other environmental influences. Acquired traits, which is synonymous with acquired characteristics, are not passed on to offspring through reproduction alone.

The changes that constitute acquired characteristics can have many manifestations and degrees of visibility but they all have one thing in common: they change a facet of a living organisms' function or structure after the organism has left the womb.

Acquired characteristics can be minor and temporary like bruises, blisters, shaving body hair, and body building. Permanent but inconspicuous or invisible ones are corrective eye surgery and organ transplant or removal. Semi-permanent but inconspicuous or invisible traits are vaccinations and laser hair removal. Perms, tattoos, scars, and amputations are semi-permanent and highly visible.

Applying makeup and nailpolish, dying one's hair or applying henna to the skin, and tooth whitening are not examples of acquired traits. They change the appearance of a facet of an organism, but do not change the structure or functionality.

Inheritance of acquired characters was historically proposed by renowned theorists such as Hippocrates, Aristotle, and French naturalist Jean-Baptiste Lamarck. Conversely, this hypothesis was denounced by other renowned theorists such as Charles Darwin. Today, although Lamarckism is generally discredited, there is still debate on whether some acquired characteristics in organisms are actually inheritable.

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