The DNA repair ability of a cell is vital to the integrity of its genome and thus to the normal functionality of that organism. Many genes that were initially shown to influence life span have turned out to be involved in DNA damage repair and protection.
Examples for negative production externalities include: 1  Air pollution from burning fossil fuels. 2  This activity causes damages to crops, (historic) buildings and public health. 3  Anthropogenic climate change as a consequence of greenhouse gas emissions from burning oil, gas, and coal.
A positive externality (also called external benefit or external economy or beneficial externality) is the positive effect an activity imposes on an unrelated third party. Similar to a negative externality, it can arise either on the production side, or on the consumption side. Examples of positive production externalities include: 1  A beekeeper who keeps the bees for their honey. 2  A side effect or externality associated with such activity is the pollination of surrounding crops by the bees.