One in the major human activities leading for the irreversible biodiversity loss is the overexploitation of certain animals. This occurs when the human destruction or usage of a species outpaces that species' capability to reproduce. This often occurs when certain organisms are highly prized by humans, which could be the case with animals and plants whose parts are utilized as medicinal therapies in most societies. Sadly, three with the Earth's eight species of tiger happen to be extinct. What's worse? The five remaining species are gravely endangered, partly due on the interest in their bones, which are believed to treat arthritis, and erroneously believed to reverse male impotence. Exploitation also affects plants as well including popular wild-grown medicines ' including Echinacea, the normal cold remedy. However, the good thing is that its possible to raise your libido and testosterone naturally without even thinking of something as drastic as hormone replacement therapy. If you quit each time, at least you are doing something to avoid getting pregnant. But couples that rely only on sexual intercourse do tend to get pregnant.