Most extinctions can be prevented by implementing conservation strategies such as legal remedies, preserving natural plant and wildlife habitats and using synthetic medicines not derived from plant and animal products. Preventing extinction requires an understanding of its root causes, which include natural events and human activity. Although extinctions from natural causes cannot be prevented, human behavior may be modified to give flora and fauna worldwide a greater chance of survival.
In the broadest sense, extinction may be caused by two activities: natural earth processes and human activities. In prehistoric times, generally before the Holocene era, extinction was caused primarily by changes to the earth’s surface, including volcanic eruptions, glacial melt and drying out or filling in of lakes, oceans and other bodies of water. Fluctuations in the climate, including extended periods of global warming and cooling, also factored into species survival. As in modern times, events such as earthquakes, floods, droughts and fires played roles in species survival. Interaction between different species and evolutions within certain populations also influenced their rates of long-term survival. These natural factors contributed to the extinction of some prehistoric flora and fauna species, but their rate of extinction accelerated dramatically during the Holocene era as human populations grew worldwide. Since that time, humans have been the primary contributors to global species declines and extinctions.
Although natural events play a role in extinction, their contributions to population decline are minimal in comparison with man-made factors. Biologists attribute four main factors to human-caused extinctions: habitat loss and destruction, overexploitation of natural resources, air and water pollution and introduction of non-native and alien species. Habitat destruction, in the broadest sense, is attributed to the conversion of land for agricultural use, deforestation, overgrazing and urban growth and development. These activities may cause habitat fragmentation, which is a growing problem in densely populated areas and contributes to widespread loss of biodiversity. Overexploitation occurs from many sources, including mining, excavating and extraction of geological resources, such as minerals and gems. In many areas of the world, humans harvest excessive numbers of flora and fauna for food and economic purposes, such as creating clothes and bedding and making medicines. In addition to overharvesting, the growth of human urban centers increases air and water pollution. These pollutants include harmful airborne particles, chemicals that leach into water supplies and microorganisms that find their way into soils and disrupt their natural abilities to carry out vital life functions. Lastly, the introduction of nonnative species changes the way entire ecosystems function; when exotic predators are introduced into new areas, native species do not recognize them as threats and are consequently killed off.
Some extinctions are inevitable; the earth’s surface always changes, and natural events such as floods, droughts, fires and famines will always occur even in the absence of the human population. But many factors that contribute to extinction are caused by human behavior and activity, which can be modified. This is where long-term conservation strategies play important roles in ensuring the longevity of flora and fauna. These strategies include legal remedies, such as enactment of laws listing species as threatened or endangered and imposing penalties on excessive harvesting and capturing and trade of dwindling species; the exploration of novel medicines and antidotes derived from synthetics rather than plants and animals; education and setting aside critical habitat areas to preserve the original habitats of native species.