Question

what is the main cause of extinction on earth today

Answer 1

Habitat destruction, habitat fragmentation, the relocation of animals, and over hunting.

Answer 2

Hunting, not being bred well, and not a lot of food caused by us taking their environment.

Answer 3

Causes of extinction have prehistorically been dominated by natural earth processes such as geological transformation of the Earth's crust and major climatic oscillations, as well as species interactions; however, since the ascent of modern man during the Holocene, the causes of extinction have been dominated by the activities of humans. Rates of species extinction have increased rapidly since the early Holocene epoch, chiefly due to activities of humans; further acceleration of extinction rates began approximately 1600 AD, with the onset of accelerated human population growth and expanded scope of agriculture. Natural causes of extinction are regarded as being an irrelevantly small fraction of present extinction events, but are important to understand for historical and academic context. Darwin was the first to fully articulate the concepts of speciation and extinction as applied to natural succession, although he never used the terms evolution or extinction. (Darwin. 1859) The primary cause of human-induced extinction events is simply human overpopulation of planet Earth. The most important causal anthropogenic activities are habitat destruction, overexploitation, pollution and the introduction of alien species to an environment. Habitat destruction elements include agricultural land conversion, deforestation, overgrazing and urbanization; within these activities the process of habitat fragmentation is a sometimes hidden cause of major biodiversity loss. Overexploitation consists of intensive mineral and other geological resource extraction, overharvesting of wild flora and fauna (mainly for human food), hunting or fishing threatened fauna and killing of threatened fauna for herbal or cultural extracts. Pollution impacts include buildup of toxic atmospheric substances, discharge of water pollutants into natural water reserves, chemical contamination of soils and noise pollution. Introduction of alien species is usually an unintended activity where seeds, stowaway fauna aboard ships and other viably reproducing biota are transported by man to a new environment which has insufficient resident predators (or predators unfamiliar with, and therefore naive to the new prey) to control the invading taxon, or exotic predators inadvertently (or intentionally) introduced to a new region, where the native fauna are often unable to recognise the invading organism as a threat.