9.
Name Stochastic factors (additional accidental)
that cause extinction.
Antwoord: 1 Environmental stochasticity: random unpredictable variation in, for example, rain fall and
food supply.
2 Demographic stochasticity: random variation in birth and death rates and sexratios due to
chance alone.
3 Catastrophes: extreme environmental events due to tornadoes, floods, harsh winters etc.
4 Genetic stochasticity: impacts of inbreeding, loss of genetic diversity and mutational
accumulation on species.
5 Inbreeding (inteelt): production of offspring from related parents. Inbreeding on average
reduces birth rates and increases death rates ( inbreeding depression).
6 Loss of genetic diversity: reduces the ability of populations to adapt to changing
environments via natural selection.