Question

In your own words, what is stochastic extinction? Why would stochastic extinction affect smaller populations more than larger populations?

Answer 1

SPECIES POPULATION ARE SUBJECTED TO DETERMINISTIC AND STOCHASTIC PROCESS BOTH OF WHICH CONTRIBUTE TO THE RISK OF EXTINCTION

DETERMINISTIC PROCESS DRIVE EXTINCTION WHEN GROWTH RATE IS LARGE.

STOCHASTIC PROCESS OFTEN DRIVE EXTINCTION RISK WHEN GROWTH RATE IS LOW

STOCHASTIC EXTINCTION AFFECT SMALLER POPULATION MORE THAN LARGER POPULATION BECAUSE:

POPULATION SIZE IS RELATED TO THE STRENGTH OF DRIFT AND THE LIKELIHOOD OF INBREEDING IN THE  POPULATION. SMALL POPULATION TEND TO LOOSE GENETIC DIVERSITY MORE QUICKLY THAN LARGE POPULATION . THIS IS BECAUSE SOME VERSIONS OF GENES CAN BE LOST DUE TO RANDOM CHANCE AND THIS IS MORE LIKELY TO OCCUR WHEN POPULATION SIZE IS SMALL. ADDITIONALLY SMALLER POPULATION MEANS INDIVIDUALS ARE MORE LIKELY TO BREED WITH CLOSE RELATIVES. BOTH INBREEDING AND DRIFT REDUCE GENETIC DIVERSITY WHICH HAS BEEN ASSOCIATED WITH INCREASED RISK OF POPULATION EXTINCTION, REDUCED POTENTIAL FOR RESPONSE TO ENVIRONMENTAL CHANGES AND DECREASED DISEASE RESISTANCE WHICH MAKES THE INDIVIDUALS OF THE POPULATION DIFFICULT TO SURVIVE AND REPRODUCE.