After the European Rabbit Was Introduced into Australia in 1859

question 124

Essay

After the European rabbit was introduced into Australia in 1859, it quickly became a devastating invasive species, causing the extinction or decline of many native animals and plants, major damage to crops, and soil erosion. To control the exponential growth of the population (which had grown to an estimated 600 million individuals from an original 24), biologists infected rabbits with the myxoma virus in 1950. It is estimated that in the first years after introduction of the virus, as many as 99 percent of infected rabbits died. Over a period of years, however, biologists observed an increase both in the average life span of infected rabbits and in the percentage of rabbits surviving infection. How would you explain these changes?