3. Estimate the average time until extinction for a population of killer whales.
ID: 37593 • Letter: 3
Question
3. Estimate the average time until extinction for a population of killer whales. Assume that for the killer whale population the average growth rate (r) is zero. Based on the population size in 2001, what is your estimate for the average time to extinction?
4. How does T(N) change with the size of the initial population and with the variance in the rate of change in population size?
7. If this were always the case, why should we be worried about small populations? Under what conditions might you expect a population not to increase when reduced to low population size? This certainly has been the case for many endangered species that have gone extinct or now teeter on the edge. Do some populations simply not ?have what it takes? to maintain healthy levels?
3. Estimate the average time until extinction for a population of killer whales. Assume that for the killer whale population the average growth rate (r) is zero. Based on the population size in 2001, what is your estimate for the average time to extinction? 4. How does T(N) change with the size of the initial population and with the variance in the rate of change in population size? 5. fill in the expected times to extinction for the range of population sizes (N) and standard deviation of population growth rate (S) in table DA7-1: 6. What would be for the killer whale population at its largest and smallest sizes? If a population grows just by chance, does this mean that its prospects for long term survival improve? Assume that the sample standard deviation of r in the spreadsheet accurately estimates the underlying value of S. 7. If this were always the case, why should we be worried about small populations? Under what conditions might you expect a population not to increase when reduced to low population size? This certainly has been the case for many endangered species that have gone extinct or now teeter on the edge. Do some populations simply not ''have what it takes'' to maintain healthy levels?Explanation / Answer
The equation for time to extinction with r = 0, T(N) = (2/S2 ) × ln(1 + S2 N) +1. The observed value of S from the table above is 0.039 and N is 80 individuals. The expected time to extinction is about 152 years As N increases, T(N) also increases. As population size increases, the likelihood of extinction becomes smaller. As the variation in the population size increases, the time to extinction decreases. That is, increased variation makes extinction more likely. Several reasons attributed to this : 1) humans have altered the environment to reduce carrying capacity 2) there are Allee effects
Related Questions
drjack9650@gmail.com
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.