Question

please i need your help a,b,c,d, e and F thank you

A. Please define the following terms x, 1x, 1x, and my from the life history table. (4 points) B. Please complete the remaining columns of this life table and show your work for the top most cell for the remaining columns to get full credit. (4 points) C. Calculate the net reproductive rate, generation time, and per capita rate of increase for this population and provide a biological explanation of what the net reproductive rate and generation time tells you about the population. (8 points) D. Which survivorship curve best describes this population and provide your reasoning for choosing this survivorship curve based on the data from the life history table? (3 points) E Is this population declining, stable, or increasing? For full credit, your answer must explain why you think that the population is either changing or not and what data from your calculations support your conclusion. (2 points) F. Which of the three life history strategies commonly employed by fish best fit the species described by this life table? For full credit, your answer must explain why you think that strategy is the best fit and what data from the table supports your conclusion. (4 points) mx lymx dy my l 1 Age (x) 0.00 1.00 2.00 3.00 0 1 0.4 0.2 0.1 3 5 3 4.00 nx 1000.00 400.00 200.00 100.00 60.00 50.00 35.00 20.00 15.00 10.00 0.00 2 1 5.00 6.00 7.00 0.06 0.05 0.035 0.02 0.015 0.01 0 0.5 0.3 0.2 8.00 9.00 10.00 0

Answer 1

A. The term 'x' is the life stage or age class; The term 'n_x' refers to the number of individuals at the beginning of the age interval x; The term 'l_x' is the proportion of original number of individuals surviving to the next stage or class, basically it means survivorship. The term 'm_x' refers to the fecundity rate, i.e average number of female offsprings produced per female in the population over a period of time.

B.

Age (x)	nx	lx	mx	lxmx	xlxmx
0.00	1000	1	0	$1\times 0=0$	= 0x0
1.00	400	0.4	1	0.4 x1= 0.4	0.4 x1= 0.4
2.00	200	0.2	3	0.2 x 3 = 0.6	$2\times 0.6=1.2$
3.00	100	0.1	5	$0.1\times 5=0.5$	$3\times 0.5=1.5$
4.00	60	0.06	3	$0.06\times 3=0.18$	$4\times 0.18=0.72$
5.00	50	0.05	2	$0.05\times 2=0.1$	$5\times 0.1=0.5$
6.00	35	0.035	1	$0.035\times 1=0.035$	$6\times 0.035=0.21$
7.00	20	0.02	0.5	$0.02\times 0.5=0.01$	$7\times 0.01=0.07$
8.00	15	0.015	0.3	$0.015\times 0.3=0.0045$	$8\times 0.0045=0.036$
9.00	10	0.01	0.2	$0.01\times 0.2=0.002$	$9\times 0.002=0.018$
10.00	0	0	0	= 0x0	$10\times 0=0$

C.The net reproductive rate is the mean number of female offsprings produced by a female during her lifetime. It is given by the relation, $R_{0}=\sum l_{x}m_{x}=0.4+0.6+0.5+0.18+0.1+0.035+0.01+0.0045+0.002=1.8215$

The mean generation time is given by the relation, $G=\frac{\sum xl_{x}m_{x}}{R_{0}}$ ; now, $\sum xl_{x}m_{x}=0.4+1.2+1.5+0.72+0.5+0.21+0.07+0.036+0.018=4.654$

$\therefore G=\frac{4.654}{1.8215}=2.555$

Per capita rate of increase is the change in population size per individual per unit time and is given by the relation, $r=\frac{\ln R_{0}}{G}=\frac{\ln 1.8215}{2.555}=0.234$

Now, as the net reproductive rate, R₀ > 1, so the population is increasing in size. The mean generation time, G is 2.555 years which means that the average age of females when they give birth to the offsprings is 2.555 years.

D. The survivorship curves is usually created by plotting l_x on the y-axis and age on the x-axis. The above population shows type III survivorship curve, as very few of the organism survive their younger years which is evident from the data in the column of l_x. The individuals those who have survived, live for long time. Species of this type of curve produce large number of offsprings at once.

E. The population is increasing, because, the net reproductive rate, R₀ >1 and per capita rate of increase, r > 0. So it can be said that the population is increasing.