blue......................
So the dark butterfly camouflages better on the tree. Where as the white one can clearly be seen and identified. A predator will also easily spot it and kill it. The dark butterfly has evolved over time to the color that it is, to best help it survive. This is also shown in the tread on the graph.
Hope this helps!!
Because tropical levels used to be broken because temperatures hasn't varied in the years and history of global temperatures and history.
Answer:
![\mathbf{cummulative \ incidence = \dfrac{60}{1000}}](https://tex.z-dn.net/?f=%5Cmathbf%7Bcummulative%20%5C%20incidence%20%3D%20%5Cdfrac%7B60%7D%7B1000%7D%7D)
Explanation:
We recognize that total occurrence equals new cases of disease over time divided by the number of people at risk at the onset.
Mathematically:
![\mathbf{cummulative \ incidence = \dfrac{New \ cases \ of \ disease \ occurrence}{Number \ of \ population \ at \ risk \ at \ onset}}](https://tex.z-dn.net/?f=%5Cmathbf%7Bcummulative%20%5C%20incidence%20%3D%20%5Cdfrac%7BNew%20%5C%20cases%20%5C%20of%20%5C%20disease%20%5C%20occurrence%7D%7BNumber%20%20%5C%20of%20%5C%20population%20%5C%20at%20%5C%20risk%20%5C%20at%20%5C%20onset%7D%7D)
Given that:
Number of the population at risk = 1000 individuals
New cases during Jan 1 - Dec 31 = 60 because;
At 20 occurred on June 30 & 40 on Sept. 30) & no new cases were identified after that:
∴
![\mathbf{cummulative \ incidence = \dfrac{60}{1000}}](https://tex.z-dn.net/?f=%5Cmathbf%7Bcummulative%20%5C%20incidence%20%3D%20%5Cdfrac%7B60%7D%7B1000%7D%7D)