Hello. Your question is incomplete. However, I managed to find a question exactly like yours on the internet and managed to realize that you forgot to say that your question asks you to give an example of the statement presented above.
Answer:
A major disturbance from which the ecosystem was able to recover completely was the disease that almost wiped out all of Ireland's potato in 1840.
Explanation:
You may have heard of the Irish Potato Famine, which was a time when the Irish population lived very difficult days, after an illness that almost decimated the country's potato plantations.
The potato was the main source of food for the Irish, but in 1840, a fungus called Phytophthora infestans, managed to infect almost all potato plantations in the country, preventing the potato from being harvested and could be consumed. This created major economic and social problems in Ireland, as people suffered from hunger, poverty and the diseases that arose, which caused many Irish people to immigrate to other countries, or to die.
The fungus plagued the ecosystem for years and only started to decrease in intensity in 1850, once the ecosystem started to recover. Currently, although the pest still exists, the Irish ecosystem is completely recovered and the pest is controlled and is unable to make such an impact.
 
        
             
        
        
        
A) A textbook definition would be that genetic drift is: a random change in allele frequency caused by a series of chance occurences that cause an allele to become more or less common in a population. In layman's terms, this means that genetic drift happens when luck makes the genetic pool of the population to deviate from what is expected.
B) The cause for this genetic drift is the aformentioned couple. Because amish communities are small and they select partners from their community, having even a couple of carriers of alleles in a community can make the allele freuency much larger than expected; for example, if the community was 100 persons, the percentage would be in the order of 1%, still much larger than the general population. Thus, the cause here is that a small population had a couple of carriers.
C) Sexual reproduction leads to a mixing of alleles from both mother and father and helps diversity. When a population is isolated, the gene pool is fixed and no new genes can come in, reducing diversity. Also some people that have an allele might die, hitting diversity even more. Finally, having a small population creates a strong pressure in some circumstances that leads to elimination of some traits and diversity.
        
             
        
        
        
Answer:
<u><em>The correct option is C) genetic variation</em></u>
Explanation:
Genetic variation can be described as the differences present in the genetic material i.e DNA of organisms present in a population. Genetic diversity allows organisms of a species to better adapt to an environment. A population in which the genetic variability is scarce might become wiped out by a disease or an invading predator.
As the birds show different variations hence the term that best described them is genetic variation. 
 
        
                    
             
        
        
        
Answer:
You will measure the rate of your pules and how fast its going. 
You need to keep the thing you are doing for example( if your running you have to make the people run the same length as every one else.  
I hope this helps :)
Explanation:
 
        
                    
             
        
        
        
Hi!  I can help you out.
RNA polymerase binds to regions of DNA called promoters, which are "start" signals for transcription