A characteristic which helps an animal to live longer will generally tend to become more common in the population because as the animal produces more offspring those traits are passed down to them. Eventually it will be a common characteristic in the population.
Hope that helped :)
<u>Answer:</u> The tree was burned 16846.4 years ago to make the ancient charcoal
<u>Explanation:</u>
The equation used to calculate rate constant from given half life for first order kinetics:

where,
= half life of the reaction = 5715 years
Putting values in above equation, we get:

Rate law expression for first order kinetics is given by the equation:
![k=\frac{2.303}{t}\log\frac{[A_o]}{[A]}](https://tex.z-dn.net/?f=k%3D%5Cfrac%7B2.303%7D%7Bt%7D%5Clog%5Cfrac%7B%5BA_o%5D%7D%7B%5BA%5D%7D)
where,
k = rate constant = 
t = time taken for decay process = ? yr
= initial amount of the sample = 100 grams
[A] = amount left after decay process = 13 grams
Putting values in above equation, we get:

Hence, the tree was burned 16846.4 years ago to make the ancient charcoal
Crystallization above the ground and crystallization below the ground
This helps increase variation in the offspring.