The individual genotypes in a breeding population, taken as a whole, are the gene pool.
A gene pool can be described as a collection of different genes(includes both genes expressed, and not expressed) within an interbreeding population. Definition of the gene pool can also be: the sum of all the alleles at all of the loci within the genes of a population of a single species.
The answer to your question is Burning of Fossil Fuels
<u>Answer</u>: (1 is the oldest event)
1. Europe sent explorer and merchants along the Silk Road and across the Indian Ocean
2. European nations colonized countries in Southeast Asia
3. World War II broke out in Europe as well as in East Asia and Southeast Asia
4. Nations in Southeast Asia demanded and won independence
Multiple nations in Southeast Asia obtained their independence after World War II some as late as 1975 (Portuguese Timor - now East Timor).