It is called speciation.
when members of two separated groups of a population can no longer interbreed, the two groups are members of different what
A population that becomes divided (isolated) by a physical barrier, allowing each of the separated groups an independent evolutionary path.
A newly formed canyon, mountain range, or lake can seperate individuals.
isolation due to population groups reproducing at different times.
Population isolation of some sort.
Cells can be separated into prokaryotic and eukaryotic cells.
stratificatin
Speciation :D
first scientists grouped organisms into groups . Each group was called phylum. Then they separated each phylum into smaller and smaller groups called class
the mountains
In stratified sampling, the population to be sampled is divided into groups (strata), and then a simple random sample from each strata is selected. For example, a state could be separated into counties, a school could be separated into grades. These would be the 'strata'.
Commas are used to separate large numbers into groups of three digits. Each group is called a period.