At this stage the population pyramid is broad at the base but since the mortality rate is high across all ages—and the risk of death is particularly high for children—the pyramid gets much narrower towards the top. • Stage 2: mortality falls but birth rates still high. In the second...
For example, whereas the basicranium develops early in life, with some components (e.g. the petrous pyramid of the temporal bone) almost fully formed in utero, other regions form later in life and are subject to epigenetic effects. Therefore, it was hypothesized that certain components of ...
At this stage the population pyramid is broad at the base but since the mortality rate is high across all ages—and the risk of death is particularly high for children—the pyramid gets much narrower towards the top. • Stage 2: mortality falls but birth rates still high. In the second...
The reasons for such slow growth are well known. In the absence of what is now considered basic knowledge of sanitation andhealth(the role of bacteria in disease, for example, was unknown until the 19th century), mortality rates were very high, especially for infants and children. Only...