Work breakdown structure is a structured approach for organizing all the project work and deliverables into logical groupings and subdividing them into more manageable components to help ensure all work and deliverables are complete until they are sub divided and can be assigned to a single person.
This is done so the work load can be converted into manageable sections which makes it easier to conduct logistical and managerial tasks. It also ensures the completions of task effectively and efficiently.
The bottleneck effect is the sharp in the population size due to the fact of the environmental changes such as the famines and the floods and the diseases and other events that lead to the variation in the gene pool s and thus a reduction of the species with a smaller remaining genetic diversity. The genetic drift causes the bottlenecks and this can create a random alternation of the alleles and leads to the loss of the species.