The Roman empire was physically united by good roads and bridges and secure sea lanes. It was mentally or spiritually united by the uniform code of laws, Roman citizenship in some cases, and the protection of the Roman military. Good communications due to the roads and courier system, gave the provincials a sense of belonging, instead of being treated like outsiders. The Romans also <span>established colonies of veterans or volunteers who were Roman citizens.</span>
Pathological aging is usually associated with older adults; it is a form of aging that is characterized by severe long term and short term memory loss. A feature of pathological aging is the increase in cerebrovascular and neurodegenerative disorders. Another feature of pathological aging is synaptic and neuronal loss. Individuals begin to forget things that they originally do not forget, like forgetting their driving routes.
Female bowerbirds prefer male bowerbirds that build large bowers. This is an example of intersexual selection. This term refers to when individuals of the same species compete with one another in order to win the chance to be able to mate with the opposite gender. In about all species this involves a male against male competition to win over the female.
In science the word "theory" basically means a model that has been confirmed countless times and never dis-confirmed (such as the theory of gravity). We call it a theory because it's something we had to discover and it was at first not certain.