First-Class Mail Letters 2014 Postage Rates 2013 Postage Rates Increase. First-Class Mail Letter (1 oz.) $0.49 $0.46 $0.03. NEW! First-Class Mail Letter (1 oz.) - Metered Mail/Stamps.com Rate* $0.48 N/A NEW! First-Class Mail Letter - each additional ounce $0.21 $0.20 $0.01.
A metapopulation is a group of populations that are separated by space but consist of the same species. These spatially separated populations interact as individual members move from one population to another.etapopulation Theory. Metapopulation theory states that a large population consisting of a single species is most stable over a large area when it is divided up into smaller subpopulations. These subpopulations take advantage of small, local environments, like your backyard or the park down the street.
Human overpopulation occurs if the number of people in a group exceeds the carrying capacity of the region occupied by that group.oncern about overpopulation is ancient. Tertullian was a resident of the city of Carthage in the second century CE, when the population of the world was about 190 million (only 3-4% of what it is today).