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The common blackbird (Turdus merula) may be the first example of actual speciation by urban evolution, due to the urban heat island and food abundance the urban blackbird has become non-migratory in urban areas. The birds also sing higher and at different times, and they breed earlier than their rural counterparts which leads to sexual ...
Urbanization over the past 500 years [13] A global map illustrating the first onset and spread of urban centres around the world, based on. [14]From the development of the earliest cities in Indus valley civilization, Mesopotamia and Egypt until the 18th century, an equilibrium existed between the vast majority of the population who were engaged in subsistence agriculture in a rural context ...
Humans are the driving force behind urban ecology and influence the environment in a variety of ways - urbanization being a key example. Urbanization is tied to social, economic and environmental processes. There are six core aspects: air pollution, ecosystems, land use, biogeochemical cycles, water pollution, solid waste management, and the ...
The United States Census Bureau changed its classification and definition of urban areas in 1950 and again in 1990, and caution is thus advised when comparing urban data from different time periods. [2] [3] Urbanization was fastest in the Northeastern United States, which acquired an urban majority by 1880. [2]
[27]: 2321 For example, the decline of sea ice in the Arctic has been accelerating during the early twenty‐first century, with a decline rate of 4.7% per decade (it has declined over 50% since the first satellite records). [28] [29] [30] One well known example of a species affected is the polar bear, whose habitat in the Arctic is threatened ...
The level of gene flow impacts its effects on local adaptation, high gene flow tends to reduce local adaptation whereas low gene flow can increase local adaptation. [17] High gene flow is when there is a lot of new genetic material entering the population often and low gene flow is when a population occasionally gets new genetic material.
Urban ecology is a relatively new field. Because of this, the research that has been done in this field has yet to become extensive. While there is still plenty of time for growth in the research of this field, there are some key issues and biases within the current research that still need to be addressed.
Examples include Johannesburg and Kimberley in South Africa, Ndola and Kitwe in Zambia and Lubumbashi in DR Congo. A strong centralised political system was also important in the development of early urban centres for example in the Ndebele Kingdom under Mzilikazi and later on Lobengula. Some cities were used and some were ignored.