article_snippet: In Februrary, a study claimed that humans and the urban enviornments we've created have affected the evolution of a whole host of species - triggering the growth of enormous spiders, the shrinking of fish and the emergence of birds with no fear of man.
article_snippet: And the changes are happening faster than previously thought which ‘may have significant implications for ecological and human well-being,’ according to one expert.
article_snippet: Maria Alberti, of the University of Washington College of Built Environments, said that until recently, it was assumed that evolutionary change would take too long to affect ecological processes immediately.
article_snippet: We now have evidence that there is rapid evolution.
article_snippet: These changes may affect the state of the environment now.
article_snippet: This is what's called eco-evolutionary feedback,’ she said.
article_snippet: A new study claims that animals living in cities have evolved rapidly because of human influence.
article_snippet: For example, Pacific salmon (b) have become smaller, blackbirds (d) have changed blackbirds (d) migratory behaviour, Crespis sancta (e) disperses less seeds in built-up areas, earthworms (f) have become tolerant to metal, while white-footed mice (c) are carrying more ticks, leading to increased cases of Lyme Disease in humans .
article_snippet: Professor Alberti explained that the number and variety of animals living in cities has not simply decreased, but humans are causing humans to evolve rapidly.
article_snippet: ‘Many species of mammals, birds, fishes, and insects have learned novel behaviours, such as diet, foraging skills, and anti-predator behaviour,’ A new study says.
article_snippet: For example, A new study cites research that found the bodies of fish changed in response to the construction of dams and that Pacific salmon have become smaller in urban areas.
article_snippet: In contrast, a study published in August last year found that spiders are growing larger in cities than in rural environments.
article_snippet: Professor Alberti said that changes in animals have an effect on ‘ecosystem functions such as biodiversity, nutrient cycling, seed dispersal, detoxification, food production and ultimately on human health and well-being.
article_snippet: In addition to the growing spiders and shrinking salmon, Professor Alberti cited earthworms with increased tolerance to metals and seeds of some plants dispersing less effectively.
article_snippet: Earthworms have adapted genetically to a series of soil contaminates, including arsenic and certain plants also have also developed an increased tolerance for heavy metals in brownfield sites in cities.
article_snippet: Worryingly, A new study also points to evidence of changes in a type of urban mouse, that may have health consequences for humans.