- Comments were made by Professor Menno Schilthuizen at Leiden University
- ‘I think Darwin underestimated the speed [that evolution] can happen,’ he said
- Cities have forced great tits learn to learn to open caps off milk bottles and lizards have developed stickier feet to climb up buildings
Our cities are ‘powerhouses of evolution’ where animals are adapting to their environment at ‘unprecedented speeds’.
That’s according to evolutionary biologist Menno Schilthuizen who claims that, far from being desolate wastelands, cities are helping create new species.
Professor Schilthuizen, who is author of ‘Darwin Comes to Town’, claims humans are helping speed up this process, with some surprising results.
Our cities are ‘powerhouses of evolution’ where animals are adapting to their environment at ‘unprecedented speeds’. For instance, bobcats in Hollywood have evolved to be genetically different from those living north of the 101 freeway
In an in-depth interview with National Geographic’s Simon Worrall, Processor Schilthuizen explains how cities are creating a new breed of ‘London Underground Mosquito’.
Despite its name, the London Underground Mosquito can be found all over the world living in underground environments such as basements and subway systems.
The London Underground mosquito can no longer interbreed with its above ground counterpart and is effectively thought to be a new species.
‘I think Darwin underestimated the speed [that evolution] can happen, particularly with species that have numerous generations in a short space of time,’ Professor Schilthuizen, who is also a professor in biodiversity at Leiden University in The Netherlands, told National Geographic.
‘Generation time is the evolutionary clock speed, so if you have multiple generations per year you can accumulate evolutionary changes much more quickly than humans can, for example, which have one generation every 20 years.’
In another example, Professor Schilthuizen highlights the fact that bobcats in Hollywood are now different from those living north of the 101 freeway.
‘Fragmentation in cities is a common theme. In urban ecology humans create all kinds of barriers, like roads and highways,’ said Professor Schilthuizen.
The London Underground mosquito can no longer interbreed with its above ground counterpart and is effectively thought to be a new species
‘North of Los Angeles, the bobcat population is divided by two very large highways, which bisect the area where they live.
‘These barriers cause something similar to what happens to mosquitoes in the London subway lines, whereby evolution is restricted to the areas cut off from other populations.’
Recent research has found that mammals living in areas with high human activity move up to three times less far than animals in areas isolated from people.
This pattern persists globally, from African forest elephants to foxes and red deer in Britain, affecting mammal species both big and small.
Human-caused changes to the environment could affect animals in a number of important ways.
If food is more abundant because of nearby humans, either because they feed the animals or leave scraps in bins, mammals may not have to travel as far.
Restricted movement could also result from habitat fragmentation as humans build settlements, fences and roads that cut off animals from certain areas.
Blocking animal migration allows for the easy spread of deadly diseases and makes it harder for species to mate and find food and shelter.
In his book, Professor Schilthuizen also describes how Hawksbeard plants in small parks create heavier seeds than those in open fields, so they’re more likely to land in soil.
Urban evolution has also meant that great tits learn to open caps off milk bottles, and lizards develop stickier feet to cling to buildings.
Professor Schilthuizen’s book follows a recent study by Goethe University in Frankfurt, Germany, that found animals worldwide are giving up their ‘wild ways’ and sticking closer to home as a result of human activity.
Urban evolution has also meant that great tits learn to open caps off milk bottles, and lizards develop stickier feet to cling to buildings
Experts tracked the effect of human activity via a measure of human activity known as the Human Footprint Index (pictured). The HFI measures how much our species has impacted an area using factors such as population density and the presence of roads and night-time lights
The study found mammals living in areas with high human activity move up to three times less far than animals in areas isolated from people.
This pattern persists globally, from African forest elephants to foxes and red deer in Britain, affecting species both big and small.
Experts say that human settlements, roads and fences break up their natural habitat and block the natural migration of mammals, allowing for the easy spread of deadly diseases.
This habitat ‘fragmentation’ also hinders animals’ ability to mate and find shelter and food.
Reduced mammal movement also has an affect on the environment as many plants rely on mammals to disperse their seeds.
‘The importance of the geographical movement of animals in the wild has long been documented,’ said study coauthor Dr Adam Kane, from the University College Cork, Ireland.
‘It is necessary for the animals to find food, water, mates and new habitats to live in.’
Researchers found that, on average, mammals living in human-modified habitats move two to three times less far than their counterparts in human-free areas. The researchers tracked the movement of lions in Tsavo, Kenya (pictured) as part of their stud