In the past, Darwin thought that natural selection happened too slowly to be observed within a human lifetime. However, in the late 1900s, evolutionary biologists found significant changes occurring in a few species. Nowadays, scientists have discovered more instances of natural selection, indicating how quickly species can adapt to environmental changes. Interestingly, humans are unknowingly speeding up certain remarkable cases of evolution.
As greenhouse gases cause the average temperature of the planet to increase, certain species are adjusting to the changing climate. In California, biologist Arthur Weis from the University of Toronto and his team discovered that a seven-year drought had prompted the adaptation of field mustard plants. They announced in 2007 that these plants were genetically modified to bloom eight days earlier in the spring. http://www.pbs.org/wgbh/nova/evolution/ten-great-advances-evolution.html natural selection, evolution, mutation, variation, heritability, and fitness.
Field mustard, a scrawny annual plant with little yellow flowers, experienced a shorter growing season due to a severe drought in southern California between 2000 and 2004. During a drought, plants that flower earlier have a higher chance of leaving seeds compared to those that flower later. The latter are at risk of dying before completing their reproductive cycle. As the timing of flowering is largely influenced by genetics, a drought can lead to an evolutionary shift towards early flowering by favoring plants that bloom earlier.
Indeed, the beauty of plants lies in their ability to produce seeds, which are compact carriers of genetic material that can be conserved over time. Consequently, it is possible to directly compare the genes of plants from different eras. To demonstrate this, an experiment cultivated field mustard plants derived from seeds collected in both 1997 and 2004. The plants were raised under controlled circumstances and exhibited distinct variations in their flowering periods: notably, the plants from 2004 bloomed noticeably earlier.
During both years, seeds were collected from two different locations: one with sandy soil that had poor water retention and the other with soil that remained wet for long periods. The plants from the arid site exhibited a more significant change compared to those from the damp site. In just 7 years, natural selection led to an earlier flowering time in these plants (Source: http://opinionator.blogs.nytimes.com/2008/07/22/a-natural-selection/). This process is influenced by factors such as natural selection, evolution, mutation, variation, heritability, and fitness.
Shane Wright, an evolutionary biologist from the University of Auckland in New Zealand, states that species evolve more rapidly in tropical regions than in temperate areas. According to Wright, warmer temperatures accelerate bodily functions and reproductive rates in squid, leading to larger populations and greater genetic diversity. This increased genetic diversity increases the chances of future generations undergoing genetic mutations, which ultimately result in adaptations for specific water conditions and the emergence of new species.
In the past, it would take millions of years for an organism to undergo enough genetic changes to be considered a distinct species. The main way to determine if a species is new was its ability to reproduce with its parent species. However, recent discoveries show that plants and animals are evolving more quickly. An instance of this is seen in the weed field mustard in California, which now flowers earlier than usual after just seven generations. This could possibly be due to the droughts caused by global warming. Art Weis, a researcher at the University of California, Irvine, made this observation.
With the warming of the environment, some plants such as field mustard have the ability to flourish. This is because climate change can turn certain non-invasive exotic species into invasive ones. However, it is important to recognize that invasive plants and animals can inflict significant harm on an ecosystem. It should be acknowledged that undesirable neighbors include highly adaptable creatures like rats, cockroaches, jellyfish, and mosquitoes. In comparison, field mustard—a weedy plant—will outlive maple trees.
Due to early springs, Canadian squirrels are breeding earlier, giving them an advantage over New Hampshire loons who skipped winter migration this year due to abnormal lake freezing patterns. However, nature always finds a way to adapt and the increase in invasive species benefits certain animals. Approximately 50 million years ago, rising temperatures led to an increase in insects which was advantageous for bats, enabling them to thrive. Consequently, various bat species developed unique aviation and sonar abilities that enabled them to locate specific types of insects.
To learn more, you can visit http://www.smithsonianmag.com/science-nature/species.html#ixzz1dXsC8iZI.
