Does Urbanization Trigger Plant Evolution? | CHIBADAI NEXT
Creeping woodsorrell (green-leaved form),
Oxalis corniculata.
Common in rural areas
Oxalis corniculata.
Common in rural areas
The traditional response by creationists to these examples is to try to get away with a different definition of biological evolution to include changes that biologists don't claim ever happen, such as an entirely new taxon arising in a single event, or one taxon changing into another, unrelated taxon. It matters not one iota to a creationists that they may have been corrected on this point numerous times, it's almost impossible to shift them away from their protective shell of pretending science makes claims science never makes and the definition of biological evolution is something so absurd that no sane person could accept it.
First, a short conversation with ChatGPT3.5 on the definition of biological evolution and why creationists need to misrepresent the science:
What is the scientific definition of biological evolution? Biological evolution, in scientific terms, is the process by which populations of living organisms change over time. It is a fundamental concept in the field of biology and is the mechanism responsible for the diversity of life on Earth. The key components of the scientific definition of biological evolution include:Back now to the case in hand - the observed difference in the distribution of the two leaf-colour forms of a common weed plant, the creeping woodsorrel, which I think is a rather attractive little plant, especially the red-leaved form when growing in gravel, as it does in my front garden.The theory of evolution, first proposed by Charles Darwin and Alfred Russel Wallace in the 19th century, is supported by extensive scientific evidence from various fields, including paleontology, genetics, comparative anatomy, and molecular biology. It is a foundational concept in biology and has greatly contributed to our understanding of the natural world and the history of life on Earth.
- Descent with Modification: Evolution involves the passing of genetic information from one generation to the next with modifications or changes. This descent with modification is what leads to the diversity of species and the development of new traits over time.
- Change in Allele Frequencies: Evolution is driven by changes in the frequency of alleles (different forms of genes) within a population. These changes can occur through various mechanisms such as natural selection, genetic drift, mutation, and gene flow.
- Natural Selection: One of the most important mechanisms of evolution is natural selection. This process favors individuals with traits that enhance their survival and reproduction in a given environment. Over time, these advantageous traits become more common in a population.
- Speciation: Evolution can lead to the formation of new species. This occurs when populations of a species become so different from each other that they can no longer interbreed and produce viable offspring.
- Gradualism and Punctuated Equilibrium: Evolution can occur gradually over long periods of time or in relatively rapid bursts of change. The two major theories to explain the pace of evolution are gradualism, where changes happen slowly and steadily, and punctuated equilibrium, where there are periods of relative stability followed by rapid change.
- Common Ancestry: All living organisms share a common ancestry. This means that all life on Earth, from bacteria to humans, can be traced back to a single common ancestor through the process of evolution.
Would you say then that 2. in your response is a succinct definition of biological evolution?
Yes, you could consider point 2, "Change in Allele Frequencies," to be a succinct definition of one of the fundamental aspects of biological evolution. It highlights the core concept that evolution involves changes in the frequencies of alleles (different versions of genes) within a population over time. These changes in allele frequencies can result from mechanisms such as natural selection, genetic drift, mutation, and gene flow. While it captures a key element of evolution, it's important to recognize that evolution is a complex and multifaceted process with various contributing factors and mechanisms, as described in the broader definition.
Why do creationists define biological evolution as a new taxon arising in a single event, or one species turning into another, unrelated species in a single event?
Creationists, who often hold religious beliefs that conflict with the mainstream scientific understanding of evolution, may define biological evolution in the way you described for a few reasons:
Simplification and Misrepresentation: By characterizing evolution as a new taxon or one species turning into another in a single event, creationists might be simplifying the concept to make it easier to criticize or reject. This simplified representation can be a mischaracterization of the nuanced and gradual processes of evolution that scientists have uncovered.
Theological and Worldview Conflicts: Many creationists hold religious beliefs that include specific interpretations of the origins of life and the diversity of species. These beliefs often center around a divine creator and the idea that species were created separately and do not share a common ancestry. Defining evolution as a sudden and unrelated transformation aligns with their religious or worldview positions, allowing them to reject evolutionary theory without reconciling it with their beliefs.
Straw Man Argument: By presenting a simplified and often incorrect definition of evolution, creationists can set up a "straw man" argument. This involves attacking a distorted version of evolutionary theory that is easier to criticize, rather than engaging with the actual scientific evidence and theory of evolution. This can be a rhetorical strategy to undermine the credibility of mainstream science.
It's important to note that the scientific understanding of biological evolution, as described by the theory of evolution, is based on extensive empirical evidence and is widely accepted within the scientific community. It does not involve sudden or unrelated transformations of species, but rather gradual changes in allele frequencies over long periods of time, leading to the diversity of life we observe today. Creationist perspectives on this topic often stem from religious or ideological beliefs and are not based on scientific principles or evidence.
Is there a name for this psychological process of misrepresentation and mischaracterisation to sustain a counter-factual belief?
The psychological process of misrepresentation and mischaracterization to sustain a counter-factual belief can be understood through various cognitive and psychological phenomena. Some terms and concepts related to this process include:These psychological processes can contribute to the misrepresentation and mischaracterization of information to sustain counter-factual beliefs. They highlight the complex interplay between cognition, emotion, and belief systems, and they can make it challenging to engage in productive discussions or change deeply held beliefs, even in the face of compelling evidence.
- Confirmation Bias: This is a cognitive bias that leads individuals to seek out, interpret, and remember information in a way that confirms their preexisting beliefs. People may downplay or ignore information that contradicts their beliefs while amplifying information that supports them.
- Cognitive Dissonance: When individuals hold conflicting beliefs or attitudes, they may experience cognitive dissonance, a psychological discomfort. To reduce this discomfort, they may engage in processes like rationalization or reinterpretation of evidence to maintain consistency with their existing beliefs.
- Motivated Reasoning: This is the tendency to evaluate and interpret information in a way that is consistent with one's preexisting beliefs, desires, or goals. People may unconsciously or consciously "motivate" their reasoning to align with their desired outcomes.
- Backfire Effect: In some cases, presenting evidence that contradicts a person's beliefs can actually strengthen those beliefs rather than change them. This is known as the backfire effect, and it can lead individuals to double down on their existing beliefs in the face of conflicting evidence.
- Illusory Truth Effect: Repeated exposure to false or misleading information can make it seem more credible and true to individuals. Over time, they may come to accept such information as fact, even when it is not supported by evidence.
- Selective Perception: People tend to pay attention to and remember information that supports their beliefs while disregarding or forgetting information that contradicts them. This selective perception can reinforce existing beliefs.
- Belief Perseverance: This is the tendency for people to hold onto their beliefs even when presented with evidence that disconfirms those beliefs. It can be difficult for individuals to change their views, especially if the beliefs are deeply ingrained.
This is the subject of an open access paper in Science Advances by a team led by Associate Professor Yuya Fukano of Chiba University, Chiba, Japan, including colleagues from Tokyo University, Tokyo Metropolitan University and Kazusa DNA Research Institute, Chiba, Japan.
The research is explained in a Chiba University press release:
Researchers from Japan uncover how urbanization impacts plant evolution and stress adaptation in the creeping woodsorrel plant.
Urban environments have become hotspots for understanding how rapid evolution occurs in response to extreme environmental changes. These habitats exert selective pressures on resident organisms that impact their evolutionary trajectories. Recently, researchers from Japan investigated how the creeping woodsorrel plant might adapt in response to elevated temperatures that result from urbanization. Understanding these effects can help predict evolutionary traits to manage plant evolution in the face of shifting climatic conditions.Urbanization and human activities have transformed a significant proportion of the land on Earth, resulting in the formation of urban environments. These urban environments are man-made habitats that often impose several selective pressures on their inhabitants. A key characteristic of such environments is the presence of impermeable, heat-retaining surfaces created using brick, stone, asphalt, and concrete. Notably, these surfaces form urban heat islands, i.e., regions with elevated surface temperatures. An unexpected result of heat stress is the impact on the behavior, physiology, and evolutionary trajectories of resident organisms. Although several studies have investigated the role of urban heat stress on evolution in animals, its effects on plant evolution remain largely unexplored.Role of heat stress on leaf color evolution in Oxalis corniculata 
A recent study examined the role of heat stress over the growth and survival of green and red Oxalis corniculata variants in controlled and uncontrolled cultivation setups. This figure depicts a comparison of various parameters between green- and red-leaved variants of O. corniculata under different cultivation conditions.Yuya Fukano, Chiba University (CC BY 4.0)
To address this gap, a team of researchers led by Associate Professor Yuya Fukano from the Graduate School of Horticulture, Chiba University, Japan, investigated how urban heat islands affect the leaf colors of Oxalis corniculata, also known as the creeping woodsorrel. This plant exhibits diverse leaf colors ranging from green to red and is found in both urban and non-urban spaces across the world. Research suggests that these color variations serve as an evolutionary adaptation to protect the plant from environmental stress. Moreover, red pigments (anthocyanins) in the leaves are thought to mitigate heat and light-induced damage by intercepting light and forming antioxidants.
To investigate this evolutionary theory, Dr. Yuya Fukano and his team, comprising Dr. Wataru Yamori from the University of Tokyo, Dr. Yuuya Tachiki from Tokyo Metropolitan University, and Dr. Kenta Shirasawa from the Kazusa DNA Research Institute, conducted field observations of the leaf color distribution in the creeping woodsorrel, across urban and non-urban regions at the local, landscape, and the global scales. Their study findings were published in Science Advances on October 20, 2023.
We noticed that the red-leaved variants of the creeping woodsorrel commonly grew near impervious surfaces in urban areas but rarely grew in farmlands or green spaces in and around the city.
Dr. Yuya Fukano, lead author
Associate Professor
Graduate School of Horticulture
Chiba University, Chiba, Japan.
The team identified a pattern where green-leaved variants of the creeping woodsorrel dominated green spaces while their red-leaf counterparts dominated the urban sites of Tokyo at both the local and landscape levels. Upon further examination of an online database, the team discovered that these geographical findings were consistent across the globe, thereby confirming a link between urbanization and leaf color variations in the creeping woodsorrel.
This motivated the team to quantify the adaptive benefits of these leaf color variations by examining their influence over biomass growth and photosynthetic ability under heat stress and non-heat stress conditions across controlled and uncontrolled cultivation experiments.
Through these experiments, the team found that the red-leaf variants exhibited superior growth rates and higher photosynthetic efficiency under high temperatures, whereas green-leaf variants thrived in lower temperatures. As a result, red-leaf variants tend to thrive in urban areas with low plant density due to high stress tolerance. The opposite is true for their green-leaf counterparts, which display higher growth competitiveness in lush green areas. “Although these findings will not change much in the immediate future, this study showcases one of the most popular examples of ongoing evolution that can be observed in urban areas,” remarks Dr. Fukano.
The team also conducted genome-wide genetic analyses, which indicated that the red-leaf variant of O. corniculata may have evolved multiple times from the ancestral green-leaf plant.
These adaptations to high-temperature stress likely extend beyond leaf color, thereby warranting further research into various plant traits for a comprehensive understanding of plant adaptation to urban heat islands.Urban heat islands are precursors to global warming. Understanding the rapid adaptive evolution of urban organisms to high temperatures will provide valuable insights on ecosystem dynamics and sustainable crop production.
Dr. Yuya Fukano
AbstractTo anyone who understands evolution, this will come as no surprise because a changed environment means different environmental selectors and driver of evolutionary change will arise, almost by definition, so it would be more surprising if this wasn't reflected in detectable evolution, as least at the genomic level, if not the phenotypic level. The fact that the researchers found evidence that red leaves had arisen several times with different genetic changes is nothing more than would be expected of a widespread species where environmental selctors will vary from plavc to place and genetic drift anfd founder effects will mean they have different dombinations of genes to operate on.
Prevalence of impervious surface and resulting higher temperatures in urban areas, known as urban heat islands, comprises prominent characteristics in global cities. However, it is not known whether and how urban plants adapt to such heat stress. This study focused on Oxalis corniculata, which has intraspecific polymorphism in leaf color (green and red) and examined whether the leaf color variation is associated with urban heat stress. Field observations revealed that green-leaved plants were dominant in green habitats, and red-leaved individuals were dominant in urban habitats, at local (<500 meters), landscape (<50 kilometers), and global scales. Growth and photosynthesis experiments demonstrated that red-leaved individuals performed better under heat stress, while green-leaved individuals performed better under nonstressful conditions. Genome-wide SNP analysis suggests that the red leaf may have evolved multiple times from the ancestral green leaf. Overall, the results suggest that the red leaves of O. corniculata observed in cities worldwide are evidence of plant adaptive evolution due to urban heat islands.INTRODUCTION
Fig. 1. The morphology and distribution of green- and red-leaved O. corniculata.
The representative pictures of green- and red-leaved individuals in field environments (A), microscopic image of a section of green and red leaf (B), leaf color distribution of O. corniculata between urban and green space (farmland or green sites) at different research scale local levels (C), landscape level (D), and global level (E). The images on the left show the observation sites at each of the survey scales [for (C), one of the three survey locations]. Images on the right show the proportion of individuals for each leaf color. The top right photo in local level picture (C) has been modified from Google Maps. The five-point scale for leaf color has been dropped by two units to improve visibility (1 and 2 as green and 3, 4, and 5 as red).
Urban environments are human-created habitats that occupy approximately 3% of the world’s total land area and often impose several biotic and abiotic selective pressures on urban organisms (1, 2, 3). These urban ecosystems provide valuable opportunities for understanding the processes and impacts of extreme environmental changes on the rapid evolution of plants (2, 4, 5, 6, 7). Understanding the evolutionary processes that occur in response to environmental stresses in urban areas may be important for understanding the eco-evolutionary dynamics occurring between nature and human societies (8, 9, 10, 11, 12). It may also offer unique opportunity to predict the adaptation of wild and domesticated species in response to extreme environmental conditions, particularly in the face of ongoing and projected global climate change (13, 14).
[…]
Fukano, Yuya; Yamori, Wataru; Misu, Hayata; Sato, Mitsuhiko P.; Shirasawa, Kenta; Tachiki, Yuuya; Uchida, Kei
From green to red: Urban heat stress drives leaf color evolution
Science Advances 9(42) eabq3542. doi: 10.1126/sciadv.abq3542
Copyright: © 2023 The authors.
Published by American Association for the Advancement of Science. Open access.
Reprinted under a Creative Commons Attribution 4.0 International license (CC BY 4.0)
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