Parisian pansy
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Context
- In the first evidence of rapid evolution, scientists have discovered that a flower Parisian pansy is producing less nectar and smaller flowers to attract fewer pollinators.
Viola arvensis
- Viola arvensis is a species of violet known by the common name field pansy.
- It is native to Europe, western Asia, and North Africa, and it is known on other continents as an introduced species and a weed of disturbed and cultivated areas.
- It is an herbaceous annual plant with serrated leaves, and usually flowers with white all over, except the bottom petal and dehiscent capsules. It reproduces by seed. It grows 20 centimetres tall.
- Parisian pansies specifically are flowers growing in Paris, France.
Recent Research
- Field pansy produces less nectar and smaller flowers to attract fewer pollinators.
- Field pansy is self-pollinating, as indicated by the research.
- Ongoing convergent evolution of a selfing-syndrome threatens plant-pollinator interactions.
- The study found that flowers of the wild pansy variety grown in four locations in Paris produced 20 percent less nectar and were 10 percent smaller.
- The scientists compared the growth of the flowers grown in the same fields with seeds from 20-30 years ago. Insects also frequented the fields where the flowers grew.
- Scientists discovered that the plant evolved to self-pollinate to attract fewer pollinators due to the decreasing availability of insects.
- This study is the first to show convergent evolution across populations, reduced rewarding trait, and reduced attractiveness.
- Self-pollination is the process by which plants reproduce themselves.
- The behavior is contrary to the convention of angiosperms, which rely on insects to pollinate to reproduce — an interconnected relationship in nature.
- Plants produce nectar to attract insects, which collect nectar for food and transport pollen between plants in nature. The interlinked give-and-take relationship has evolved over 100 million years of coevolution.
- The researchers used the “resurrection ecology” method, wherein they planted seeds from the 1990s and 2000s, which were 20-30 years old, against their contemporary descendants from 2021. The seeds were planted in four locations across Paris, growing about 4,000 plants.
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Resurrection ecology (RE) Resurrection ecology (RE) provides science with living historic organisms (as opposed to, e.g., museum specimens or fossil DNA) that can be raised in laboratory or semi‐laboratory (e.g., experimental plots) conditions in order to characterize phenotypic evolution and the underlying genetic architecture, using temporal snapshots of the same population with the same genetic background. Convergent Evolution Convergent evolution is the independent evolution of similar features in species of different periods or epochs in time. Convergent evolution creates analogous structures that have similar form or function but were not present in the last common ancestor of those groups. The cladistic term for the same phenomenon is homoplasy. The recurrent evolution of flight is a classic example, as flying insects, birds, pterosaurs, and bats have independently evolved the useful capacity of flight. Functionally similar features that have arisen through convergent evolution are analogous, whereas homologous structures or traits have a common origin but can have dissimilar functions. Bird, bat, and pterosaur wings are analogous structures, but their forelimbs are homologous, sharing an ancestral state despite serving different functions. The opposite of convergence is divergent evolution, where related species evolve different traits. Convergent evolution is similar to parallel evolution, which occurs when two independent species evolve in the same direction and thus independently acquire similar characteristics; for instance, gliding frogs have evolved in parallel from multiple types of tree frog. Many instances of convergent evolution are known in plants, including the repeated development of C4 photosynthesis, seed dispersal by fleshy fruits adapted to be eaten by animals, and carnivory. Convergent evolution is also observed in non-biological structures. |
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PRACTICE QUESTION Q. What do you understand by the concept of Resurrection Ecology? Explain. Give a comparative analysis of Convergent and Divergent Evolution. |
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