Bio-diversity, Co-evolution: Animals and plants that have evolved together to benefit from one another

You can write several books on this topic as we have vast amounts of co-evolution knowledge now. However, I will answer briefly by giving only a few examples.

Ecosystems are special in the sense that plants and animals evolve together in particular areas of Earth, so it is not surprising that there are many complex plant-animal relationships. This process of interdependent evolution of two or more species is called coevolution.

Co-evolution is the mutual relationship between two interacting organisms where both the organisms are unable to survive in the absence of the other.

The co-evolution of fig and wasp as a pollination is highly linked with one another. Fig and wasp is a good example of mutualism and coevolution between a plant species and an animal species.The female wasp uses the fruit and fig for oviposition/egg laying uses seeds within the fruit developing seeds for nourishing its larvae. In return the wasp pollinates the fig inflorescence the given fig species can be pollinated only by its partner wasp species & no other species.

Here are some other examples of animals that have evolved in relation to plants:

Humming bird beaks evolved in response to flower structures

Image source: Bird life international

Hummingbirds and honeycreepers: These birds have beaks that have evolved to exploit flowers, and can be so specialized that they can only be effective on a small group of flowers. Hummingbirds and honeycreepers, for example, have distinctive beaks that have evolved to exploit flowers. Often, a beak may be so specialized that it is only effective on a small group of flowers.

So Hummingbirds and other sap-sucking birds evolved with the flowers they feed on for the primary energy fix.

Pollinators: These animals have also evolved to take advantage of the flowers.

Animals have many different adaptations that were caused through speciation and as a response to environmental changes.

The pollinators, in turn, have evolved to take advantage of the flowers.

Some relationships are beneficial to both parties, while others have a clear benefit for one at the expense, or even death, of the other. Four important plant-animal interactions are highlighted here: plant-herbivore, plant-pollinator, plant-disperser, and other examples of mutualism (2).

Herbivory is an interaction in which a plant or portions of the plant are consumed by an animal. At the microscopic scale, herbivory includes the bacteria and fungi that cause disease as they feed on plant tissue. Microbes that break down dead plant tissue are also specialized herbivores. Browsers and grazers, from aphids and caterpillars to deer and bison, are more familiar herbivores. Even insects and animals that eat seeds are considered herbivores.

For instance , koalas and eucalyptus trees evolved together so koalas can survive and propagate on eucalyptus leaves, where few other animals can.

Harvester ants gather grasses which they cultivate, farming fungus. They then eat the fungi.

Some herbivores consume entire plants, or enough to kill them. Others only eat a portion of the plant, and so the plant can recover. The plant-herbivore relationship traditionally has been seen as lopsided, with the animal as the beneficiary and the plant as the loser. Current research, however, is revealing that herbivory has some potential benefits to plants too. One example is canopy grazing by insects, which allows more light to penetrate into the lower layers of the forest. Gypsy moth grazing on canopy trees in some areas of Mountains, for instance, has resulted in more light penetration and therefore a more diverse and productive ground layer.

Herbivores Image source: National geographic education

Many plants depend on animals for pollination. Insects, birds, even bats are important for perpetuating plants. The flowers of these plants evolved in concert with their pollinators, and their form reflects the form and habits of their pollinators. Bee-pollinated plants are often irregular in shape, with a lip that acts as a landing pad to facilitate the bee's entry into the flower. Butterfly-pollinated flowers are often broad and flat, like helicopter pads. The flowers of many plants are brightly coloured to attract their insect pollinators, and many offer nectar as an enticement. Hummingbirds, with their long beaks, pollinate tubular flowers. Bats require open flowers with room for their wings, such as those of the saguaro cactus. In the tropics, birds and bats take the place of insects as pollinators. Hummingbirds and honeycreepers, for example, have distinctive beaks that have evolved to exploit flowers. Often, a beak may be so specialized that it is only effective on a small group of flowers (2).

The pollinators, in turn, have evolved to take advantage of the flowers. A successful pollinator typically develops and has good colour vision, a good memory for finding flowers, and a proboscis, or tongue, for attaining nectar.

Animal pollination has obvious advantages for plants. Many pollinators cover great distances, which insures genetic diversity through outcrossing, or the transfer of pollen to unrelated individuals. The pollinator benefits as well by gaining access to a source of food. The relationship of pollinator plant is an example of mutualism.

No two plants can occupy the same spot. In order to have room to grow, seeds must be dispersed away from the parent plant. Seed dispersal is accomplished by a variety of means, including wind, water, and animals. Animal dispersal is accomplished by two different methods: ingestion and hitch-hiking. Animals consume a wide variety of fruits, and in so doing disperse the seeds in their droppings. Many seeds benefit not only from the dispersal, but the trip through the intestine as well. Specifically developed digestive acids scarify seeds, helping them to break out of thick seed coats.

Mutualism is an obligate interaction between organisms that requires contributions from both organisms and in which both benefit. There are many examples in nature. Pollination and dispersal, discussed above, are mutualistic because both plant and pollinator or disperser benefit from the relationship.

The mutually beneficial relationship between algae and modern corals — which provides algae with shelter, gives coral reefs their colours and supplies both organisms with nutrients — began more than 210 million years ago, according to a new study by an international team of scientists.

Corals have evolved a mutualistic relationship with microscopic algae called zooxanthellae, where both species benefit from each other's presence (1):

Corals ; Image source: Wikipedia

Corals: Corals provide shelter for the algae, as well as compounds that the algae need for photosynthesis. The algae produce carbohydrates that the corals use for food, as well as oxygen. The algae also help the coral remove waste. Corals can get up to 90% of their energy needs from the photosynthetic products of the algae, which they use to survive and build their skeletons. This stability is critical to the survival of corals, and when they lose their algae, they often bleach out and die.

Algae: The algae gain shelter, carbon dioxide, and nutrients from the corals.

That this symbiotic relationship arose during a time of massive worldwide coral-reef expansion suggests that the interconnection of algae and coral is crucial for the health of coral reefs, which provide habitat for roughly one-fourth of all marine life. Reefs are threatened by a trend in ocean warming that has caused corals to expel algae and turn white, a process called coral bleaching.

A study found strong evidence of this coral-algae relationship in fossilized coral skeletons dating back more than 210 million years to the late Triassic period.

Research found that the corals inhabited nutrient-poor marine environments — not unlike today’s subtropical waters — where algae-coral symbiosis played a major role in driving reef development.

The onset of symbiosis with algae was highly profitable for corals. It allowed them to survive in very nutrient-poor waters, and at the same time grow and expand.

Algae belonging to the group known as dinoflagellates live inside the corals’ tissues. The algae use photosynthesis to produce nutrients, many of which they pass to the corals’ cells. The corals in turn emit waste products in the form of ammonium, which the algae consume as a nutrient.

This relationship keeps the nutrients recycling within the coral rather than drifting away in ocean currents and can greatly increase the coral’s food supply. Symbiosis also helps build reefs — corals that host algae can deposit calcium carbonate, the hard skeleton that forms the reefs, up to 10 times faster than non-symbiotic corals.

So all ecosystems have some very good examples of co-evolution. That is why we stress that biodiversity is important.

Biodiversity is the sum of all life on earth. Every single individual lifeform from the smallest bacteria in the soil to the largest whale in the sea, is a component of Earth’s biodiversity. But biodiversity doesn’t stop at the individual. Biodiversity is also the relationships between these lifeforms and their habitat. That includes the relationship between plankton and whales that help produce oxygen in the atmosphere, seeds and rhinos that help plant forests, and bacteria and plants that change the chemistry of soils.

Animals and plants that depend on one another and finally the human beings that depend on the entire eco systems of our planet. Each and every one of these lifeforms and their surroundings contribute something important to the survival of living beings and our environment.

Biodiversity; Image source: EuroKids

Earth’s biodiversity is the very basis for our own survival (3). This is demonstrated repeatedly, across the planet, at the macro and microscopic scale. Without plants, there would be no oxygen. Without bees, many of our crops would vanish. Other benefits of biodiversity are even more fundamental. The hardwood trees in the rainforests that are our most effective above-ground carbon sinks are also the product of the relationship between seeds and the fruit-eating animals that eat them. Trees are up to 500x more likely to germinate when the seeds have first passed through the digestion system of a bat, monkey, or elephant.

Microscopic biodiversity in our soils creates the chemical conditions necessary for healthy, abundant, and sustainable crops. Many new medicines are found in nature, including cancer fighting fungi and pain killing tree resins.

Economically, the services provided by biodiversity are estimated to be double the world’s annual GDP.

So it is very difficult for living beings to survive without co-evolution and biodiversity. Realize that.

Footnotes:

1. https://www.princeton.edu/news/2016/11/02/when-corals-met-algae-sym...

2. https://www.bbg.org/article/plant_animal_relationships#:~:text=Humm....

3. What is Biodiversity?