Where would we be without flowers? Rather, where would life itself be without flowers? Here, apart from the literal meaning, we celebrate every aspect of life (and death) with flowers. A marriage ceremony? The bouquet of flowers will not leave the bride’s hands. Got a relative in hospital? Give him or her some flowers. A friend’s grandfather passed away? Time to get a floral wreath. Just need to relax at home? Look at your flower arrangement or even a picture of a bunch of flowers for a while.
We love flowers due to their smell, colour, beauty and texture. Well, even flowers that smell like death are popular, such as the rare ‘corpse flower’ that blooms just once every few years, emanating the stench of rotting flesh. Moreover, growing flowers and gardening have become major hobbies that help people to relax and appreciate Nature. Flowers are a big business too - Sri Lanka is a top exporter of cut flowers.
Flowers have long held the fascination of humans, but in evolutionary terms they are a relatively recent arrival, first bursting into bloom between ‘just’ 140 and 250 million years ago. Today, there are around 350,000 species of flowering plants and many hybrid varieties introduced by Man. Flowers are the key to life in all their manifestations, and life on Earth may have evolved drastically differently if they did not come into being. Flowers and their pollinating animal partners (mainly insects such as bees) are responsible for propagating much of the organic life on the planet. In fact, flowering plants represent 90% of all land plants and are vital to the survival of terrestrial life.
Ancestor
European botanists have now determined what the single ancestor of all modern flowers looked like, using the largest data set of features from living flowers ever assembled. The first angiosperm, or flowering plant, had a simple arrangement of layered petals and contained both male and female reproductive organs, according to the study. The authors of the study show that the ancestral flower was a hermaphrodite. This means that early flowering plants could reproduce both, as a male and a female. Combined sexes can be advantageous when colonizing new environments as a single individual can be its own mate, and indeed many plant species colonizing remote oceanic islands even now tend to be hermaphrodite. The combination of sexes also helped early flowering plants to out-compete their rivals.
The scientists reconstructed the first flower on computer using combined models of flower evolution with information from a huge database of present-day floral traits. In outward appearance, the ancient flower looks similar to a water lily or a Magnolia. Its key feature is multiple whorls of petal-like structures arranged in sets of three. A picture of the reconstructed primeval flower appears in the latest issue of the journal, Nature Communications.
Hervé Sauquet from France’s Université Paris-Sud, one of the authors of the academic paper behind the discovery, said: “It is a highly imperfect flower but I find it rather attractive.” The news has naturally excited botanists and biologists around the world.
He says, the origin of flowers was one of the great mysteries of science and scientists probably know more about the origin of the moon than they do about the origin of flowers. The researchers wrote: “In spite of similarities with some extant (present day) flowers, there is no living species that share this exact combination of characters.” This ancestral plant, alive sometime between 250m and 140m years ago, produced the first flowers at a time when the planet was warmer, and richer in oxygen and greenhouse gases, than today.
There are many questions yet to be answered about the first primitive flower, such as how it was coloured and how it was pollinated. It will not be easy to answer these questions in the absence of any fossilized evidence (as in the case of dinosaurs) but scientists should be able to decipher more information about the first flower in the next few years. A fossil discovery will be helpful, but flowers being so fragile, such a discovery is unlikely if not improbable.
The question whether pollen or pollinators came first is a repeat of the ‘chicken and egg’ dilemma. But, the first insects capable of pollinating a flower plant appear to have evolved around 100 million years ago. Amber from the Cretaceous period found in Spain recently revealed the first ever fossil record of insect pollination. Scientists discovered and studied with X-rays a specimen of a tiny insect covered with pollen grains. This is the first record of pollen transport and social behaviour in this group of animals. (Only amber can preserve behavioural features like pollination in such rich detail over millions of years. If you have seen Steven Spielberg’s Jurassic Park, you will recall the scene where scientists extract dinosaur DNA from an insect that had bitten a dinosaur before being trapped in amber).
Today, more than 80 percent of plant species rely on insects to transport pollen from male to female flower parts. Pollination is best known in flowering plants, but also exists in gymnosperms, seed-producing plants like conifers. Although the most popular group of pollinator insects are bees and butterflies, lesser-known species of flies and beetles have co-evolved with plants, transporting pollen and in return for this effort rewarded with food. It is believed that some flowers have evolved bright colours that are attractive to their insect friends. Some flowers have colours and arrangements that are invisible to the human eye but are visible to insects.
Extinct
We have all heard the story that life would come to an end pretty soon if bees were to become extinct, but flowers can have many indirect benefits on our life. Many flower extracts are already used in beauty products and medicinal preparations. Now, Scientists in Chile have discovered molecules in two species of Antarctic flowers that protect the plants from solar radiation and could potentially be used in products such as, sunscreen for humans and protection for vulnerable crops. Researchers at the University of Santiago, investigating the properties of Antarctic plants grown under controlled conditions found that Colobanthus quitensis (pearlwort) and Deschampsia antarctica (hair grass) could tolerate high levels of ultraviolet radiation.
Flowers not only embellish our world and our lives, but also have the potential to make our lives healthier. They are much older than humans on the evolutionary scale and are still evolving, sometimes with our help.
Studying the origin of flowers will help us to learn more about the evolutionary trends of these enigmatic creations of Nature without which all life on Earth would eventually perish.