Ilona Amos: Could Earth become a world without flowers once again?
In the dim and distant past our planet looked very different than it does now. I'm talking hundreds of millions of years ago, before even I was created.
The landscape was a green haven, carpeted with mosses, lichens, ferns, cycads and conifers in those days. It was not until many more millions of years later that the earliest flowering plants first poked their pretty little heads out of the undergrowth.
Since then, angiosperms, as they are known, have pulled off a stealthy rise to dominate the plant kingdom.
And today they make up around 90 per cent of all living plant species and much of the crops we eat. But how they came to be so successful is considered “one of the most profound mysteries in evolutionary biology”, according to US scientists Kevin Simonin and Adam Roddy.
The answer has foxed experts for centuries, leaving even the famous naturalist Charles Darwin stumped. He described it as “an abominable mystery”. However, Simonin and Roddy believe they have finally worked out the reason why flowering plants were able to thrive and take over the botanical world.
Previous theories had suggested flowering plants rose to dominance through more efficient conversion of sunlight into food, allowing them to outcompete the ferns and other greenery that had once dominated terrestrial ecosystems. But the pair claim there is “strong evidence” it all comes down to genetics – “genome downsizing”, to be precise.
I’m not going to pretend to fully understand how this works but they say smaller genomes permit the construction of smaller cells that allow for greater uptake of carbon dioxide and more efficient production of energy through photosynthesis. They conclude: “Genome downsizing occurred only among the angiosperms, and we propose that it was a necessary prerequisite for rapid growth rates among land plants.”
It’s true that takeover has been a long process, but it goes to show how life on Earth is constantly changing and adapting. It should also serve as a warning for how human activities could affect what happens next.
Most people love flowers – except perhaps those with a serious pollen allergy. They are often things of exquisite beauty and heavenly perfume. Some are delicate, others bold and brassy. We use them as tokens of love and remembrance. They symbolise important celebrations and decorate our homes. They inspire art, poetry, music. We douse ourselves in their scent and name our kids after them as a way of capturing their essence for ourselves.
It’s thought the first organisms we think of as land plants appeared on Earth around 475 million years ago. Various bugs evolved simultaneously, developing co-dependency. Our kind turned up only around 200,000 years ago, but we’ve been making a big impression – particularly in the last couple of centuries with industrialisation and the resulting damage to the environment.
We’re already experiencing record-breaking temperatures year on year and witnessing the effects of climate change on everything from the fish in our oceans to the birds in the skies. Our need to feed a growing population is seeing more forests felled and an increase in pesticide use that is killing bees and other important pollinating insects. It would be a tragedy beyond compare if we didn’t have flowers. The world would be a dull and lifeless place.