Scientists have named the nine most intriguing mysteries of planet Earth

From the depths of the Amazon rainforest to the deserts of Antarctica, huge unanswered questions about life on Earth remain. The Guardian asked leading scientists and conservationists: What is something you’d like to know about the planet that remains a mystery?

* How many species are there on Earth?

“How many different species of animals do we share the planet with? Estimates range from as little as 3 million to as much as 100 million, and there’s little indication that we’re getting any closer to an answer.” – says Professor Andy Purvis – researcher at the Natural History Museum and co-author of the UN Global Planet Assessment 2019

* Go back 540 million years to see the “biological big bang”

“As an evolutionary biologist,” says evolutionary biologist Dr. Corrie Moreau of Cornell University, “I would like to use a time machine to go back to the Cambrian explosion, when most of the major groups of animals first appeared in the fossil record, to understand why this short period led to to the truly rapid growth of most animal groups, and why some, such as trilobites [вымершие морские членистоногие]didn’t survive.”

* Could some of the smallest life forms help prevent the climate crisis?

“Just as we humans rely on our gut microbiome for good digestion, the dirt under our feet contains countless bacteria, fungi and viruses that affect the health of the soil and the plants that grow in it,” says senior lecturer at Grantham Institute at Imperial College London, Dr. Bonnie Waring. “Because most of these organisms cannot be cultured in the laboratory, we know very little about their ecology. However, the presence of certain microbes can help trees grow three times faster. Could these ‘helpful microbes’ be some of our best allies in the fight against climate change and food security?”

* What is the total biodiversity of the Amazon or Congo rainforests?

“I would like to understand all the diversity in a tiny piece of rainforest measuring about 100 by 100 meters: how many species live or pass through there, how they interact with each other, how old they are, where they came from, what they do,” shares his scientific dreams Director of Science at the Royal Botanic Gardens, Kew, Professor Alexander Antonelli. “Beyond the scientific insights it would give us, I hope it would help convince people of the extreme complexity and value of ecosystems that have taken millennia to build, and that protecting what we have left is always a better choice than destroying and recovery attempts later.”

* How do animals affect the functioning of the Earth?

“How do animals shape the appearance and functioning of ecosystems? asks Yadvinder Malhi, professor of ecosystem sciences at Oxford University. “We know they do this in some well-publicized ways, like pollination or seed dispersal, but there are many subtle ways—like nutrient cycling, selective plant eating, intricate webs of predators and prey—that are poorly understood but continually surprising.” . Just last month I learned that spiders determine where plants grow and ecosystems recover after volcanic eruptions by trapping seeds in their webs. And ultimately, how important is this animal’s impact on the biome or global level? How much do animals influence the functioning of planet Earth?”

* What will happen to the Gulf Stream?

“If I had to know one thing that remains uncertain at the moment, it is whether and when the Gulf Stream will suddenly stop, completely changing the climate in Europe, causing a sharp drop in temperatures – with potentially catastrophic consequences for the water supply. and food security – while the rest of Europe is baking the planet due to man-made climate change,” says Sir Robert Watson, one of Britain’s most eminent climate scientists.

* Do universal rules regulate the evolution of plants and animals?

“Organisms with very different ancestors (including both animals and plants) seem to follow a limited number of common ‘styles,’” says Sandra Mirna Diaz, a professor of ecology at the National University of Cordoba in Argentina. – What are the general, simple rules that determine the way they are “combined”, and what makes some of these styles so much more successful on Earth than others? And if such rules exist, are they the same for animals and plants?”

* How many people could the Earth feed?

“The only thing I would like to know is how many more people can the Earth hold? says Dr Gladys Kalema-Zikusoka, a Ugandan wildlife veterinarian and conservation pioneer. – At the current pace, it will take only 10 years for another 1 billion people to appear on the planet. We are already witnessing the devastating consequences of unsustainable population growth as more people destroy pristine habitats to meet food and other basic needs, leading to climate change and more frequent outbreaks of zoonotic diseases and pandemics. If we can live in balance, health and harmony with nature, how many more people can the Earth accommodate?”

* Which species are adapting to the climate crisis and which are not?

“What are the limits of species adaptation and why? We know that climate is changing and species are adapting, but we don’t understand what the limits are or why they change. Which species will not adapt quickly enough and at what point? Which ones will adapt and thrive – and what determines those responses? What can we as a society do to help species adapt? These are fundamental questions whose answers will determine what the natural world will look like in the future, but which also provide profound insight into how biology works and evolves,” says Sir Patrick Vallance, former chief scientific adviser to the UK government and chairman of the Museum’s board of trustees. natural history.