BIODIVERSITY LOSS AFFECTS HUMAN HEALTH

1. Context 

2. Key points

• Bright reds, yellows and blues the colour of poison dart frogs offer a stark warning to curious predators.
• The amphibians are toxic. when eaten, the chemicals on their skin can cause convulsions, muscle contractions and even death. For humans, these colours mean something more hopeful.
• Those same poisonous chemicals could provide the key to medications that treat infections now resistant to the antibiotics, we have already developed.
• Poison dart frogs have important medical compounds that are good anaesthetics.
• They have good antibiotics that are on their skin that we are using now. And many that have not even been discovered or commercialised yet.

3. The basis for much-needed medicine

• Natural compounds found in frogs, plants and many other species provide the basis for many of our medicines.
• Paclitaxel, a drug used to treat cancer, for example, is derived from the bark of the Pacific yew tree and ziconotide a drug that is used to treat severe pain comes from cone snails.
• Around 70 per cent of cancer medications are based on nature, according to the UN's Intergovernmental SciencePolicy Platform on Biodiversity and Ecosystem Services (IPBES).
• But biodiversity, which includes the plants, animals, fungi and bacteria found on Earth is disappearing and so, too are the possibilities they hold.
• Climate change and chytrid fungus have decimated our frog populations and led to a large number of extinctions.
• Chytrid fungus causes a disease in amphibians that has wiped out as many as 90 species.
• Maybe we don't need so many different hundreds of species of frog. But on another hand, that potential kind of treasure trove is still there.

4. Human-driven extinction

• Around 1 million animal and plant species are currently estimated to be threatened with extinction, according to a 2019 report published by IPBES, although estimates vary wildly.
• Experts say species are disappearing 1, 000 to 10, 000 times faster than the normal rate of extinction and humans are to blame.
• The two things that threaten biodiversity the most at the moment are overharvesting and land conversion.
• That's not just clearance of land for livestock to graze, but also clearance of land for food and clearance of land for food and clearance of oceans.

• Human-driven climate change is also having an impact. Growing carbon dioxide levels are leading to increased ocean acidification, bleaching corals and destroying vast habitats. 
• Rising temperatures and unsustainable harvesting are also pushing some plant species to the edge of extinction.

5. Traditional medicine

• While the loss of biodiversity is making it more difficult to discover new medications, it is also affecting how communities access traditional medicine.
• An estimated 4 billion people still rely primarily on natural remedies to heal themselves whether it is using latex from fig trees to treat intestinal parasites in the Amazon or neem oil to treat skin disorders in India.
• They don't go to the pharmacy, they go to what they have collected and stored. So when those plants are difficult to access, that's putting their health at risk.
• Around 40 per cent of the world's plant species are threatened with extinction, according to a report published by the Royal Botanic Gardens Kew in London, which is home to one of the most diverse botanical collections in the world.
• Among the threatened plants are 723 species that are used medicinally.
• The Pacific yew tree the source of paclitaxel, the chemotherapy drug, is now classified as near threatened under the IUCN Red List, which tracks the status of different species.

6. The Future of drug discovery

• When thinking about drug discovery, it's hard to know exactly what humans stand to lose through the loss of species that make up a diverse natural world.
• There is still so much to investigate. The ocean for example remains still largely undiscovered.
• Scientists are looking to chemicals produced by sponges to provide treatment for cancers, for example. But it is more complex than simply finding and examining single species.
• Gerwick is investigating the symbiotic relationship between the weaver shrimp and cyanobacteria.
• The shrimps weave the bacteria into nests, which protect them from predators because of the toxic molecules the bacteria produce molecules that have the potential as a treatment for pancreatic cancer in humans.
• So the bacterium produces these compounds and the shrimp derives benefit from it and maybe humans do as well.
• If we lose biodiversity we are losing access to molecules and some of those molecules might be compounds that would save the life of one of our children from an infectious disease, from cancer.

7. Nature health equals human health

• Humans are almost completely dependent on the natural world to stay healthy.
• Beyond drug discovery, we rely on trees to take pollutants like carbon dioxide, out of the air.
• We need working wetlands to keep the water clean and we need insects to pollinate our crops to provide us with food.
• Measures are being taken to protect biodiversity and reverse the loss.
• In December, 188 governments agreed to take action to put 30 per cent of the planet under protection by 2030.
• But it is not clear whether it will be sufficient and come quickly enough.