Why Should We Protect Wildlife?
What Biodiversity Does For UsPosted on: December 30th, 2020
Sheltering-in-Place Blog Entry #36
In a previous blog, we talked about the value of biodiversity, a term we use as a giant bucket for all of the plants, animals, microbes, fungi, and even viruses that comprise what we call life on Earth. Our planet is certainly unique among the known universe, although we have theorized that there can be many Earth-like planets out there among the billions of celestial bodies. However, even though scientists are right in that many planets in the known universe could support “life” as we know it (and life as we can’t even imagine), Earth is the only planet we know, the one where we live, and the one that is under our management. So, how well do we know life on Earth and how much humans have benefitted from this life throughout our existence?
Our current knowledge of the planet’s biodiversity is quite incomplete and deficient. Of the estimated 8.5 or 9 million species on Earth — and this is quite a problematic and imperfect number to arrive at —we have barely described and named around 1.3 to 1.5 million species. But wait, many of these names are probably duplicate for some species (called synonyms), thanks to improvements in technology such as DNA barcoding, whole-genome studies, and more. These advancements give us more information than past scientists had. Many species descriptions relied solely on morphology, the look and details of the shape, color, and physical structure of organisms.
These days we look at species more comprehensively and include data about their DNA, behavior, geographic distribution, physiology, and more. Regardless of these fine points, the number of species on Earth and how many we still need to discover is a complex and vexing topic for scientists to elucidate. It’s also a giant puzzle for people to understand and use to make decisions. In short, there are many more species on Earth that are entirely unknown to us than are known and named species. If we don’t know them, can’t recognize them, and don’t know anything about them, we can’t use them, protect them, or make decisions about sustaining them over time.
In this essay, I want to focus on the benefits humans have obtained from even this poorly known state of our biodiversity. I’ll also take a particular sharper focus on what we call “wildlife.”
Medicinal compounds from nature are perhaps the most poignant and clear example of a service that nature provides humans. The number of medicines and drugs that have been developed from our accumulated knowledge of plant and animal species is vast. For example, many alkaloids (toxic compounds that plants use as defense mechanisms) have been converted into medicines, such as atropine, scopolamine, morphine, quinine, and the cancer-treating vinblastine and vincristine. Caffeine and cocaine are also alkaloids of broad use, one legal and common, and the other recreational but illegal. Also, several glycosides, such as digoxin and digitoxin, are used to treat cardiac conditions. Other compounds that plants use for protection include polyphenols (phytoestrogens, astringents, and punicalagins) that have medicinal and dietary applications. Finally, terpenes, found in several traditional medicinal plants and conifers, are used in essential oils, aromatherapy, antiseptics, and vermifuges (to treat intestinal worms).
Animal-derived medicines are also abundant and include sources that are surprising and even counterintuitive. Many animals, such as snakes and spiders, use venoms to subjugate their prey. These venoms have been recruited by medical professionals and pharmacologists to treat several conditions. For example, we have used heparin, insulin, and pituitary hormones in medicine for a couple of hundred years. Extracts from animal pancreases are still used to treat diabetes. Captopril, derived from the venom of the Brazilian pit viper Bothrops jararaca, is used today to treat heart failure and infarction. Other compounds derived from different species are commonly used as well. For example, leeches, Hirudo medicinalis, were used since ancient times for a procedure called “bloodletting,” which, thank goodness, is no longer practiced. However, the saliva of leeches contains an anticoagulant compound called hirudin that is used where heparin is not advisable as in tissue grafts and cosmetic surgery. Other examples include:
- The saliva of Gila monsters, Heloderma suspectum, is used to treat diabetes mellitus.
- Cytarabine extracted from marine sponges is used in some types of chemotherapies to treat leukemia.
- Ursodiol, obtained from the bile of bears and other mammals, is used in treating cirrhosis. Tebinicline, extracted from some South American poison dart frogs, is used as an analgesic.
Finally, and incredibly timely, the stunning blue blood of four species of horseshoe crabs, the Asian tri-spine horseshoe crab (Tachypleus tridentatus), the coastal horseshoe crab (Tachypleus gigas) and the mangrove horseshoe crab (Carcinoscorpius rotundicauda), and one closer to home, the American horseshoe crab (Limulus polyphemus) are essential players in the production of all kinds of vaccines, including the newest COVID-19 vaccines. The unusual blood of this ancient species (they are older than dinosaurs!) is used to test the safety of these life-preserving medications. The number of animal-sourced chemicals continues to grow every day.
Plants and animals are not the only organisms that have produced useful and often life-saving compounds. Fungi and bacteria are essential players in preserving human lives. Extracts and compounds from various fungi have been used in the successful development of drugs such as antibiotics, anti-cancer drugs, fungicides, and psychotropic and immunosuppressant medicines. One promising antifungal compound called Selvamicin was recently discovered in my former workplace, the La Selva Biological Station in Costa Rica. It is produced by a symbiotic bacterium that lives on the cuticle of some tiny fungus-growing rainforest ants. The use of chemicals produced by bacteria and fungi as medicines is a growing area of research.
But nature and wildlife are more than just sources of useful medicinal compounds. Almost all of our animal-based foods can be traced to some wild species domesticated and manipulated through artificial selection. The wild ancestors of cows, sheep, pigs, chickens, and fish play critical roles in ecosystems’ stability, providing an essential set of “Ecosystem Services” (Google that term; it is super important). Many of our crops rely on wildlife to achieve pollination (bees and bats, for example). Without healthy pollinator populations, some of our most important agricultural products will eventually disappear from our tables. Healthy ecosystems can help prevent the transmission of animal-borne diseases to humans, regulate the effects of pollution and climate change, and provide an unending source of raw materials to develop new medicines and foods. A healthy ecosystem cannot exist without a diverse and stable complement of its parts, plants, animals, soil microbes, and fungi (decomposers). Carbon sequestration, the extraction of atmospheric carbon carried out by terrestrial and aquatic plants and algae, is an essential ecosystem service that is needed today more than ever. Adopting a wildlife conservation philosophy is one of the most important endeavors that humans can engage in to guarantee a healthy environment and future. The conservation of the remaining wild habitats and wildlife, including the restoration and sound management of existing ecosystems, is one of humanity’s most critical challenges today. At Lindsay, we are committed to pursuing wildlife conservation in all its forms. Are you with us?
Carlos L. de la Rosa