On Earth, an ecosystem has evolved that includes a wide variety of animals, plants, protists, fungi, bacteria, and Archaea. Earth life is diverse and we Homo sapiens are a result of billions of years of biological evolution that has left behind clues of its transformation in the form of rocks & fossils. The distant ancestors of all modern life evolved in the oceans as the continents began to form, some producing oxygen that filled the atmosphere. More than a billion years ago the remains of microscopic marine organisms began to form the first petroleum oil deposits. The ocean chemistry changed as life advanced and erosion from the expanding continental surface washed minerals into the water. Mineral ingredients concentrated, and marine animals used them to adapt to their changing environment by growing the first skeletons. More than 350 million years ago bones adapted to support body weight as early amphibians crawled on to continental surfaces inhabited by the first forests, which left behind the earliest coal deposits.
Over the last few hundred million years bones continued to evolve to allow organisms to defy gravity. Almost all terrestrial vertebrates (land based animals with spines) hold their spines generally parallel to the Earth, using limbs to support their weight from below. They began on 4 legs and developed senses to better navigate challenging environments. In time, some evolved to balance on 2 legs as bipeds. Bipedalism is not rare in the animal kingdom, but it does require better balance and more muscle control. Humans evolved a unique form of bipedalism by balancing on 2 legs as we hold our spines vertically, causing our bones to continue to evolve to support our weight against gravity in a particularly precarious posture. Many Homo sapien bones, joints and muscles continue to evolve to accommodate our changed orientation…and our postural habits influenced by modern demands.
Our gigantic human brain sits nestled in our skull, atop our vertical spine. This amazing brain is the organ we use to reason, communicate, sense our environment, explore nature, and understand evolution over time. Our brain lets us perceive space and time, and catalog the changes that take place. Amazingly we have gathered enough pieces of four and a half billion years of Earth history to sufficiently allow us to understand the evolution of our planet. We have learned how the planet formed, oceans evolved, continents grew, generations of plankton died to form oil, animals evolved bones that would be fossilized, and forests evolved and formed layers of coal. Later primates would evolve in the forest canopy developing the senses we use to understand our changing environment. Our understanding of Earth history will never be complete, there is too much space and time and too much evidence both lost and found for us to sift through. What we have discovered is that we Homo sapiens are unique because of our upright posture, our ability to imagine, and our capacity to create using the resources of the world we live in. We have learned that everything on our planet is a resource, and have developed products using plants, animals, fungi, protists, bacteria, Archaea, minerals, rocks, and fossils.
Homo sapiens are but one species on a vast tree of life that has produced many organisms, each unique in their own way, and each part of Earth’s evolving ecosystem. Relatively recently in Earth history some Homo sapiens began to believe they could dominate nature, and became the first organisms to attempt to divorce themselves from the environment. They pretend we are separate from the environment that we evolved within, and that we continue to rely on. Our attempt to control nature has only led to the realization that our comprehension of the complexities of the environment remains limited relative to the immensity of Earth time. We actually have no control over the planetary environment, but we do influence it and it in turn influences us. With our growing population and use of Earth resources we affect the entire ecosystem as we steer the trend of environmental change, unconsciously or consciously.
Homo sapiens interaction with the planet is unique, because we are increasingly aware of how we affect and are affected by Earth’s environment. We have changed the chemistry of the atmosphere, the temperature of the oceans, the reflectivity of the continents, and the diversity of the ecosystem. Though we have made choices that are resulting in environmental destruction and instability, we can choose to interact in ways that lead to stability and balance for ourselves and the rest of the species that are part of Earth’s ecosystem. Our present and future choices require that we resume our role within the ecosystem, we see ourselves as part of the environment, and we choose to be part of nature. It is likely that we are the first Earth organisms to become aware of our place in the tree of life and Earth history. For the first time in Earth history a species has the opportunity to consciously shape the future of planet Earth, with the knowledge that we are part of and dependent on its/our ever changing environment.
One environmentally sustainable decision that each of us can make is to avoid single use plastics. Since 2011 July has been “plastic free” month. A challenge to refuse to use single-use plastics for one month, and hopefully that will change our consumer habits for the rest of our lives. Plastics production is unhealthy for the ecosystem and our bodies in every way, and should be used only when necessary. In honor of Plastic Free July I have created a webpage on my Earth Education website entitled “Sustainable Choices”. I provide links to websites that help us make environmentally responsible consumer decisions, and I provide information about choosing sustainable materials with an emphasis on avoiding plastics because they are made from crude oil, quite literally the remains of dead organisms of the past. While we dig up the past to better understand how Earth has changed, removing the remains of ecosystems of the past and turning it into fuel, bags, toys, dishes, food wraps, and water bottles is not our best use of Earth resources. Homo sapiens are resourceful, but we need to be more discerning about which resources we use. There are so many other choices that positively influence our health and environmental sustainability, and therefore establish our conscious decision to be invested in Earth’s environmental stability and supportive of planetary ecosystem evolution.
