Evolution Under Pressure: How We Change Nature and How Nature Changes Us
Introduction Have you ever looked in the mirror and wondered how you could possibly be related to a fish Or a spider Or even one of those blobby-looking amoebas you’ve seen swimming in pond water under the microscope Maybe you’ve watched your brother eat a banana and thought he looked a lot like a monkey Or tried to follow your sister up a tree and wished you were more of a monkey yourself If every creature on Earth came from the same ancestor why are we all so differ ent If we’re all related to one another why do just some of us thrive in the water And how come only some of us can fly Each of us has our strengths and weaknesses which allow us to coexist within the same ecosystem We can’t all live in the trees for example or they would get crowded But only humans have figured out how to exist in almost every part of the world even in space by doing things like cutting down trees growing crops building cities and inventing new ways to travel We’re the only ones who have altered our natural environment on purpose so it’s better suited to us rather than adapting to make us better suited to it How does this affect plant and animal interaction What impact does it have on our shared environment 1
Understanding what evolution is and isn’t is helpful in trying to answer these questions The theory of evolution based on natural selection is a good place to start But to really understand our role on Earth and the effect humans have had on the evolution of all other species including ourselves we can also look at the idea of not-so-natural selection What do animals like hornless rhinos porky pigs peppered moths and anole lizards have in common They’re all good examples of not-so-natural selection showing us how hunting farming inventing and even moving to the city can have a huge impact on other animals None of these human activities are bad We’ve always had an impact on other creatures just like other creatures have an impact on us The problem is through not-so-natural selection human activity has had a bigger impact on the environment and the creatures within it We’ve changed the way the world works interrupting the natural evolution of almost everything and pretty quickly So what now It’s not like we can go back in time and un-invent things And no one wants to go back to a time when we didn’t live such a comfortable life How do we decrease the impact of human activity in a way that works for all creatures How do we exist as part of the large tree of life without breaking too many branches 2 EVOLUTION UNDER PRESSURE
To start we’ll take a quick trip back to the beginning and look at our own evolution How did we start hunting farming and building factories and cities How have these activities changed as humans have evolved Then we’ll look at some specific characteristics from horns and feet to appearance and attitude to understand how not-so-natural selection has interrupted the evolution of certain animals Looking forward we need to be more aware of where we’ve been and where we’re going It’s not too late for humans to make choices that go beyond what’s best for us and consider what’s best for all of us from amoebas spiders and moths to rhinos lizards pigs and humans Humans might be significantly different than every other crea ture on the planet But that doesn’t mean we aren’t dependent on our fellow creatures for survival Every living creature needs a healthy ecosystem to thrive And as the animal with the largest impact it’s time for humans to ensure there’s enough room and trees for everyone Because it’s about all of us we’re all interconnected INTRODUCTION 3
