Posts Tagged ‘evolution’
Evolutionary biology is not a slow-moving science. Just last month a new species of hominid (Homo naledi) was unveiled at a news conference in South Africa. When did modern humans branch off as an independent species? What have been our most important adaptations? And, most importantly, what is the next evolutionary step for humanity? We reached out and spoke to five of the foremost experts on human evolution, who shared their expertise and predictions.
Anatomically modern Homo sapiens (us), are thought to have emerged as a distinct species around 200,000 years ago in Africa. While we often imagine one species of hominid handing the baton to the next in a neat, linear “evolution of man” progression, Homo sapiens lived simultaneously with several other hominid species—Homo neanderthalensis, Homo floresiensis, and the much older Homo erectus, whose geographic and temporal boundaries remain fuzzy. They also had sex with each other, as evidenced by the amount of Neanderthal DNA in our genetic material (about 2.5% – 3% on average).
In recent decades, Susan Oyama and her colleagues in the burgeoning field of developmental systems theory have rejected the determinism inherent in the nature/nurture debate, arguing that behavior cannot be reduced to distinct biological or environmental causes. In Evolution’s Eye Oyama elaborates on her pioneering work on developmental systems by spelling out that work’s implications for the fields of evolutionary theory, developmental and social psychology, feminism, and epistemology. Her approach profoundly alters our understanding of the biological processes of development and evolution and the interrelationships between them. While acknowledging that, in an uncertain world, it is easy to “blame it on the genes,” Oyama claims that the renewed trend toward genetic determinism colors the way we think about everything from human evolution to sexual orientation and personal responsibility. She presents instead a view that focuses on how a wide variety of developmental factors interact in the multileveled developmental systems that give rise to organisms. Shifting attention away from genes and the environment as causes for behavior, she convincingly shows the benefits that come from thinking about life processes in terms of developmental systems that produce, sustain, and change living beings over both developmental and evolutionary time. Providing a genuine alternative to genetic and environmental determinism, as well as to unsuccessful compromises with which others have tried to replace them, Evolution’s Eye will fascinate students and scholars who work in the fields of evolution, psychology, human biology, and philosophy of science. Feminists and others who seek a more complex view of human nature will find her work especially congenial.
I’ve been thinking a lot about the concept of whether or not human evolution is a story of brains over brawn. I study the evolution of the human body and how and why the human body is the way it is, and I’ve worked a lot on both ends of the body. I’m very interested in feet and barefoot running and how our feet function, but I’ve also written and thought a lot about how and why our heads are the way they are. The more I study feet and heads, the more I realize that what’s in the middle also matters, and that we have this very strange idea —it goes back to mythology—that human evolution is primarily a story about brains, about intelligence, about technology triumphing over brawn.
Read also: The Evolution of the Human Head
There is no question that our large brains have provided humans an extraordinary advantage in the world. Still, the human brain is an incredibly expensive organ, taking up only about 2 percent of the body’s mass yet using more than a fifth of the body’s energy, and until about 2 million years ago none of our ancestors had a brain larger than an ape’s when compared to body size. So what kicked off the push for a larger brain? One possibility is that increased smarts helped our ancestors make better tools. Another is that larger brains helped us interact better with each other. Perhaps radical changes in the environment also demanded that our ancestors deal with a shifting world.
Our ability to think is one of our most puzzling characteristics. What would it be like to be unable to think? What would it be like to lack self-awareness? The complexity of this activity is striking. Thinking involves the interaction of a range of mental processes — attention, emotion, memory, planning, self-consciousness, free will, and language. So where did these processes arise? What evolutionary advantages were bestowed upon those with an ability to deceive, to plan, to empathize, or to understand the intentions of others? In this compelling work, the author embarks on an evolutionary detective story to try and solve one of the big mysteries surrounding human existence — how has the modern human being’s way of thinking come into existence? He starts by taking in turn the more basic cognitive processes, such as attention and memory, then builds upon these to explore more complex behaviours, such as self-consciousness, mind reading, and imitation. Having done this, he examines the consequences of ‘putting thought into the world’, using external media like cave paintings, drawings and writing.
My aim in this book is to describe how uniquely human thinking has emerged. I view knowledge as biologically grounded and I will start from the theory of evolution. However, as I shall argue, the biological foundation does not conflict with a humanistic outlook. On the contrary, I want to show that much of a humanistic worldview can be derived from an evolutionary story of our origins. I have dual objectives for the book. On the one hand, I want to present my own theory of the evolution of thinking. The theory is a synthesis of material from several scientific disciplines. On the other, I want to tell a story about how the cognitive capacities of Homo sapiens were shaped in a way that is accessible to a general audience.
Darwin’s theory of evolution by natural selection provided a scientific answer to a philosophical question: must design imply a designer? To the dismay and disbelief of many of Darwin’s contemporaries, and a great many still, his theory can answer the question in the negative. But there are many more questions yet to ask about seemingly designed systems, such as those posed by Alan Turing and John Searle: might such organized systems, natural and manmade, themselves be intelligent? The history of these inquiries among philosophers, scientists, and writers is the subject of Prof. James Paradis’ MIT course, “Darwin and Design.” The class explores such a diverse range of texts as Aristotle’s Physics, the Bible, Adam’s Smith’s Wealth of Nations, William Gibson’s Neuromancer, and of course, Darwin’s Origin of Species. Alongside the scientific conclusions so-called “Darwinism” draws are the implications for human self-understanding. Given the thousands of years in which humanity placed itself at the center of the universe, and the few hundred in which it at least held fast to concepts of its special creation, what, asks Prof. Paradis, does Darwinism mean “for ideas of nature and of mankind’s place therein?”
While most of us live our lives according to the working week, we did not evolve to be bound by industrial schedules, nor did the food we eat. Despite this, we eat the products of industrialization and often suffer as a consequence. This book considers aspects of changing human nutrition from evolutionary and social perspectives. It considers what a ‘natural’ human diet might be, how it has been shaped across evolutionary time and how we have adapted to changing food availability. The transition from hunter-gatherer and the rise of agriculture through to the industrialisation and globalisation of diet are explored. Far from being adapted to a ‘Stone Age‘ diet, humans can consume a vast range of foodstuffs. However, being able to eat anything does not mean that we should eat everything, and therefore engagement with the evolutionary underpinnings of diet and factors influencing it are key to better public health practice.