Archive for the ‘Humans’ Category
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.
The purpose of the present study was to determine the efficacy of investigating spatial cognitive abilities across two primate species using virtual reality. In this study, we presented four captive adult chimpanzees and 16 humans (12 children and 4 adults) with simulated environments of increasing complexity and size to compare species’ attention to visuo‐spatial features during navigation. The specific task required participants to attend to landmarks in navigating along routes in order to localize the goal site. Both species were found to discriminate effectively between positive and negative landmarks. Assessing path efficiency revealed that both species and all age groups used relatively efficient, distance reducing routes during navigation. Compared to the chimpanzees and adult humans however, younger children’s performance decreased as maze complexity and size increased. Surprisingly, in the most complex maze category the humans’ performance was less accurate compared to one female chimpanzee. These results suggest that the method of using virtual reality to test captive primates, and in particular, chimpanzees, affords significant cross‐species investigations of spatial cognitive and developmental comparisons.
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.
The evolution of human intelligence refers to a set of theories that attempt to explain how human intelligence has evolved. These theories are closely tied to the evolution of the human brain and to the emergence of human language.
The timeline of human evolution spans approximately 7 million years, from the separation of the Pan genus until the emergence of behavioral modernity by 50,000 years ago. The first 3 million years of this timeline concern Sahelanthropus, the following 2 million concern Australopithecus and the final 2 million span the history of actual human species (the Paleolithic).
Many traits of human intelligence, such as empathy, theory of mind, mourning, ritual, and the use of symbols and tools, are already apparent in great apes although in lesser sophistication than in humans.
Read also: Evolution of the brain and intelligence
Paleoanthropologists from the University of Zurich have uncovered the intact skull of an early Homo individual in Dmanisi, Georgia. This find is forcing a change in perspective in the field of paleoanthropology: human species diversity two million years ago was much smaller than presumed thus far. However, diversity within the “Homo erectus,” the first global species of human, was as great as in humans today.
This shows the need for a change in perspective: the African fossils from around 1.8 million years ago likely represent representatives from one and the same species, best described as “Homo erectus.” This would suggest that “Homo erectus” evolved about 2 million years ago in Africa, and soon expanded through Eurasia — via places such as Dmanisi — as far as China and Java, where it is first documented from about 1.2 million years ago. Comparing diversity patterns in Africa, Eurasia and East Asia provides clues on the population biology of this first global human species.
This makes Homo erectus the first “global player” in human evolution.
You are a walking ecosystem. And you are not alone. Ever. Microbial life teems on, and in, your body. If you’re healthy, these life forms live in harmony with you in a stable and balanced system, where host and guest alike contribute to the rhythm and hum of a cooperative community.
Humans and microbes have coevolved to a point of mutual benefit—we need each other. The number of microbial cells in our bodies outstrip the number of human cells by about ten to one. And while the human genome contains approximately 30,000 genes, the microbial genome, the microbiome, is made up of more than four million genes. We are more “them” than “us.”
There’s a growing interest in studying the ecosystem that is the human microbiome, and it’s more than a research trend. It may herald a shift in how we think about human health and medicine and our place in the natural world.