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Dinos in the Dark
 The scleral ring highlighted in a pterosaur fossil. Dr. Lars Schmitz
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It has been traditionally thought that dinosaurs and reptiles from the Mesozoic Era were diurnal - they were active only during the day. The thinking was that being active at night was too great an energy cost, plus they didn't have the capacity to see when light was limited. But new research by
Dr. Lars Schmitz from the Department of Evolution and Ecology at the University of California, Davis has found that some of these ancient reptiles were nocturnal. By studying the eye shape and structure of living mammals, reptiles and birds, he was able to identify the characteristics specific to those who are nocturnal. The key is the scleral ring, a leathery structure inside the eyeball that corresponds to eye shape. It helps facilitate visual activity at night. Because the scleral ring found in many of the 33 archosaur fossils he studied was similar to living nocturnal animals, it can be concluded that those with this specific eye structure were also nocturnal.
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Avian Olfactory Evolution
 The evolution of the olfactory bulb in birds, courtesy Ryan Ridgely and Lawrence Witmer, Ohio University.
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When birds evolved from small theropod dinosaurs, It was thought that their sense of smell declined, since their vision and balance improved as they took flight. But a new study by
Dr. Darla Zelenitsky, an Assistant Professor of Paleontology from the University of Calgary, has found that sense of smell actually improved along with the other characteristics we associate with many birds today. By studying the part of the brain involved in processing smell in modern birds and mammals, it was demonstrated that the bigger the 'olfactory bulb', the greater the sense of smell. CT scans were then used to determine the size of the olfactory bulb in dinosaur fossils. This enabled specific comparisons to modern birds to be made. For example,
Bambiraptor, a small
Velociraptor, had the same size olfactory bulb as modern turkey vultures and albatrosses - both known for their keen sense of smell. This supports the theory that not only did sense of smell improve as birds evolved, it may even have helped them survive the mass extinction 65 million years ago, which most of the dinosaurs did not.
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Recreating the Bamboo Age
 Chinese archeologist Yiyuan Li utilizes a replicated stone chopper to fell a thick bamboo stalk. (Photo: Metin I. Eren/SMU)
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Prehistoric humans achieved a lot with stone tools, and some cultures developed them to the acme of refinement. However, archeologists have been puzzled by the fact that in Southeast Asia, the stone tools they've found were universally simple and crude. Some have suggested that this was because early humans used flexible, plentiful bamboo instead, as their material for more sophisticated tools. Experimental archeologist
Metin Eren, a PhD at Southern Methodist University, had an opportunity to test this idea. Mr. Eren has spent years developing his skills as a flint-knapper - a maker of stone tools. He decided to try his hand at bamboo tool making. He rediscovered techniques that allowed him to make various bamboo implements, using a few simple rock edges to start the process. He had great success making spears, and breaking down bamboo for weaving. However, his attempts to make a bamboo knife - an essential tool for early humans - were disappointing: the knives could be made very sharp indeed, but weren't durable enough to be really useful.
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Wasps Airlift Ants
When species compete for food, often the fight can turn nasty and aggressive. But the yellow jacket wasp, an invasive species found in great abundance on the southern island of New Zealand, has learned a unique way of dealing with its competition - an acid spraying ant. The conflict is commonly over dead insects and other sources of protein on the forest floor. As the ants swarm the food, the much larger wasp approaches and very carefully picks up an individual ant in its mandibles. It then flies backwards with the ant and drops it from a height. The ant is left dazed, but not hurt. The distance the wasp flies, as well as the frequency of flights, increases with the size of the ant swarm.
Dr. Philip Lester from the School of Biological Sciences at Victoria University of Wellington in New Zealand, feels this is evidence that the wasp has learned to assess the degree of competition, and adjust its behaviour accordingly.
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The Anthropology of In-Laws
Dr. Kim Hill, an anthropologist and professor in the School of Human Evolution and Social Change at Arizona State University, has been studying hunter-gatherer societies for his entire career. One of the questions he's been interested in is: what aspects of these basic human cultural systems are different from those of apes, primates and other animals? Using his own data and that of other researchers, he thinks he now has at least part of the answer: In-laws. Human culture is unique because of the extended bonds that are forged between non-related individuals when their relatives mate. Because humans pair-bond, and both males and females care for their children, then uncles, aunts, grandparents and cousins on both sides of the family all recognize the common interest they have in raising those children. In other species, these relationships are often unrecognized, and so these extended networks don't form. Dr. Hill suspects that these networks allow greater cooperation and communication between human groups, and this could have facilitated the development of the sophisticated culture that typifies human societies.
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Theme music bed copyright Raphaël Gluckstein, Creative Commons License by-nc-nd-2.0
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Ache hunter gatherer, copyright Kim Hill
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