Complexity in artificial life

Master'sMASTER OF SCIENC

The role of play objects and object play in human cognitive evolution and innovation

Abstract: In this contribution, we address a major puzzle in the evolution of human material culture: If maturing individuals just learn their parental generation’s material culture, then what is the origin of key innovations as documented in the archeological record? We approach this question by coupling a life-history model of the costs and benefits of experimentation with a niche-construction perspective. Niche-construction theory suggests that the behavior of organisms and their modification of the world around them have important evolutionary ramifications by altering developmental settings and selection pressures. Part of Homo sapiens’ niche is the active provisioning of children with play objects — sometimes functional miniatures of adult tools — and the encouragement of object play, such as playful knapping with stones. Our model suggests that salient material culture innovation may occur or be primed in a late childhood or adolescence sweet spot when cognitive and physical abilities are sufficiently mature but before the full onset of the concerns and costs associated with reproduction. We evaluate the model against a series of archeological cases and make suggestions for future research

ApoB100-LDL Acts as a Metabolic Signal from Liver to Peripheral Fat Causing Inhibition of Lipolysis in Adipocytes

International audienceBACKGROUND: Free fatty acids released from adipose tissue affect the synthesis of apolipoprotein B-containing lipoproteins and glucose metabolism in the liver. Whether there also exists a reciprocal metabolic arm affecting energy metabolism in white adipose tissue is unknown. METHODS AND FINDINGS: We investigated the effects of apoB-containing lipoproteins on catecholamine-induced lipolysis in adipocytes from subcutaneous fat cells of obese but otherwise healthy men, fat pads from mice with plasma lipoproteins containing high or intermediate levels of apoB100 or no apoB100, primary cultured adipocytes, and 3T3-L1 cells. In subcutaneous fat cells, the rate of lipolysis was inversely related to plasma apoB levels. In human primary adipocytes, LDL inhibited lipolysis in a concentration-dependent fashion. In contrast, VLDL had no effect. Lipolysis was increased in fat pads from mice lacking plasma apoB100, reduced in apoB100-only mice, and intermediate in wild-type mice. Mice lacking apoB100 also had higher oxygen consumption and lipid oxidation. In 3T3-L1 cells, apoB100-containing lipoproteins inhibited lipolysis in a dose-dependent fashion, but lipoproteins containing apoB48 had no effect. ApoB100-LDL mediated inhibition of lipolysis was abolished in fat pads of mice deficient in the LDL receptor (Ldlr(-/-)Apob(100/100)). CONCLUSIONS: Our results show that the binding of apoB100-LDL to adipocytes via the LDL receptor inhibits intracellular noradrenaline-induced lipolysis in adipocytes. Thus, apoB100-LDL is a novel signaling molecule from the liver to peripheral fat deposits that may be an important link between atherogenic dyslipidemias and facets of the metabolic syndrome

The archaeology of teaching and the evolution of Homo docens

CITATION: Gärdenfors, P. & Högberg, A. 2017. The Archaeology of Teaching and the Evolution of Homo docens. Current Anthropology, 58(2):188-208. doi:10.1086/691178.The original publication is available at https://www.journals.uchicago.edu/openTeaching is present in all human societies, while within other species it is very limited. Something happened during the evolution of Homo sapiens that also made us Homo docens—the teaching animal. Based on discussions of animal and hominin learning, we analyze the evolution of intentional teaching by a series of levels that require increasing capacities of mind reading and communication on the part of the teacher and the learner. The levels of teaching are (1) intentional evaluative feedback, (2) drawing attention, (3) demonstrating, (4) communicating concepts, and (5) explaining relations between concepts. We suggest that level after level has been added during the evolution of teaching.We demonstrate how different technologies depend on increasing sophistication in the levels of cognition and communication required for teaching them. As regards the archaeological evidence for the different levels, we argue that stable transmission of the Oldowan technology requires at least teaching by demonstration and that learning the late Acheulean hand-axe technology requires at least communicating concepts. We conclude that H. docens preceded H. sapiens.Publisher's versio

How do Swedish paediatric clinics diagnose coeliac disease? Results of a nationwide questionnaire study

Background and aim: Diagnosis of coeliac disease is based on the demonstration of enteropathy in a small bowel biopsy. Correct diagnosis is of utmost importance, since the need for dietary management is life long, and inadequate treatment may lead to potentially serious complications. The Swedish Working Group for Paediatric Coeliac Disease has published guidelines for the diagnosis of childhood coeliac disease. The present questionnaire was designed in order to create the basis for revision of those guidelines. Methods: In 2004, a nationwide questionnaire concerning current diagnostic routines was sent to all 45 paediatric clinics performing small bowel biopsy. All clinics responded. Results: All clinics base their diagnosis on small bowel biopsy findings at presentation. Furthermore, in 24 (53%) of the clinics, children with suspected coeliac disease are investigated by small bowel biopsy both at presentation and follow-up while on a gluten-free diet. Eighteen (40%) of the clinics employ a different diagnostic routine for children under 2 y of age than for those older than 2 y. All clinics use coeliac serological testing at various stages of the diagnostic procedure. Conclusion: All Swedish paediatric clinics perform a small bowel biopsy at presentation in children with suspected coeliac disease, and the majority of clinics perform a second biopsy when the child is on a gluten-free diet. Serological testing is frequently used as a diagnostic aid and in the monitoring of the disease while on a gluten-free diet