244 research outputs found
The Cheating Cell: How Evolution Helps Us Understand and Treat Cancer/ Athena Aktipis.
No full textIn English.Includes bibliographical references and index.A fundamental and groundbreaking reassessment of how we view and manage cancer When we think of the forces driving cancer, we don't necessarily think of evolution. But evolution and cancer are closely linked, for the historical processes that created life also created cancer. The Cheating Cell delves into this extraordinary relationship, and shows that by understanding cancer's evolutionary origins, researchers can come up with more effective, revolutionary treatments. Athena Aktipis goes back billions of years to explore when unicellular forms became multicellular organisms. Within these bodies of cooperating cells, cheating ones arose, overusing resources and replicating out of control, giving rise to cancer. Aktipis illustrates how evolution has paved the way for cancer's ubiquity, and why it will exist as long as multicellular life does. Even so, she argues, this doesn't mean we should give up on treating cancer-in fact evolutionary approaches offer new and promising options for the disease's prevention and treatments that aim at long-term management rather than simple eradication. Looking across species-from sponges and cacti to dogs and elephants-we are discovering new mechanisms of tumor suppression and the many ways that multicellular life-forms have evolved to keep cancer under control. By accepting that cancer is a part of our biological past, present, and future-and that we cannot win a war against evolution-treatments can become smarter, more strategic, and more humane. Unifying the latest research from biology, ecology, medicine, and social science, The Cheating Cell challenges us to rethink cancer's fundamental nature and our relationship to it.Frontmatter -- CONTENTS -- Acknowledgments -- 1. Introduction: Evolution in the Flesh -- 2. Why Does Cancer Evolve? -- 3. Cheating in Multicellular Cooperation -- 4. Cancer from Womb to Tomb -- 5. Cancer across the Tree of Life -- 6. The Hidden World of Cancer Cells -- 7. How to Control Cancer -- Notes -- Bibliography -- Index1 online resource (256 pages)
Parental investment without kin recognition: simple conditional rules for parent–offspring behavior
No full textSpecies differ widely with regard to parental investment strategies and mechanisms underlying those strategies. The passing of benefits to likely genetic offspring can be mediated through a number of different computational and behavioral systems. We report results from an agent-based model in which offspring maintain proximity with parents and parents transmit benefits to offspring without the capacity of either parent or offspring to “recognize” one another. Instead, parents follow a simple rule to emit benefits after reproducing and offspring follow a simple rule of moving in the direction of positive benefit gradients. This model differs from previous models of spatial kin-based altruism in that individuals are modeled as having different behavioral rules at different life stages and benefits are transmitted unidirectionally from parents to offspring. High rates of correctly directed parental investment occur when mobility and sociality are low and parental investment occurs over a short period of time. We suggest that strategies based on recognition and bonding/attachment might serve to increase rates of correctly directed parental investment under parameters that are shown here to otherwise lead to high rates of misdirected and wasted parental investment.Fil: Aktipis, C. Athena. University of Arizona; Estados UnidosFil: Fernandez Duque, Eduardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Centro de Ecología Aplicada del Litoral. Universidad Nacional del Nordeste. Centro de Ecología Aplicada del Litoral; Argentina. University of Pennsylvania; Estados Unido
Tethya wilhelma (Porifera) Is Highly Resistant to Radiation Exposure and Possibly Cancer
No full textThere are no reports of cancer in sponges, despite them having somatic cell turnover, long lifespans, and no specialized adaptive immune cells. In order to investigate whether sponges are cancer resistant, we exposed a species of sponge, Tethya wilhelma, to X-rays. We found that T. wilhelma can withstand 518 Gy of X-ray radiation. That is approximately 100 times the lethal dose for humans. A single high dose of X-rays did not induce cancer in T. wilhelma, providing the first experimental evidence of cancer resistance in the phylum Porifera. Following X-ray exposure, we found an overexpression of genes involved in DNA repair, signaling transduction pathways, and epithelial-to-mesenchymal transition. T. wilhelma has the highest level of radiation resistance that has yet been observed in animals that have sustained somatic cell turnover. This may make them an excellent model system for studying cancer resistance and developing new approaches for cancer prevention and treatment
Risk pooling norms as a Stag Hunt Game.
No full textIn a computer simulation (Aktipis et al. 2016), need-based vs. debt-based strategies correspond to a Stag Hunt Game, with need-based transfers being dominant to debt-based transfers. Payoffs in this game theoretic matrix are given in percent of agents surviving at 50 years. Both players get the highest payoff if they both choose need-based transfers.</p
Cancer across the tree of life: cooperation and cheating in multicellularity
No full textMulticellularity is characterized by cooperation among cells for the development, maintenance and reproduction of the multicellular organism. Cancer can be viewed as cheating within this cooperative multicellular system. Complex multicellularity, and the cooperation underlying it, has evolved independently multiple times. We review the existing literature on cancer and cancer-like phenomena across life, not only focusing on complex multicellularity but also reviewing cancer-like phenomena across the tree of life more broadly. We find that cancer is characterized by a breakdown of the central features of cooperation that characterize multicellularity, including cheating in proliferation inhibition, cell death, division of labour, resource allocation and extracellular environment maintenance (which we term the five foundations of multicellularity). Cheating on division of labour, exhibited by a lack of differentiation and disorganized cell masses, has been observed in all forms of multicellularity. This suggests that deregulation of differentiation is a fundamental and universal aspect of carcinogenesis that may be underappreciated in cancer biology. Understanding cancer as a breakdown of multicellular cooperation provides novel insights into cancer hallmarks and suggests a set of assays and biomarkers that can be applied across species and characterize the fundamental requirements for generating a cancer
Principles of cooperation across systems: from human sharing to multicellularity and cancer
No full textWhen to walk away and when to stay: Cooperation evolves when agents can leave uncooperative partners and groups
No full textCooperation among group members, coworkers and community members can provide benefits for all involved parties. However, groups of all kinds are plagued by free riders, or individuals who take advantage of cooperative group members by benefiting from being a part of the group without contributing, resulting in a social dilemma or \u27tragedy of the commons.\u27 This phenomenon is not unique to humans; free riders can be identified in organisms as simple as bacteria. This has lead to the puzzling question of how cooperation is maintained in social groups of humans and other animals, given higher payoffs for free riding than for cooperation. In order to address this question, I simulate individuals who use a simple Walk Away rule to leave uncooperative partners or groups, and show that cooperation is favored under a variety of parameter values when agents can use this rule. When agents use the Walk Away rule, more cooperative partnerships and groups are more stable than less cooperative ones. This promotes assortment, or the preferential interaction of cooperators with one another, which favors the evolution of cooperation. It is shown that in dyadic partnerships Walk Away can outperform the well-known Tit-for-Tat strategy. In group-wise interactions, the Walk Away rule generates large number of relatively small groups and differential group stability based on average cooperativeness. These features maintain selection for cooperation by generating population structures that promote group selection. The simple Walk Away rule does not require complex individual level abilities such as long-term memory, recognition of group members or punishment, suggesting that complex cognitive abilities are not necessary for cooperation to be promoted
Sacredness as an implied threat of supernatural punishment: the case of need-based transfers
No full textIs cooperation viable in mobile organisms? Simple Walk Away rule favors the evolution of cooperation in groups
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