Peter Hammerstein

Peter Hammerstein
Humboldt-Universität zu Berlin | HU Berlin · Berlin School of Mind and Brain

About

150
Publications
17,430
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9,329
Citations
Citations since 2017
29 Research Items
3322 Citations
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20172018201920202021202220230100200300400500600
20172018201920202021202220230100200300400500600

Publications

Publications (150)
Article
Full-text available
Most analyses of the origins of cultural evolution focus on when and where social learning prevails over individual learning, overlooking the fact that there are other developmental inputs that influence phenotypic fit to the selective environment. This raises the question of how the presence of other cue ‘channels’ affects the scope for social lea...
Article
Full-text available
Cultural evolution theory has long been inspired by evolutionary biology. Conceptual analogies between biological and cultural evolution have led to the adoption of a range of formal theoretical approaches from population dynamics and genetics. However, this has resulted in a research programme with a strong focus on cultural transmission. Here, we...
Article
Full-text available
The social structure of animal groups is considered to have an impact on their health and welfare. This could also be true for animals under commercial conditions, but research in this area has been limited. Pigs for example are known to be very social animals, but information about their grouping behavior is mostly derived from wild boars and a li...
Article
Full-text available
Most analyses of the origins of cultural evolution focus on when and where social learning prevails over individual learning, overlooking the fact that there are other developmental inputs that influence phenotypic fit to the selective environment. This raises the question how the presence of other cue 'channels' affects the scope for social learni...
Preprint
Full-text available
Cultural evolution theory has long been inspired by evolutionary biology. Conceptual analogies between biological and cultural evolution have led to the adoption of a range of formal theoretical approaches from population dynamics and genetics. However, this has resulted in a research programme with a strong focus on cultural transmission. Here, we...
Article
Full-text available
Collective action of resource users is essential for sustainability. Yet, often user groups are socioculturally heterogeneous, which requires cooperation to be established across salient group boundaries. We explore the effect of this type of heterogeneity on resource extraction in lab-in-the-field Common Pool Resource (CPR) experiments in Zanzibar...
Data
Plot of payoff function. (PNG)
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Details on procedure, instructions and materials. (DOCX)
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Original survey questions. (DOCX)
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Payoff function in the CPR experiment. (DOCX)
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Mixed-effect ordered logit specification of regressions. (DOCX)
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Self-reported strategic goals. (DOCX)
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Principal Component Analysis for wealth. (DOCX)
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Additional Tobit panel regressions. (DOCX)
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Discussion of unbalanced sample. (DOCX)
Article
Full-text available
Genetic polymorphism can contribute to local adaptation in heterogeneous habitats, for instance, as a single locus with alleles adapted to different habitats. Phenotypic plasticity can also contribute to trait variation across habitats, through developmental responses to habitat-specific cues. We show that the genetic architecture of genetically po...
Article
Full-text available
There can be genetic conflict between genome elements differing in transmission patterns, and thus in evolutionary interests. We show here that the concept of genetic conflict provides new insight into local adaptation and phenotypic plasticity. Local adaptation to heterogeneous habitats sometimes occurs as tightly linked clusters of genes with amo...
Article
Full-text available
Maternally inherited symbionts such as Wolbachia have long been seen mainly as reproductive parasites, with deleterious effects on host fitness. It is becoming clear, however, that, frequently, these symbionts also have beneficial effects on host fitness, either along with reproductive parasitism or not. Using the examples of cytoplasmic incompatib...
Article
Full-text available
When allopatric species with incomplete prezygotic isolation come into secondary contact, the outcome of their interaction is not easily predicted. The parasitoid wasp Encarsia suzannae (iES), infected by Cardinium inducing cytoplasmic incompatibility (CI), and its sibling species E. gennaroi (EG), not infected by bacterial endosymbionts, may have...
Data
Female choice mating test: one infected Encarsia suzannae female paired with one conspecific male and one male of Encarsia gennaroi. The E. suzannae female mates with the conspecific male.
Data
Multiple choice mating test: two pairs of infected E. suzannae and two pairs of E. gennaroi are used. Males (on the right) and females (on the left) are kept separate, then the barrier is removed to allow mating. Two matings can be observed: first, a mating between an E. suzannae female and an E. gennaroi male, then an intraspecific E. gennaroi mat...
Data
Female choice mating test: one Encarsia gennaroi female paired with one conspecific male and one male of a cured strain of Encarsia suzannae. The E. gennaroi female mates with the cospecific male
Data
Female choice mating test: one cured Encarsia suzannae female paired with one conspecific male and one male of Encarsia gennaroi. The E. suzannae female mates with the heterospecific male.
Article
Full-text available
There are many inputs during development that influence an organism's fit to current or upcom-ing environments. These include genetic effects, transgenerational epigenetic influences, environmental cues and developmental noise, which are rarely investigated in the same formal framework. We study an analytically tractable evolutionary model, in whic...
Article
Full-text available
The potential importance of cytoplasmic incompatibility (CI) – inducing bacterial symbionts in speciation of their arthropod hosts has been debated. Theoretical advances have led to a consensus that a role is plausible when CI is combined with other isolating barriers. However, the insect model systems Nasonia and Drosophila are the only two experi...
Article
Full-text available
There are many situations where relatives interact while at the same time there is genetic polymorphism in traits influencing survival and reproduction. Examples include cheater-cooperator polymorphism and polymorphic microbial pathogens. Environmental heterogeneity, favoring different traits in nearby habitats, with dispersal between them, is one...
Data
Details of model description, results and individual-based simulations. (PDF)
Article
Full-text available
Cooperation between organisms can often be understood, like trade between merchants, as a mutually beneficial exchange of services, resources or other ‘commodities’. Mutual benefits alone, however, are not sufficient to explain the evolution of trade-based cooperation. First, organisms may reject a particular trade if another partner offers a bette...
Article
This chapter reviews the origin and development of game-theoretic ideas in biology. It covers more than half a century of research and focuses on those models and conceptual advancements that are rooted in fundamental biological theory and have been exposed to substantial empirical scrutiny. The different areas of research-ranging from molecules an...
Article
Full-text available
Wolbachia are intracellular bacteria that infect a vast range of arthropod species, making them one of the most prevalent endosymbionts in the world. Wolbachia's stunning evolutionary success is mostly due to their reproductive parasitism but also to mutualistic effects such as increased host fecundity or protection against pathogens. However, the...
Article
Full-text available
We use an evolutionary model to simulate agents who choose between two options with stochastically varying payoffs. Two types of agents are considered: individual learners, who rely on trial-and-error methods, and social learners, who imitate the wealthiest sampled individual. Agents adapt to changing environments within one generation by using the...
Article
Full-text available
Genetic incompatibilities are supposed to play an important role in speciation. A general (theoretical) problem is to explain the persistence of genetic diversity after secondary contact. Previous theoretical work has pointed out that Dobzhansky-Muller incompatibilities (DMI) are not stable in the face of migration unless local selection acts on th...
Article
Full-text available
Wolbachia are the most abundant bacterial endosymbionts among arthropods. Although maternally inherited, they do not conform to the widespread view that vertical transmission inevitably selects for beneficial symbionts. Instead, Wolbachia are notorious for their reproductive parasitism which, although lowering host fitness, ensures their spread. Ho...
Article
Full-text available
Biological market theory has been used successfully to explain cooperative behavior in many animal species. Microbes also engage in cooperative behaviors, both with hosts and other microbes, that can be described in economic terms. However, a market approach is not traditionally used to analyze these interactions. Here, we extend the biological mar...
Article
Full-text available
Parent-offspring conflict (POC) describes the evolutionary conflict between offspring and their parents over parental resource allocation. Offspring are expected to demand more resources than their parents are willing to supply because these offspring are more related to their own than to their siblings' offspring. Kin selection acts to limit these...
Article
Wolbachia are bacterial endosymbionts that manipulate the reproduction of their arthropod hosts. Although theory suggests that infections are frequently lost within host species due to the evolution of resistance, Wolbachia infect a huge number of species worldwide. This apparent paradox suggests that horizontal transmission between host species ha...
Chapter
Full-text available
The study of games and decisions has long been guided by a philosophical discourse on concepts of rationality and their implications. This discourse has led to a large body of mathematical work and kept generations of researchers busy, but few serious attempts have been made to understand decision making in the real world. Over the last decades, ho...
Article
Full-text available
Wolbachia are intracellular bacteria that manipulate the reproduction of their arthropod hosts in remarkable ways. They are predominantly transmitted vertically from mother to offspring but also occasionally horizontally between species. In doing so, they infect a huge range of arthropod species worldwide. Recently, a statistical analysis estimated...
Chapter
Full-text available
Game theory provides a useful framework for conceptualizing social decisions in which one person's behavior affects outcomes that matter to other individuals. Game theory can also help us understand the computational problems inherent in social decision making. To explain human adaptive success, culture plays an important role. Models from populati...
Article
Conventional decision theory is normative and it attempts to identify decisions that are in some sense optimal. The decision maker is often assumed to have all the mental capabilities that real human beings can only dream of. Classical game theory has built on this approach and many of its scholars have almost routinely referred to the normative ch...
Data
Text S1 explains in more detail the formalism of the general framework used to study the goalkeeper-model, the lock-key-model, and the mistiming-model. Additional predictions derived from the models are presented, as well as proofs for all statements. Moreover, the tentative tests on CI levels are explained in more detail. (PDF)
Article
Full-text available
Wolbachia are intracellular bacteria transmitted almost exclusively vertically through eggs. In response to this mode of transmission, Wolbachia strategically manipulate their insect hosts' reproduction. In the most common manipulation type, cytoplasmic incompatibility, infected males can only mate with infected females, but infected females can ma...
Data
AvCystatin stimulated signaling pathways are partially connected but are independently addressed by AvCystatin. Thioglycollate elicited peritoneal macrophages from BALB/c mice were treated with 0.5 µM AvCystatin in the presence of LY294002 (5 µM, PI3K inhibitor), SB203580 (0.5 µM, p38 inhibitor) or U0129 (5 µM, Mek1/2 inhibitor). Cells were pre-inc...
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Wiring scheme of the master model of IL-10 production and regulation in macrophages after AvCystatin stimulation. This graphical model represents possible IL-10 regulation mechanisms (regulation of IL-10 through DUSP, IL-10 or an independent molecule (IM)) and comprises the possible mechanism of achieving this regulation. Wiring scheme was performe...
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Work flow describing the process of model selection. 35 alternative models are generated based on literature and experimental data, fitted to the available experimental data (ERK, p38, and IL-10) and ranked based on the AIC. The best model is selected and checked if it predicts the experimental data. If not, the next best model is selected until ha...
Data
Mapping the experimental data from DUSP 1 and DUSP2 with predicted DUSP. The DUSP values of DUSP 1 and DUSP2 from Fig. 8A were converted to arbitrary units and overlay with predicted DUSP from model 15. (0.32 MB TIF)
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Mathematical models derived from the master model shown in figure S2. IM: independent molecule, KI: kinase inhibition, PA: phosphatase activation, →: activation, ┤: repression. (0.05 MB DOC)
Article
Full-text available
Parasitic worms alter their host's immune system to diminish the inflammatory responses directed against them, using very efficient immunomodulating molecules. We have previously shown that the helminth immunomodulator cystatin (AvCystatin) profoundly reduces the progression of inflammatory diseases via modulation of macrophages. Here we elucidate...
Article
Rarely do human behavioral scientists and scholars study language, music, and other forms of communication as strategies---a means to some end. Some even deny that communication is the primary function of these phenomena. Here we draw upon selections of our earlier work to briefly define the strategy concept and sketch how decision theory, develope...
Article
Studies of the evolution of helping have traditionally used the explanatory frameworks of reciprocity and altruism towards relatives, but recently there has been an increasing interest in other kinds of explanations. We review the success or otherwise of work investigating alternative processes and mechanisms, most of which fall under the heading o...
Article
Group defence of territories is found in many gregarious mammalian carnivores, including lions, canids, and hyenas. In these taxa, group members often mark territory boundaries and direct aggressive behaviour towards alien conspecifics found within the territory (Boydston et al., 2001). Middle Pleistocene hominids such as Neanderthals occupied an e...
Article
Male-killing (MK) bacteria are vertically transmitted endosymbionts that selectively kill the male offspring of their hosts. Simple mathematical models describe the infection dynamics using two parameters, the bacterial transmission rate and a fitness compensation for siblings of killed males. These models cannot explain two phenomena that have bee...
Article
Parasitic nematodes can downregulate the immune response of their hosts through the induction of immunoregulatory cytokines such as interleukin-10 (IL-10). To define the underlying mechanisms, we measured in vitro the production of IL-10 in macrophages in response to cystatin from Acanthocheilonema viteae, an immunomodulatory protein of filarial ne...
Article
Current neurobiological theory of drug use is based on the observation that all addictive drugs induce changes in activity of dopaminergic circuitry, interfering with reward processing, and thus enhancing drug seeking and consumption behaviors. Current theory of drug origins, in contrast, views almost all major drugs of abuse, including nicotine, c...
Data
Appendix S1 contains mathematical formulae and derivations as well as additional figures. (0.45 MB DOC)
Article
Full-text available
Wolbachia are intracellular bacteria widely distributed among arthropods and nematodes. In many insect species these bacteria induce a cytoplasmic incompatibility (CI) between sperm of infected males and eggs of uninfected females. From an evolutionary point of view, CI is puzzling: In order to induce this modification-rescue system, Wolbachia affe...
Article
Genetic influx into a population often does not correspond to the real migration rate (m) of individuals, due to class structure within the population. The effective migration rate (m(e)) is a concept to measure gene flow in such a situation. The ratio of the effective migration rate to the real migration rate (m(e)/m) is called the gene flow facto...
Article
Full-text available
Neurobiological models of drug abuse propose that drug use is initiated and maintained by rewarding feedback mechanisms. However, the most commonly used drugs are plant neurotoxins that evolved to punish, not reward, consumption by animal herbivores. Reward models therefore implicitly assume an evolutionary mismatch between recent drug-profligate e...
Article
Full-text available
Just as many aspects of individual decisions are sometimes called "unconscious" or "automatic," we know that some institutions have evolved through "unconscious," nondeliberative mechanisms. Their function can also be largely nondeliberative, as in the case of some institutions that may structure behavior without requiring any reflection on the par...
Article
Full-text available
A long-standing theoretical tradition in clinical psychology and psychiatry sees deliberate self-harm (DSH), such as wrist-cutting, as functionala means to avoid painful emotions, for example, or to elicit attention from others. There is substantial evidence that DSH serves these functions. Yet the specific links between self-harm and such function...
Article
Wolbachia are intracellular bacteria found in many species of arthropods and nematodes. They manipulate the reproduction of their arthropod hosts in various ways, may play a role in host speciation and have potential applications in biological pest control. Estimates suggest that at least 20% of all insect species are infected with Wolbachia. These...
Data
Full-text available
Table 1 Relationships between plant neurotoxins commonly used as drugs and CNS receptors. Table 2 Human cytochrome P450 natural substrates and enzyme kinetics constants. Table 3 Example ethnic population frequencies of CYP2A6 and CYP2D6 alleles with known in vivo enzyme activity. References
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Incomplete transmission. (0.03 MB DOC)
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Equilibrium Frequencies of infected T1 Individuals (0.03 MB DOC)
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Model description. (0.05 MB DOC)
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Lower estimation of the critical migration rate. (0.04 MB DOC)
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Formula for the effective migration rate. (0.02 MB DOC)
Article
Multiple infection of individual hosts with several species or strains of maternally inherited endosymbionts is commonly observed in animals, especially insects. Here, we address theoretically the effect of co-infection on the optimal density of the endosymbionts in doubly infected hosts. Our analysis is based on the observation that a maternally i...
Article
Wolbachia are intracellular, maternally inherited bacteria that are widespread among arthropods and commonly induce a reproductive incompatibility between infected male and uninfected female hosts known as unidirectional cytoplasmic incompatibility (CI). If infected and uninfected populations occur parapatrically, CI acts as a post-zygotic isolatio...
Article
Full-text available
Bacteria of the genus Wolbachia are among the most common endosymbionts in the world. In many insect species these bacteria induce a sperm-egg incompatibility between the gametes of infected males and uninfected females, commonly called unidirectional cytoplasmic incompatibility (CI). It is generally believed that unidirectional CI cannot promote s...
Article
There is of course a fair amount of understanding of the many instances where organisms possess traits that appear designed for providing benefits to others, and where these organisms are relatively independent and interactions are repeated or extend over time. That kind of traits and behaviours are most prevalent in interspecific interactions and...
Article
Asymmetric gene flow is generally believed to oppose natural selection and potentially impede adaptation. Whilst the cause of asymmetric gene flow has been seen largely in terms of variation in population density over space, asymmetric gene flow can also result from varying sex ratios across subpopulations with similar population sizes. We model th...
Article
Economists and psychologists have been testing Nash equilibrium predictions of game theory models of human behavior. In many instances, humans do not conform to the predictions. These results are of great interest to biologists because they also raise questions about well-known ESS models of cooperation. Cooperation in certain one-shot, anonymous i...
Article
Genes in Conflict. The Biology of Selfish Genetic Elements. By Austin Burt and Robert Trivers. Harvard University Press, Cambridge, MA, 2006. 620 pp. $35, £21.95. ISBN 0-674-01713-7. The authors explore molecular, genetic, behavioral, and evolutionary aspects of selfish genetic elements--DNA that acts to advance its own replication at the expense...
Article
Full-text available