Chemical patterns of colony membership and mother-offspring similarity in Antarctic fur seals are reproducible

Replication studies are essential for evaluating the validity of previous research findings. However, it has proven challenging to reproduce the results of ecological and evolutionary studies, partly because of the complexity and lability of many of the phenomena being investigated, but also due to small sample sizes, low statistical power and publication bias. Additionally, replication is often considered too difficult in field settings where many factors are beyond the investigator’s control and where spatial and temporal dependencies may be strong. We investigated the feasibility of reproducing original research findings in the field of chemical ecology by performing an exact replication of a previous study of Antarctic fur seals (Arctocephalus gazella). In the original study, skin swabs from 41 mother-offspring pairs from two adjacent breeding colonies on Bird Island, South Georgia, were analyzed using gas chromatography-mass spectrometry. Seals from the two colonies differed significantly in their chemical fingerprints, suggesting that colony membership may be chemically encoded, and mothers were also chemically similar to their pups, hinting at the possible involvement of phenotype matching in mother-offspring recognition. In the current study, we generated and analyzed chemical data from a non-overlapping sample of 50 mother-offspring pairs from the same two colonies 5 years later. The original results were corroborated in both hypothesis testing and estimation contexts, with p-values remaining highly significant and effect sizes, standardized between studies by bootstrapping the chemical data over individuals, being of comparable magnitude. However, exact replication studies are only capable of showing whether a given effect can be replicated in a specific setting. We therefore investigated whether chemical signatures are colony-specific in general by expanding the geographic coverage of our study to include pups from a total of six colonies around Bird Island. We detected significant chemical differences in all but a handful of pairwise comparisons between colonies. This finding adds weight to our original conclusion that colony membership is chemically encoded, and suggests that chemical patterns of colony membership not only persist over time but can also be generalized over space. Our study systematically confirms and extends our previous findings, while also implying more broadly that spatial and temporal heterogeneity need not necessarily negate the reproduction and generalization of ecological research findings.

Epilogue

This epilogue provides a practical flowchart for interpreting the best practices for replication. Taking the specific actions shown in the flowchart will help researchers to bridge, albeit not completely and permanently close, the gaps inherent in replication. At each branch point, making the “wrong” decision—for example, ignoring (that is, not recording) or conflating (that is, not recording separately) the relevant details—closes the door to replication. Making the “right” decision, however, at best only clarifies and quantifies how much further away we remain from exact replication. Either way, the hubris implicit in any attempt to perfectly replicate a project is fated to fail.

Mimesis in John 13

Johannine scholarship is divided on whether the mimetic imperative in John 13:15 calls for a literal replication of the footwashing or is a general reference to humble (loving) service. My argument is that for the author mimesis involves primarily the creative, truthful, bodily articulation of the idea and attitude that lie behind the original act rather than its exact replication. The Johannine concept of mimesis is a hermeneutical process that involves both the understanding of the original act and a resulting mimetic act that creatively but faithfully articulates this understanding.

On the roles of repetition in language teaching and learning

Repetition is common in language use. Similarly, having students repeat is a common practice in language teaching. After surveying some of the better known contributions of repetition to language learning, I propose an innovative role for repetition from the perspective of complexity theory. I argue that we should not think of repetition as exact replication, but rather we should think of it as iteration that generates variation. Thus, what results from iteration is a mutable state. Iteration is one way that we create options in how to make meaning, position ourselves in the world as we want, understand the differences which we encounter in others, and adapt to a changing context.

Replication and extension of Little et al.'s (2003) forms and functions of aggression measure

The goal of the current study was to replicate the confirmatory factor analysis of Little et al.'s (2003) aggression measure in an American sample of 69 children (mean age = 12.93 years; SD = 1.27). Although an exact replication of the original model could not be estimated given the small sample, a modified model representing a conceptual replication provided a good fit to the data. Findings suggest that this child self-reported aggression measure can be used with American samples to distinguish four domains of aggressive behavior (relational, overt, instrumental, and reactive).

On the Replicability of the Affective Priming Effect in the Pronunciation Task

Bargh, Chaiken, Raymond, and Hymes (1996 ) and Hermans, De Houwer, and Eelen (1994 ) showed that a valenced target word is pronounced faster after the presentation of an affectively related prime word than after the presentation of an affectively unrelated prime word. This finding is important because it provides crucial evidence for the hypotheses that stimulus evaluation (a) is goal-independent and (b) facilitates the encoding of stimuli that have the same valence. However, recent studies indicate that the affective priming effect is not a reliable finding in the standard pronunciation task. We report the results of a nearly exact replication of Bargh et al.’s (1996 ) Experiment 2. In line with previous replication studies, we failed to detect the affective priming effect.