EEB Papers - Nelson Hairston

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https://hdl.handle.net/1813/57220

Professor Hairston studies freshwater organisms in lakes and their ecological and evolutionary response to environmental change. He is Frank H.T. Rhodes Professor of Environmental Science, past Chair of EEB, past Senior Associate Dean in Arts & Sciences, and a former member of the Cornell Board of Trustees. This archival collection represents just a sub-set of Prof. Hairston's publications. In some cases due to copyright restrictions we may only be able to share pre or "post-print" versions. Links to the actual published versions of each article (where available) can be found in the RELATED DOI field for each record.

A more complete and current listing of Prof. Hairston's work and scholarly output can be found on his EEB Department web page and the Hairston Lab web site, or through the links below.

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ORCID ID: https://orcid.org/0000-0002-0615-9843

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Now showing 1 - 10 of 21

Data from: Consumer-resource dynamics is an eco-evolutionary process in a natural plankton community
Schaffner, Lindsay; Govaert, Lynn; De Meester, Luc; Ellner, Stephen; Fairchild, Eliza; Miner, Brooks; Rudstam, Lars; Spaak, Piet; Hairston, Nelson (2019)
For an important consumer-resource interaction in a natural lake (Oneida Lake, New York State) in 2015, the ecological process of grazer population growth rate was a function of both evolutionary changing mean resistance of the grazer population in response to seasonal change in the quality of their phytoplankton food, as well as ecologically changing total phytoplankton density. While rapid evolution on the time scale of ecological interactions has been shown in the past to underlie eco-evolutionary dynamics using mathematical models, laboratory microcosms and mesocosms, our study is among the very first to demonstrate the importance of these processes in nature. Cyanobacterial blooms (commonly called “harmful algal blooms” or “HABS”) are of increasing concern in waterbodies world-wide, and our study contributes to an often overlooked component of system response: rapid evolution and its feedbacks on plankton dynamics. We combine genetic identification of clonal genotypes using molecular markers (showing evolutionary clonal succession in a natural lake ecosystem) with laboratory measurements of ecologically important genetic differences among clones in their tolerance of a late-summer cyanobacterial bloom. This folder contains files with data and analyses underlying all of the figures and tables presented in a manuscript submitted for publication.
The interaction of photoperiod and temperature in diapause timing: a copepod example
Hairston, Nelson G., Jr.; Kearns, C. M. (University of Chicago Press, 1995-08)
In many organisms, photoperiod and temperature are thought to be the most significant token cues for seasonally timed life history events, including diapause in arthropods. A common pattern in many species of terrestrial insects and several copepod species is the existence of a critical daylength on one side of which the animals do not enter diapause and on the other side of which they do. Temperature plays a secondary role as modifier of the critical daylength. In some species, however, including the freshwater copepod Diaptomus sanguineus, the fraction of females making subitaneous eggs (eggs that hatch immediately) undergoes a very gradual transition as daylength changes over the natural range of photoperiods experienced in nature. Here we show that temperature is as important as photoperiod in cuing diapause timing in a population of D. sanguineus living in Bullhead Pond, Rhode Island. When ecologically relevant photoperiod and temperature cues are provided in the laboratory, the copepods rapidly switch from producing subitaneous eggs to producing diapausing eggs in a way that is typical of the seasonal switch seen in the pond. We provide a graphical model that illustrates how copepod sensitivities to photoperiod and temperature interact to produce an abrupt transition, and we discuss how natural selection should act on D. sanguineus diapause response to produce the variation in diapause timing seen within and between natural populations.
The timing of copepod diapause as an evolutionarily stable strategy
Hairston, Nelson G., Jr.; Munns, Wayne R. (University of Chicago, 1984-06)
Diaptomus sanguineus, a small freshwater copepod, avoids periods of intense fish predation by producing diapausing eggs. We developed a computer simulation of the copepod's life history and used it to compete populations that switched to diapause at different intervals of time before the onset of fish predation (the catastrophe). With no variation about the catastrophe date, the evolutionarily stable strategy (ESS) is one in which the switch to diapause comes exactly one generation before the catastrophe, as Taylor (1980) has shown analytically. With increasing variation about the catastrophe date, the ESS becomes one of switching to diapause at time intervals increasingly greater than one generation. Using field data on copepod mortality rates from 5 yr, we have estimated the mean and variance about the catastrophe date. Using field and laboratory data, we have estimated the copepod generation time and the timing of the switch to diapause. We find, in close agreement with simulation-derived ESSs, that D. sanguineus starts making diapausing eggs 1.3 generations before the major onset of fish-induced mortality.
Temporal dynamics of a simple community with intraguild predation: an experimental test
Hiltunen, T.; Jones, L. E.; Ellner, S. P.; Hairston, Nelson G., Jr. (Ecological Society of America, 2013-04)
We explore how adding complexity to a typical predator-prey interaction affects temporal dynamics. Intraguild predation webs contain competition, predation, and omnivory in a system of three species where theory and empirical results can be compared. We studied a planktonic microcosm community in which an alga is consumed by a flagellate and by a rotifer that also consumes the flagellate. Previously published theory predicts that phase lags between the species are the outcome of a "tug of war" among the intraguild-predation links: rotifers-algae, flagellates-algae, and rotifers-flagellates. We observed sustained oscilltions with abundance peaks that corresponded exactly to theoretical predictions in all replicates: peaks of the rotifers and flagellates fell on either side of a quarter-period lag behind the prey (algae) peaks, with the peak of the intermediate predator (flagellates) preceding that of the top predator (rotifers). The phase lags in these experiments suggest that temporal variation in flagellate growth rate is primarily driven by variation in the intensity of its consumption by rotifers, rather than by variation in the density of its algal prey. This system illustrates how interaction strength affects the pattern of intraguild predation cycles and provides an opportunity to explore how evolution of interaction strength may affect those dynamics.
Role of overlapping generations in maintaining genetic variation in a fluctuating environment
Ellner, Stephen; Hairston, Nelson G., Jr. (University of Chicago, 1994-03)
Population genetics theory suggests that temporally fluctuating selection on pheno- types can act to maintain genetic variance only under very restrictive conditions. However, this conclusion is based on models with discrete nonoverlapping generations. We propose here that temporally fluctuating selection can indeed contribute significantly to the maintenance of genetic variation when the effects of overlapping generations and age-specific or stage-specific selection are considered. We develop a simple model for a population with overlapping generations, experiencing stabilizing selection with a temporally fluctuating optimum, and subject to repeated invasions by mutants with alternative phenotypes. We find that an evolutionarily stable popula- tion must have positive genetic variance maintained by selection so long as the product (variance of fluctuations) times (amount of generation overlap) times (selection intensity) is sufficiently high. This result applies to haploid, diploid, single-locus, or multilocus inheritance, and it does not depend on any form of heterozygote advantage to maintain genetic variance. However, it depends on the map between genotype and phenotype being constrained. If a single genotype can produce an arbitrary distribution of phenotypes, then genetic variance is not maintained by selection.
Species-specific Daphnia phenotypes: a history of industrial pollution and pelagic ecosystem response
Hairston, Nelson G., Jr.; Kearns, Colleen M.; Perry Demma, Linda; Effler, Steven W. (Ecological Society of America, 2005-07)
Phenotypic differences among species, even closely related species, may translate into distinct effects on ecosystem dynamics. In lakes, the generalist grazer genus Daphnia often has marked effects on the abundance of primary producers, the rate of primary production, and rates of nutrient cycling. The effects are particularly distinct during the clear-water phase (CWP) when algal biomass is driven to extremely low values as Daphnia densities undergo an annual population increase. Here we show that the timing of the CWP in Onondaga Lake, New York, USA, has depended upon which Daphnia species were present in the water column. An analysis of the ephippia and diapausing eggs from the sediments reveals that long-term changes in the zooplankton species assemblage tracks a history of chemical (especially salt waste) pollution. Prior to 1930 the assemblage was dominated by native D. pulicaria and D. ambigua. From 1930 to 1980, these species were replaced by D. exilis and D. curvirostris, two salinity-tolerant exotic species native to shallow salt pools of the southwestern United States and coastal brackish ponds of Europe, respectively. As industry was progressively shut down by government action over the period from the 1970s to the 1980s, the exotic species disappeared, and the two native taxa returned (plus D. galeata mendotae, which is also native to the region). As we have shown previously, the exotic species were identified either by hatching and rearing diapausing eggs (D. exilis) or by analysis of eggs using mtDNA (D. curvirostris). We interpret their role in seasonal algal dynamics in Onondaga Lake retrospectively using data collected in prior studies of the lake. The native Daphnia currently cause a typical spring CWP in late May and early June, whereas the exotic species caused an unusual late-summer (August-October) CWP during the period of maximum cyanobacterial density.
Photoprotection by carotenoid pigments in the copepod Diaptomus nevadensis
Hairston, Nelson G., Jr. (National Academy of Sciences, 1976-03)
Individuals of the copepod Diaptomus nevadensis that contain high concentrations of carotenoids survive significantly better in natural intensities of visible light than less pigmented copepods. Vertical migration and behavior in light of different wave lengths are related to the degree of pigmentation.
Rapid evolution of a life-history trait
Hairston, Nelson G., Jr.; Walton, W. E. (National Academy of Sciences, 1986-07)
The copepod Diaptomus sanguineus begins diapause in permanent ponds in late March as an adaptation to avoid summer fish predation. During a study of copepod populations in two Rhode Island ponds, a severe drought dried one pond killing all fish. The second (control) pond did not dry, and no fish were killed. Before the drought copepods in the two ponds entered diapause on nearly the same date. After the drought, the timing of diapause shifted to later in the year in the pond that had lost its fish, while no shift occurred in the control pond. The direction of this shift in the onset of diapause is that expected had the copepods been released from natural selection for early spring diapause imposed by summer fish predation.
Prey evolution on the time scale of predator-prey dynamics revealed by allele-specific quantitative PCR
Meyer, J. R.; Ellner, S. P.; Hairston, Nelson G., Jr.; Jones, L. E.; Yoshida, T. (National Academy of Sciences, 2006-07-11)
Using rotifer-algal microcosms, we tracked rapid evolution resulting from temporally changing natural selection in ecological predator-prey dynamics. We previously demonstrated that predator-prey oscillations in rotifer-algal laboratory microcosms are qualitatively altered by the presence of genetic variation within the prey. In that study, changes in algal gene frequencies were inferred from their effects on population dynamics but not observed directly. Here, we document rapid prey evolution in this system by directly observing changes in Chlorella vulgaris genotype frequencies as the abundances of these algae and their consumer, Brachionus calyciflorus, change through time. We isolated a group of algal clones that we could distinguish by using microsatellite-DNA markers, and developed an allele-specific quantitative PCR technique (AsQ-PCR) to quantify the frequencies of pairs of clones in mixed culture. We showed that two of these genotypes exhibited a fitness tradeoff in which one was more resistant to predation (more digestion-resistant), and the other had faster population growth under limiting nitrogen concentrations. A fully specified mathematical model for the rotifer-algal population and evolutionary dynamics predicted that these two clones would undergo a single oscillation in clonal frequencies followed by asymptotic fixation of the more resistant clone, rather than the recurrent oscillations previously observed with other algal clones. We used AsQ-PCR to confirm this prediction: the superior competitor dominated initially, but as rotifer densities increased, the more predator-resistant clone predominated.
Partial photoperiodic control of diapause in three populations of the freshwater copepod Diaptomus sanguineus
Hairston, Nelson G., Jr.; Olds, Emily J. (University of Chicago Press, 1986-08)
Populations of the freshwater calanoid copepod Diaptomus sanguineus inhabiting three Rhode Island ponds switch from making subitaneous (immediately hatching) to diapausing eggs on different dates. From results of previous research the timing of diapause appears to correspond closely to the individual causes of seasonally harsh conditions in each pond. The results of rearing copepods from each pond in controlled laboratory environments indicate that each population possesses a unique spectrum of sensitivity to photoperiod. The responses obtained, however, fail to describe adequately either the rapidity with which the onset of diapause occurs in natural populations, or the differences in diapause timing between ponds. In initiating diapause, the copepods must respond to seasonal environmental cues other than critical photoperiod.

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