Author: Kristin Winchell Page 2 of 8

I am an Assistant Professor of Biology at New York University. My first love is herpetology, but my lab works on urban evolutionary ecology in diverse organisms (but primarily anoles!).

Thermal Sensitivity of Lizard Embryos Indicates a Mismatch Between Oxygen Supply and Demand at Near-lethal Temperatures

New literature alert!

In Journal of Experimental Zoology
Hall and Warner

Abstract

Aspects of global change create stressful thermal environments that threaten biodiversity. Oviparous, non‐avian reptiles have received considerable attention because eggs are left to develop under prevailing conditions, leaving developing embryos vulnerable to increases in temperature. Though many studies assess embryo responses to long‐term (i.e., chronic), constant incubation temperatures, few assess responses to acute exposures which are more relevant for many species. We subjected brown anole (Anolis sagrei) eggs to heat shocks, thermal ramps, and extreme diurnal fluctuations to determine the lethal temperature of embryos, measure the thermal sensitivity of embryo heart rate and metabolism, and quantify the effects of sublethal but stressful temperatures on development and hatchling phenotypes and survival. Most embryos died at heat shocks of 45°C or 46°C, which is ~12°C warmer than the highest constant temperatures suitable for successful development. Heart rate and O2 consumption increased with temperature; however, as embryos approached the lethal temperature, heart rate and CO2 production continued rising while O2 consumption plateaued. These data indicate a mismatch between oxygen supply and demand at high temperatures. Exposure to extreme, diurnal fluctuations depressed embryo developmental rates and heart rates, and resulted in hatchlings with smaller body size, reduced growth rates, and lower survival in the laboratory. Thus, even brief exposure to extreme temperatures can have important effects on embryo development, and our study highlights the role of both immediate and cumulative effects of high temperatures on egg survival. Such effects must be considered to predict how populations will respond to global change.

 

Hall, JM, Warner, DA. Thermal sensitivity of lizard embryos indicates a mismatch between oxygen supply and demand at near‐lethal temperatures. J Exp Zool. 2020; 114.

 

Anolis cristatellus Journal Cover!

Hot off the press — the latest anole journal cover! In this issue of Nature Ecology & Evolution, Shane Campbell-Staton and I led a team of researchers to explore the effects of urban heat islands on anoles. We found that not only can urban Anolis cristatellus tolerate higher temperatures than their forest counterparts, but also identified genomic regions associated with divergent thermal tolerance. Check out a summary of this work at the urban evolution blog I co-edit, Life in the City: Anoles Adapt to Beat the Urban Heat.

Anole Online Learning Resources

The days of self-isolation and quarantine are dragging on as COVID-19 continues its worldwide rampage. We may all be a little less productive than we had thought we would be as we tend to unruly kids and rogue parents who won’t stay indoors. Here at Anole Annals, we’ve scoured our past posts and brainstormed some of our favorite learn-at-home resources to help keep you entertained at home while learning about your favorite lizards!  Whether you’re a seasoned researcher looking for a break, a teacher in search of remote learning activities, or a parent at home with kids in need of educational activities, we hope you find the following resources useful.

 

HHMI BioInteractive

HHMI produced several fantastic videos and learning modules perfect for learning about anoles, ecology, and evolution in the classroom and at home! Each of the activities also comes with handy educator materials to make sure your newly homeschooled students gets the most out of these resources.

The Origin of Species: Lizards in an Evolutionary Tree — This short video (~17 minutes) covers the concepts of adaptation, islands as natural laboratories, speciation, and convergent evolution. Pair the video with the associated interactive activities and discussion prompts to get the most out of this resource. Start with this one, since all of the other activities produced by HHMI relate back to the concepts covered here.

Lizard Evolution Virtual Lab — This all inclusive four part learning module involves videos and an interactive web application (also available for IOS) to learn about ecomorphs, phylogenies, experimental data, and dewlaps. Students will collect and analyze data as they learn about the scientific process and anole themed concepts. The modules also have embedded mini quizzes to make sure your student is understanding the information, and educator materials to help you guide your students as they learn.

The Lone Anole — This activity is a short conversation starter based on a photo of the Plymouth anole (Anolis lividus) to use with students to discuss ideas of adaptation and natural selection.

One of the sample cards for students to “collect data” from in the HHMI  selection by predation activity.

Look Who’s Coming for Dinner: Selection by Predation — In this interactive activity, students are walked through the scientific process to learn how to develop a hypothesis, collect data, and analyze results with plotting and basic statistics. This activity is based on the study: Rapid temporal reversal in predator-driven natural selection (Losos et al. 2006). Everything you need to complete the virtual experiment is included!

Effects of Predation on the Niche of Lizards — This short activity guides students through interpreting a scientific figure from the study: Predation on a common Anolis lizard: can the food- web effects of a devastating predator be reversed? (Schoener, Spiller, and Losos, 2002).

How Lizards Find Their Way Home — This short video (8 minutes) is based on the research of Manuel Leal. Watch a real scientist design an experiment to answer a question and carry out fieldwork radio tracking lizards! Produced by Day’s Edge Productions.

Lizards in the Cold — This short activity based on the study Winter storms drive rapid phenotypic, regulatory, and genomic shifts in the green anole lizard (Campbell-Staton et al. 2017) teaches students how to interpret a scientific figure and is a good conversation starter for discussing natural selection and climate change.

Lizards in Hurricanes — Another short activity based on a study by Donihue et al. (2018): Hurricane-induced selection on the morphology of an island lizard. Students are asked to review a figure from the paper and discuss how hurricanes and other extreme weather events can lead to morphological change, and how scientists can experimentally investigate these changes.

Reproductive Isolation and Speciation in Lizards — This short animated video (~2 minutes) discusses the process of speciation and the role of the dewlap in reproductive isolation in anoles.

Using DNA to Explore Lizard Phylogeny — In this interactive activity students learn how to build a phylogeny based on common traits and then by using DNA sequences to explore the concept of convergent evolution. As with the other activities, everything you need to do this experiment at home is provided digitally.

Recent Biological Invasion Shapes Species Recognition and Aggressive Behaviour in a Native Species: A Behavioural Experiment Using Robots in the Field

New literature alert!

In Journal of Animal Ecology
Dufour, Clark, Herrel, and Losos

Abstract

 

  1. Invasive species are a world‐wide threat to biodiversity. Yet, our understanding of biological invasions remains incomplete, partly due to the difficulty of tracking and studying behavioural interactions in recently created species interactions.
  2. We tested whether the interactions between the recently introduced invasive lizard Anolis cristatellus and the native Anolis oculatus in Dominica have led to changes in species recognition and aggressive behaviour of the native species.
  3. The use of realistic robots allowed us to test the behavioural response of 131 A. oculatus males towards relevant and controlled conspecific versus heterospecific stimuli, directly in the field and in two contexts (allopatry vs. sympatry).
  4. Our results show that species recognition evolved prior to sympatry in A. oculatus. Moreover, interspecific competition resulted in an increase in the time spent displaying and a divergence in the aggressive behaviour of the native species towards conspecifics versus heterospecifics. Inherent species recognition and higher aggressive behaviour may limit species coexistence as they are expected to favour A. oculatus during territorial interactions with A. cristatellus.
  5. While more studies are needed to understand the causes of these behavioural shifts and their consequences on long‐term species coexistence, the present study highlights the role of behaviour as a first response to interspecific interactions.

 

 

Dufour, C. M., Clark, D. L., Herrel, A., & Losos, J. B. (2020). Recent biological invasion shapes species recognition and aggressive behavior in a native species: a behavioral experiment using robots in the field. Journal of Animal Ecology.

Prevalence of Salmonella in Green Anoles (Anolis carolinensis), an Invasive Alien Species in Naha and Tomishiro Cities, Okinawa Main Island, Japan

New literature alert!

In Journal of Veterinary Medical Science
Sumiyama, Shimizu, Kanazawa, Anzai, and Murata

Abstract

Here, we investigated the prevalence of Salmonellaenterica, with and without resistance to 17 common antimicrobial agents, in 706 green anoles (Anolis carolinensis) that were collected in Naha and Tomishiro Cities, Okinawa Main Island, Japan, between 2009 and 2014. Salmonella strains, including S. enterica Weltevreden and Enteritidis serovars, were identified in the large intestinal content samples extracted from 15 (2.1%) of the analyzed green anoles. No antimicrobial resistance was detected. Thus, the present study demonstrates that although the prevalence of Salmonella and the risk of its transmission from the green anoles to humans or other animals on Okinawa Main Island are relatively low, the green anole population nevertheless represents a potential source of Salmonella infection that could affect human health in this region.

 

SUMIYAMA, D., SHIMIZU, A., KANAZAWA, T., ANZAI, H., & MURATA, K. (2020). Prevalence of Salmonella in green anoles (Anolis Carolinensis), an invasive alien species in Naha and Tomishiro Cities, Okinawa Main Island, Japan. Journal of Veterinary Medical Science, 19-0594.

Parallel Selection on Thermal Physiology Facilitates Repeated Adaptation of City Lizards to Urban Heat Islands

New literature alert!

In Nature Ecology and Evolution
Campbell-Staton, Winchell, Rochette, Fredette, Maayan, Schweizer, and Catchen

Abstract

Only recently have we begun to understand the ecological and evolutionary effects of urbanization on species, with studies revealing drastic impacts on community composition, gene flow, behaviour, morphology and physiology. However, our understanding of how adaptive evolution allows species to persist, and even thrive, in urban landscapes is still nascent. Here, we examine phenotypic, genomic and regulatory impacts of urbanization on a widespread lizard, the Puerto Rican crested anole (Anolis cristatellus). We find that urban lizards endure higher environmental temperatures and display greater heat tolerance than their forest counterparts. A single non-synonymous polymorphism within a protein synthesis gene (RARS) is associated with heat tolerance plasticity within urban heat islands and displays parallel signatures of selection in cities. Additionally, we identify groups of differentially expressed genes between habitats showing elevated genetic divergence in multiple urban–forest comparisons. These genes display evidence of adaptive regulatory evolution within cities and disproportionately cluster within regulatory modules associated with heat tolerance. This study provides evidence of temperature-mediated selection in urban heat islands with repeatable impacts on physiological evolution at multiple levels of biological hierarchy.

 

Campbell-Staton, S. C., Winchell, K. M., Rochette, N. C., Fredette, J., Maayan, I., Schweizer, R. M., & Catchen, J. (2020). Parallel selection on thermal physiology facilitates repeated adaptation of city lizards to urban heat islands. Nature Ecology & Evolution, 4(4), 652-658.

Phylogenetic Signal and Evolutionary Correlates of Urban Tolerance in a Widespread Neotropical Lizard Clade

New literature alert!

In Evolution
Winchell, Schliep, Mahler, Revell

Abstract

Urbanization is intensifying worldwide, and while some species tolerate and even exploit urban environments, many others are excluded entirely from this new habitat. Understanding the factors that underlie tolerance of urbanization is thus of rapidly growing importance. Here, we examine urban tolerance across a diverse group of lizards: Caribbean members of the neotropical genus Anolis. Our analyses reveal that urban tolerance has strong phylogenetic signal, suggesting that closely related species tend to respond similarly to urban environments. We propose that this characteristic of urban tolerance in anoles may be used to forecast the possible responses of species to increasing urbanization. In addition, we identified several key ecological and morphological traits that tend to be associated with tolerance in Anolis. Specifically, species experiencing hot and dry conditions in their natural environment and those that maintain higher body temperatures tend to have greater tolerance of urban habitats. We also found that tolerance of urbanization is positively associated with toepad lamella number and negatively associated with ventral scale density and relative hindlimb length. The identification of factors that predispose a species to be more or less urban tolerant can provide a starting point for conservation and sustainable development in our increasingly urbanized world.

 

Winchell, K. M., Schliep, K. P., Mahler, D. L., & Revell, L. J. (2020). Phylogenetic signal and evolutionary correlates of urban tolerance in a widespread neotropical lizard clade. Evolution.

The Hypothalamic-Pituitary-Gonadal Axis and Thyroid Hormone Regulation Interact to Influence Seasonal Breeding in Green Anole Lizards (Anolis carolinensis)

New literature alert!

In General and Comparative Endocrinology
Kang, Kenealy, and Cohen

Abstract

Reproductive physiology and behavior is mainly regulated by the hypothalamus-pituitary-gonad (HPG) axis, although abnormal thyroid hormone (TH) levels alter HPG axis activity. Seasonally breeding animals, such as green anole lizards (Anolis carolinensis), undergo drastic hormonal and behavioral changes between breeding and non-breeding seasons, with increased sex steroid hormones, larger gonads and increased reproductive behaviors during the breeding compared to non-breeding seasons. Relatively less is known regarding the regulation of gonadal TH in seasonal reproduction. We examined whether the gonadal expression of enzymes involved in TH activation are altered in concert with seasonal reproduction. Type 2 deiodinase (Dio2) mRNA, the TH activating enzyme, was upregulated in breeding compared to non-breeding testes, while type 3 deiodinase (Dio3) mRNA, the TH deactivating enzyme, was upregulated in breeding ovaries. To study the association between the HPG axis and local activation of TH, we manipulated the HPG axis during the non-breeding season by subcutaneously injecting luteinizing hormone (LH) and follicle stimulating hormone (FSH) in male lizards. We found that acute LH and FSH injections induced many aspects of breeding, with increased testes size and testosterone levels. Surprisingly, Dio3 was upregulated in the testes after LH and FSH injections, while Dio2 mRNA levels were unchanged. These results suggest that there might be different roles for local TH activation in developing and maintaining fully mature and functional gonads. Our findings continue to support the role for TH in regulating reproduction.

 

Kang, H., Kenealy, T. M., & Cohen, R. E. (2020). The hypothalamic-pituitary-gonadal axis and thyroid hormone regulation interact to influence seasonal breeding in green anole lizards (Anolis carolinensis). General and Comparative Endocrinology, 113446.

Fluoridation of a Lizard Bone Embedded in Dominican Amber Suggests Open-system Behavior

New literature alert!

In PLoS One
Barthel, Fougerouse, Geisler, and Rust

Abstract

Vertebrate fossils embedded in amber represent a particularly valuable paleobiological record as amber is supposed to be a barrier to the environment, precluding significant alteration of the animals’ body over geological time. The mode and processes of amber preservation are still under debate, and it is questionable to what extent original material may be preserved. Due to their high value, vertebrates in amber have never been examined with analytical methods, which means that the composition of bone tissue in amber is unknown. Here, we report our results of a study on a left forelimb from a fossil Anolis sp. indet. (Squamata) that was fully embedded in Miocene Dominican amber. Our results show a transformation of the bioapatite to fluorapatite associated with a severe alteration of the collagen phase and the formation of an unidentified carbonate. These findings argue for a poor survival potential of macromolecules in Dominican amber fossils.

 

Barthel, H. J., Fougerouse, D., Geisler, T., & Rust, J. (2020). Fluoridation of a lizard bone embedded in Dominican amber suggests open-system behavior. PloS one, 15(2), e0228843.

The (Dis)advantages of Dominance in a Multiple Male Group of Anolis carolinensis Lizards

New literature alert!

In Zoology
Borgmans, Van den Panhuyzen, and Van Damme,

Abstract

Male Anolis carolinensis lizards will fight and form social dominance hierarchies when placed in habitats with limited resources. Dominance may procure benefits such as priority access to food, shelter or partners, but may also come with costs, such as a higher risk of injuries due to aggressive interaction, a higher risk of predation or a higher energetic cost, all of which may lead to an increase in stress. While most research looks at dominance by using dyadic interactions, in our study we investigated the effect of dominance in a multiple male group of A. carolinensis lizards. Our results showed that dominant males in a multiple male group had priority access to prey and potential sexual partners but may run a higher risk of predation. We could not confirm that dominant males in a multiple male group had a higher risk of injuries from aggressive interactions or a higher energetic cost by being dominant. Overall our results seem to indicate that dominant male A. carolinensis lizards in a multiple male group obtain clear benefits and that they outweigh the disadvantages.

 

Borgmans, G., Van den Panhuyzen, S., & Van Damme, R. (2020). The (dis) advantages of dominance in a multiple male group of Anolis carolinensis lizards. Zoology, 139, 125747.

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