Why life looks as it looks?
My research centers around unraveling the dynamics of species evolution under changing environmental conditions, examining the processes and timing involved at local and global scales. I integrate a multidisciplinary approach, combining fieldwork, literature analysis, and museum collections with computer vision, biophysical models, spatial analyses, and phylogenetic comparative methods. Such holistic methodology allows me to explore how species adapt to shifting environments across time and space. My studies primarily focus on the adaptive biology of the colored integument in animals. This unique trait, responsible for functions like camouflage, communication, and thermoregulation, serves as a biological record of a species’ evolutionary journey. It comes clear then that studying the colored integument goes beyond aesthetics, offering insights into the ecological, behavioral, and evolutionary dynamics of the animal world.
Below, I provide an overview of my primary research and projects. For those seeking a quick summary, please visit the dedicated publication list page.
Macroevolution of the colored integument
How did ectotherms‘ colored integument evolve in response to thermal stressors?
Colors perform key functions in animals and over millions of years, they evolved to yield the current spectacular diversity.They are produced by the emission and/or reflectance of wavelengths (light) on the organism’s surface. While pigments and chromatophores represent well-known color-producing mechanisms, nature encompasses other structures capable of producing coloration, such as structural colors and bioluminescence. A main component of my PhD project described how the thermal properties of the colored integument evolved in ectotherms, using endemic South African lizards (Agamidae, Cordylidae) as study organisms. Together with a team, I spent 8 months in the field collecting more than 340 individuals. This has led to a series of publications showing the significance of color under different habitats and climate conditions. For example, we provided evidence that substrate type has a strong influence on shaping ventral color evolution of lizards (Goldenberg et al. 2023), where dark, melanin rich ventral colors positively associate with cold-humid substrates, suggesting a thermoregulatory role of this pigment. The results reinforce a previous study (Goldenberg et al. 2021), where we analyzed the color brightness of 126 viper species, and we showed that ventral brightness is influenced by substrate thermal properties.
Computer vision
Can we objectively classify features and patterns in animals?
Computer vision enables the automated analysis of vast amounts of visual data, such as images of organisms and their environments, allowing researchers to efficiently study evolutionary patterns and processes across diverse taxa and spatial scales. By leveraging advanced algorithms and machine learning techniques, computer vision facilitates the identification, classification, and measurement of morphological traits, helping researchers uncover subtle phenotypic variations and understand the adaptive significance of traits in evolutionary contexts. Using the spectacular diversity of pattern polymorphism (PP) in anole lizards, we are currently introducing a framework that combines a Java-based image processing program with convolutional neural network (CNN) for the automated, repeatable, and unbiased classification of PPs from digital images. This method efficiently acquires high-quality data, laying the foundation for understanding the adaptive processes behind female PPs in these lizards and offering insights into similar phenomena in other species. Watch this space for updates on this project!
Species responses to climate change
Can animals cope with rapid changing environments?
Climate change has an undeniable potential to modify ecosystem structures. With both its direct and indirect effects, populations’ dynamics are threatened from fluctuating environmental conditions. Data aquired in South Africa during my PhD was also used to produce biophysical models to evaluate how past, present, and future climate conditions will affect species’ activities. Overall, we found that warming scenarios alter lizard activity patterns across a latitudinal gradient (Goldenberg et al. Under Review) and that larger and darker populations are more susceptible to rising temperatures (Mader & Goldenberg et al. 2022). The findings propose that body size and melanin level should be used as proxies for these organisms to identify evolutionary significant units for conservation purposes. Moreover, I am particularly intrigued by the clustering of species worldwide and the potential correlations between their phenotypes and ecogeographical patterns. Over the past 150 years, numerous ecogeographical rules explaining the global distribution of animal morphologies in relation to climate have been proposed. Has the change in climate since these rules were first proposed reduced their utility? We argued that we should revise the use of ‘rules’, not only because it invokes patterns across time and space that are often not consistent at large taxonomic scales, but also because these rules were initially developed to explain macroecological patterns, while they are now used to predict changes in relation to fast, local climate changes to which they may not be applicable (Goldenberg et al. 2022).
Evolutionary trajectories of venomous animals and the potential pharmacological applications of toxins
Can diet shape the evolutionary trajectory of the venom system?
Venom can be described as a cocktail mixture of peptides, proteins, salts and few organic components. Over time, it appeared in multiple lineages, highlighting its evolutionary advantage. Integrating multiple disciplines ranging from ecology, evolutionary biology to functional genomics it is possible to understand the mechanisms underpinning the evolution of the venom system. As part of my MSc I investigated the variation of venom composition in Australian black snakes (Pseudechis spp.). Proteomics analyses and bioactivity testing were correlated to provide insight on venom evolution and potential pharmacological applications (Goldenberg et al. 2018). We showed that the typical Pseudechis venom profile is dominated by phospholipase A2 toxins. P. porphyriacus, the most basal member of the genus, also exhibited the most divergent venom composition, and had a relatively high presence of factor Xa which may be related to its predominantly amphibian diet. Moreover, we also found a lack of relationship between cytotoxicity to non-cancer and malignant melanoma cell lines suggesting that Pseudechis venom is a promising candidate for biodiscovery of novel anticancer drugs as it appears to typically contain toxins that selectively attack cancer cells.
This project was part of a large-scale study aiming to understand the evolution of the Australian front-fanged venomous snake (Elapidae). This led to publish a series of articles that tackle and question which driving forces played a key role in shaping such an outstanding elapids’ diversification. We investigated the venom composition of 28 species and for the first time in elapid snakes, we revealed the existence of an ontogenetic shift in the venom composition and activity of brown snakes (Pseudonaja sp.). For further information, see Jackson et al. 2016 and Cipriani et al. 2017.
Natural History
What can we learn from nature?
Natural history notes provide a blueprint for organism characteristics and interactions in their natural environments, serving as foundational data for evolutionary biology and broader eco-evo-devo research. They offer insights into species diversity, population dynamics, and ecological relationships. Species distribution models can complement natural history notes by predicting the geographic ranges of species based on environmental variables, aiding in conservation efforts and hypothesis generation regarding species responses to changing environmental conditions. Recently, we provided a new description and distribution of an enigmatic centipede thriving in Sicily (Faraone et al. 2024) which shows a strong correlation with arid environments.
