Frogs previously thought extinct resurface 

Plenty of resilient creatures exist in nature, having survived through events of mass extinction and numerous endemic diseases surrounding them. A recent study by Roland Knapp from UC Santa Barbara’s Earth Research Institute and collaborators investigated the newfound resistance of the Sierra Nevada yellow-legged (Rana sierrae) frog to a fungal pathogen called Batrachochytrium dendrobatidis, which has been devastating biodiversity in the animal kingdom. The pathogen has particularly affected Rana sierrae frogs, causing their population to decline significantly to the brink of endangerment. However, these frogs have found a way to fight back against the pathogen, as researchers have observed higher survival rates in new adults. 

In their study, scientists reintroduced Batrachochytrium dendrobatidis (Bd)-resistant frogs to other Rana sierrae populations recovering from Bd and observed the effects this had on the survival rates of populations. Along with this observation, the study also looked to determine what effect certain factors like body size, sex and amount of Bd present in the frogs had on these rates, as well as the long term behavior of the population. 

After placing some of these resistant frogs in larger populations, scientists used capture-mark-recapture surveys to count the number of tadpoles and observe the survival of these frogs over the course of 16 years. Results showed that the populations of Rana sierrae frogs had a higher survival rate, despite the continued presence of the pathogen. The lack of impact of environmental factors indicates that through the original re-introduced frogs, a resistance has successfully integrated into the population, with the new adult frogs having high chances of survival. The evidence that resistance is more commonly genetic in these frogs creates optimism for their long-term survival.  

A pathway to plastic reduction

Plastic pollution, in particular its wide-spread presence in our land and oceans, has been an ongoing issue. A recent study by UCSB researchers spanning across the Marine Science Institute, Bren School of Environmental Science & Management and the Department of Ecology, Evolution, & Marine Biology and collaborators predicts that global plastic consumption will rise by 37% if the majority of the world continues to use plastic at an increasing rate. 

Fortunately, these scientists have outlined eight policies in their paper that, if followed by governments throughout the world, would prevent the situation with plastic waste and consumption from escalating to the predicted degree. Small steps have been taken in terms of reducing plastic in the environment, however, they acknowledge that effective introduction of all eight of these policies is required for the desired impact on plastic waste. 

The policies that governments should enforce range from requiring 40% of all plastics be made from recycled materials, putting a cap on the amount of plastic that can be produced, strict re-packaging policies and preventing single-use packaging from being produced. Governments should also invest in new and more effective recycling infrastructure. 

The scientists have used a machine learning-based model to predict that plastic waste could be reduced by a significant 91% of the predicted amount by 2050 if all countries with plastic-intensive economies follow these policies. It is highlighted by their study that countries across the world must work to implement all of these policies into everyday life to effectively combat plastic pollution. 

Insights into cancer from animal studies

Current research in cancer has taken an interesting turn as researchers, including Amy Boddy from UCSB’s Department of Anthropology and collaborators, have conducted a large-scale study of cancer in 292 species of amphibians, reptiles, birds and mammals. The study is a comprehensive analysis of patterns in the factors and traits in animals that affect prevalence of cancers, or neoplasms, which is a broad term for both malignant and benign tumours. 

The study revealed that species with a longer gestation period have a lower risk of developing a neoplasm during their lifetime. In their paper, researchers speculate that this correlation may be due to more metabolism in these animals devoted to the development of somatic cells, rendering them less vulnerable to cancer. In addition, after correcting for the effects of varying gestation periods, the study yielded yet another interesting result that challenged the generally accepted Peto’s paradox, which states that cancer risk or incident is not related to the body mass of animals in any way. In fact, this study showed that larger animals were more susceptible to neoplasms than smaller animals. While there is insufficient data to fully reject Peto’s paradox, this result raises questions about its validity and paves the way for further investigation. 

Animals such as porpoises and the fruit bat have been identified as unique in their low susceptibility to cancer, and further investigation into cancer suppression mechanisms that these species have adopted could be vital for future cancer research. This study provides a baseline for exploring these trends in cancer susceptibility that can then be applied to the benefit of human beings. 

A version of this article appeared on p.9 of the Jan. 23, 2025 edition of the Daily Nexus.

Print