Brittany Cavazos – Everyday Evolution, Evolution Every Day

April 15, 2024

The Evolution of Acoustic Signals in Poison Dart Frogs

By: Lia Casey, Jenna Cuzziere, and Rofail Wassef (Stonehill College, BIO 323: Evolution, Spring 2024)

Overview

Poison dart frogs, belonging to the Dendrobatidae family, are a fascinating group of amphibians renowned for their vibrant colors and potent toxins. These frogs are native to the tropical rainforests of Central and South America, where they inhabit diverse habitats ranging from leaf litter on the forest floor to the canopy of trees. Their striking hues, which include shades of red, blue, yellow, orange, and green, serve as a warning to potential predators of their toxic nature. Along with changing colors, poison dart frogs also can utilize acoustic signals (noises animals produce) to attract potential mates. Despite their small size, these frogs can produce a wide array of calls, ranging from simple chirps to complex series of notes. Male poison dart frogs often use their calls to establish and defend territories, as well as to attract mates during the breeding season. Each species has its unique call, which helps in species recognition and mate selection. Additionally, acoustic signals may also serve as a form of communication between males and females during courtship rituals, or mate selection, aiding in the coordination of reproductive behaviors. The frequency, duration, and intensity of these calls can convey information about the caller’s size, health, and vigor, influencing the outcome of mating interactions. Furthermore, studies have shown that environmental factors such as temperature and humidity can impact the acoustic properties of these calls, highlighting the intricate interplay between biology and the environment in the vocal behavior of poison dart frogs. Feel free to tune into the podcast to learn more about this exciting topic!

Short podcast summarizing the paper. Image of a Poison dart frog. Acoustic signals in poison dart frogs serve as vital communication tools for territorial defense, mate attraction, and courtship rituals within their diverse rainforest habitats. https://www.britannica.com/science/animal-communication/Signal-production
Podcast Music: https://www.youtube.com/watch?v=498HcLwcjxs

April 15, 2024

Unveiling the Secrets of Lizard Color Divergence

By: Priscilla Younes, Neyana Fortes, and Jordan Marot (Stonehill College, BIO323: Evolution, Spring 2023)

Overview

In the contrasting environments of the alpine meadows and sand dunes of the Qinghai-Tibet Plateau, two lizard populations have a secret weapon: the ability to use their body color for camouflage and thermoregulation, a local adaptation that helps them survive. Not only have these lizards adapted their colors to hide from predators, but they’ve also regulated their internal temperature using melanin-producing genes. In “Genetically Encoded Lizard Color Divergence for Camouflage and Thermoregulation,” Sun and his team show how the power of local adaptation allows separate populations of toadhead agamas (Phrynocephalus putjatai) to thrive in two distinct habitats. Their study highlights the importance of local adaptation, where species develop traits suited to their specific environments, and how it can lead to the divergence of species to create a new one. With combined data from field observations, genetic analyses, and other experiments, we aim to explain why the lizards developed different colors and how this enhances their survival. Tune into the Evolution Unraveled podcast for a deeper dive into this concept!

Short podcast summarizing paper. Photo from https://www.inaturalist.org/taxa/109362-Phrynocephalus-putjatai/browse_photos

April 15, 2024

Tadpole Adaptations to Increasing Temperatures in Urban Environments

By: Mallory Crispens, Sarah Faley, and Lilly Leach (Stonehill College, Bio323: Evolution Spring 2024)

Overview

One of the most beneficial characteristics for survival in the natural world is the ability to adapt to changing environments. In the face of climate change and increasing urbanization of rural areas, it has become even more important for wildlife to be able to adapt and endure increasing temperatures. Urban heat islands are a significant consequence of urbanization, occurring when cities replace natural land cover with dense concentrations of pavement, buildings, and other surfaces that absorb and retain heat. These heat islands create a brand-new environment for wildlife, particularly for pond-dwelling animals such as tadpoles whose aquatic environment is sensitive to change. While most organisms living in urban environments have elevated tolerance to heat, the thermal adaptations of aquatic organisms are relatively unknown. In the article, “Tadpoles Develop Elevated Heat Tolerances in Urban Heat Islands Regardless of Sex”, Dr. Bokony analyzes tolerance to increasing temperature, as a result of urbanization, in tadpoles.

A short podcast summarizing the article. Soundtrack image from https://scx2.b-cdn.net/gfx/news/2017/tadpole.jpg

November 27, 2023

The Benefits of Commitment in Black-headed Gulls

By: Karina Rodrigues, Joanna Soliman, Yenifer Oseguera, and Giana Youssef (Stonehill College, BIO323: Evolution, Spring 2023)

Overview

Loyalty, a quality some lack and some do not. Have you ever thought about the positive effects loyalty has on people, better yet species? In terms of evolution, loyalty translates to how committed a species is to its breeding partner. Originating from the Netherlands, black-headed gulls (Chroicocephalus ridibundus) were used to study the benefits of long-term relationships and if it plays a role in how parents invest more with their partners as well as their pair bond with one another. These seabirds were studied in a model environment that fits the birds natural needs in order to exhibit their natural behaviors. After testing different mechanisms, selection for mate retention reduces parental care conflicts between a pair and also sheds light to selecting traits that increase individuals fitness throughout evolution.

A short podcast summarizing the article.

November 27, 2023November 28, 2023

The Response to Extinction Level Disasters in Black Flying Foxes and their Diverse Genetic Background

By: Conner Dagge, James Harrington, Jason Webber, Liam Zizza (Stonehill College, BIO323: Evolution, Fall 2023)

Overview

We as humans are a part of the class Mammalia, a distinct class of animals that are recognized by hair on their bodies and mammary glands to produce milk. Bats are the only mammal that is capable of prolonged flight but maintains the other identifiable traits of the mammal. The Black Flying Fox (Pteropus alecto) is a species of bat is found in Oceania countries of Australia and Papua New Guinea. It is also found in In the Southeast Asian country of Indonesia. The Black Flying Fox is characterized by a high amount of genetic diversity and its ability to survive extreme natural disasters through adaptation. This information is provided by the article, “Population genomic analysis reveals distinct demographics and recent adaptation in the black flying fox (Pteropus alecto)”. In this article it cites direct evidence for how these unique bats have high genetic diversity compared to other mammals and how they likely survived a possible extinction event thousands of years ago.

A short podcast summarizing the article. Image from: https://commons.wikimedia.org/wiki/File:Flying-Fox-Bat.jpg

November 27, 2023November 28, 2023

Exploring the evolution of aestivation in turtles: unraveling the relation between their morphological traits with their aestivation time

By: Elizabeth Parkinson, Madison Barrett, Nathanaelle Brignol, and Robert Branco
(Stonehill College, BIO323: Evolution, Spring 2023)

Overview

Hibernation, or winter dormancy, is a well-known biological process. It is well represented in different forms of media and cultural traditions, such as children’s books and Groundhog Day. However, aestivation, or summer dormancy, is a lesser-known biological process. Similar to hibernation, organisms that undergo aestivation experience a state of decreased physiological activity over a prolonged period. It is considered by many scientists to be a strategy for surviving hot and dry seasons when water is hard to come by, and it is carried out by many species of reptiles and amphibians, among other classes of animals. A research article titled, “How Aestivation Evolved in Turtles: A Macroevolutionary and Morphological Approach,” explores how this trait evolved in many different species of turtless. It also studies the link between the length of aestivation undergone by a turtle and the structure of that turtle’s shell. They found that rather than occurring in a single ancestral species to all turtles, aestivation independently evolved in two different turtle clades. They also found that shell structure is related to aestivation time in varying ways across different families of turtles. This result indicates that a turtle’s environment may also influence their aestivation time. To learn more about aestivation in turtles, read more below, or listen to our podcast above!

A short podcast summarizing the article. Image credit: https://study.com/academy/lesson/estivation-definition-examples.html

November 27, 2023November 28, 2023

How Body Size and Proportionality are Influenced by Climate Change

By: Cameron Ward, Kellie Guerette, Meghan Doherty, and Benjamin Clark
(Stonehill College, BIO323: Evolution, Fall 2023)

Overview

Climate change is defined as long-term shifts in temperatures and weather patterns. Shifts can be natural, however, since the 1800s, human activities have been the main driver primarily due to the burning of fossil fuels. An article titled, “Climate Change Predictive of Body Size and Proportionality in Humans”, discusses how these changes have impacted the evolution of the human body over time. A relationship has been established between climate change and the human body shape and size, driven by natural selection in response to thermoregulatory demands. The studies suggested that smaller bodies with more of their weight distributed to the limbs dissipate heat better than larger and more rotund bodies with less relative surface area. This leads to larger species (endomorphic) in cooler geographic regions and smaller (ectomorphic) in warmer climates. Fossil records have shown that this trend holds true for a variety of species. Invertebrates, insects, and mammals all shrunk during past periods of global warming. Periods of global cooling have had the opposite effect, in which species increased in size to become better fit for their environment. There are several factors that could lead to the observed changes in body weight/ proportionality, however, climate change seems to be a major driver.

A short podcast summarizing the article.