The Benefits of Commitment in Black-headed Gulls

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


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.
Continue reading “The Benefits of Commitment in Black-headed Gulls”

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)


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:
Continue reading “The Response to Extinction Level Disasters in Black Flying Foxes and their Diverse Genetic Background”

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)


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

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)


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.
Continue reading “How Body Size and Proportionality are Influenced by Climate Change”

Parallel Evolution of Avoidance Behaviors Exhibited by Freshwater and Marine Sticklebacks

By: Moussa Abboud, Victoria Pinaretta, Jack Ryan, and Cameron Sarkisian (Stonehill College, BIO323: Evolution, Spring 2023)

Just as natural selection acts on land, the creatures of the sea experience the same selective pressures! As a mode of evolution, natural selection works by weeding out those who are not as fit as others, while promoting those who are most successful at survival and reproduction. If the history of evolution has taught us anything, it is that one important way to make sure your genes get passed on through your offspring is to become the best at adapting to your environment! A great example of such a concept is visualized in nine-spined sticklebacks (Pungitius pungitius), where the predatory avoidance behaviors of freshwater and marine populations provide insight into the differences in how they evolved this behavior from a common ancestor. Here, we summarize an article about these sticklebacks that was published recently in Evolution by researchers from the University of Helsinki.

A short podcast summarizing the article
Continue reading “Parallel Evolution of Avoidance Behaviors Exhibited by Freshwater and Marine Sticklebacks”

Adaptive Radiation and Three-spined Sticklebacks – Ecological Restraint Versus Opportunity

By: Emily Almeida, Caroline Houghton, Nathan Skopas, and Jada Thornton (Stonehill College, BIO323: Evolution, Spring 2023)

Three-spined Sticklebacks, Location of Study, and Introduction
The three-spined stickleback (Gasterosteus aculeatus) is a species of fish that can be found in temperate regions of the northern hemisphere and in seawater and freshwater habitats in the Atlantic and Pacific basins. Sticklebacks have long been considered a model organism for studying adaptive radiation, due to their parallel diversifications between freshwater sticklebacks and their marine ancestors. Adaptive radiation is defined as the rapid increase in the number of closely related species characterized by great ecological and morphological diversity. The driving force behind adaptive radiation is an organism’s adaption to a new environment. In this article from Ecology and Evolution, the population of three-spined stickleback fish studied were native to two Scottish islands, North and South Uist. Specifically, the diversity in the number and type of bony armor plates in species native to both islands were compared. Bony armor plates are structures on the fish that run along their backside and help to protect the fish from predators. Based on prior work, it was observed that the populations located on North Uist showed immense diversity, which was thought to be related to diversity of aquatic habitats within the area. On South Uist, evolutionary diversity within the stickleback population was significantly less, despite similar levels of diversity within the surrounding habitats. The diversity in pH on North Uist, and lack thereof on South Uist, has likely led to this drastic difference.

A short podcast summarizing the article
Continue reading “Adaptive Radiation and Three-spined Sticklebacks – Ecological Restraint Versus Opportunity”

The Cost of Reproductive Investment on Canine Life Span

By: Jentry Allen, Isabella Caldarone, Jacqueline Foley, and Nicole Godbout (Stonehill College, BIO323: Evolution, Spring 2023)

Dogs are said to be a man’s best friend as they are wonderful companions and can be trusted like no other pet; they are loyal to a fault. We find comfort in our dogs, maybe even purpose. Some people are willing to put their lives in the hands of dogs, allowing them to be their eyes, tell them if a food contains an allergy that may cost them their life, and inform a person if they are on the brink of an epileptic attack so that they may find a safe space and be prepared. An article from The American Naturalist titled, “High Investment in Reproduction is Associated with Reduced Life Span in Dogs”, discusses research on this ever-reliable friend and pet that shows a pattern in their life span in relation to offspring production. It was found that higher reproductive investment, or the work and energy that goes into reproduction, causes a decrease in canine life span. Additionally, it was discovered that this effect on life span was greater for larger dog breeds. With breeders today who want to breed more and larger puppies, we questioned the possible evolutionary effects of artificial selection, or the act of humans breeding animals to achieve a certain characteristic. If a breeder selects for a larger litter with larger puppies, the reproductive investment will be higher, and in theory, the life span of the mother will be decreased. Hear more about our discussion on this topic on the Everyday Evolution podcast!

A short podcast summarizing the article
Continue reading “The Cost of Reproductive Investment on Canine Life Span”

Why so Toxic: How Coloration and Toxicity Evolve

By: Hailee Arena, Caitlin Swanson, Elizabeth Cravinho, and Matthew Healy (Stonehill College, BIO323: Evolution, Spring 2023)

Just like your ex, being toxic is not always obvious! Did you know that frogs can display warning signals that indicate their toxicity, known as aposematism? Aposematism is a strategy employed by organisms to advertise toxicity to deter predators through color patterns. While this is a common trait, conspicuous coloration does not always signal toxicity. What causes coloration to evolve? Can toxicity depend on other factors, such as body size or time of activity? Due to this knowledge gap between conspicuousness and toxicity, Drs. Roberts, Stuart-Fox, and Medina, from the University of Melbourne, conducted research titled, The evolution of conspicuousness in frogs: When to signal toxicity?, as published in the Journal of Evolutionary Biology. The researchers collected data on various frog species to determine whether toxicity is linked to coloration. They examined the chemical defenses in these species and sought to identify whether body size and daytime (diurnal) activity could be linked to conspicuousness in chemically defended frogs. Ultimately, the researchers hypothesized that the conspicuous coloration in diurnal species is directly related to toxicity.

A short podcast summarizing the article
Continue reading “Why so Toxic: How Coloration and Toxicity Evolve”

Teenage Mutant Ninja Frogs! The Long-term Effect of Radiation on Chernobyl Tree Frogs

By: Stephen Cobbs, John de Abreu, Clare Feeman, and Molly Turner (Stonehill College, BIO323: Evolution, Spring 2022)

On April 26, 1986, the world effectively changed in the blink of an eye. An accident during a technical test at the Chernobyl Nuclear Power Plant near the city of Slavutych, Ukraine, produced what would eventually be referred to as “the worst nuclear disaster in history”. The consensus on the immediate, short-term effect of the accident was undeniably poor, as all wildlife within the area suffered mass casualties. 36 years later however, and the consensus is rather murky. Scientists have recently visited the Chernobyl Exclusion Zone (CEZ) and were shocked to find that area today presents great biodiversity, playing host to a multitude of different species from a multitude of different clades. Why is that you may ask? Well, some scientists believe that the radioactive pollution from the nuclear fallout led to an increase in mutation rates within genes of the animals in Chernobyl, which partially offset the diversity which was initially lost. This raises the question if there is such a thing as too many mutations and is there a line at which mutation rates cross from beneficial to deleterious? The paper Unusual evolution of tree frog populations in the Chernobyl exclusion zone, by Clément Car and 11 others, works to classify those questions, specifically looking at populations of Eastern Tree Frogs (Hyla orientalis) both in and around the CEZ and using simulations for populations throughout Europe as a whole.

A short podcast summarizing the article
Continue reading “Teenage Mutant Ninja Frogs! The Long-term Effect of Radiation on Chernobyl Tree Frogs”

Facultative Crypsis in Lizards

By: Patrick McLaughlin, Natasha Moniz, and Emma Tedeschi (Stonehill College, BIO323: Evolution, Spring 2022)

Crypsis, another term for camouflage, is a strategy that many organisms use to protect themselves from predators. Many organisms perform a process known as ‘environmental matching’, which is when an organism changes the color of their skin to match their habitat. Disruptive camouflage is a specialized type of camouflage that disrupts the organism’s outline by creating false edges, making it hard for the predator to find their prey. Studies have been conducted and results have been compiled into a scientific article called “Rapid Body Color Change Provides Lizards with Facultative Crypsis in the Eyes of their Avian Predators,” with research done by Kelly Lin Wuthrich, Amber Nagel, and Lindsey Swierk. This research has helped with understanding the ability of organisms to be able to rapidly change their body color and its effects on their survival. The experiments were conducted using receiver visual models, digital image analysis, and spectrophotometric tests. However, researchers have yet to reveal if rapid color change can alter the whole color of the body or patterns of an organism. When gathering research, many factors need to be taken into consideration, such as the predators’ visual systems, the rapidity of the color change, and the variety of microhabitats. Anolis lizards, or anoles, are known for their rapid color-changing abilities. Some species can change colors within minutes, going from light to dark and vice-versa. However, it has been discovered that going from dark to light seems to be more difficult for an organism than going from light to dark- it is more time-consuming. The researchers tested whether rapid body color change in water anoles (Anolis aquaticus) could provide benefits to the organism with proper camouflage between different microhabitats.

Listen now and read more below:

A short podcast summarizing the article
Continue reading “Facultative Crypsis in Lizards”