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.

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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.

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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)

Overview
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!

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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.

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Bitterness on the Brain

Bitterness on the Brain

by: Alex Baryiames, Cassie Daisy, Mohini Patel & Olivia Peterson (Stonehill College Evolution Fall 2017)

Eating something bitter isn’t a great experience. The moment the taste hits your mouth can be an unpleasant one, and often causes you to avoid that particular food in the future. In an effort to understand this phenomenon, researchers discovered that the ability to detect these bitter tastes might have some evolutionary benefits! Read on to discover how the ability of vertebrates to detect bitter tastes can be a protective mechanism against toxic materials, and greatly contributes to our survival!  

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The Buzz about the Bees presents Fig and fig wasp coevolution

Fig and fig wasp coevolution

By: Caroline Colbert, Brianne Horton, and Brianna Salah (Stonehill College Evolution Fall 2017)

I’m sure you’re all familiar with the sweet and delicious taste of a Fig Newton, but did you know that the mutualistic relationship between fig plants and their pollinator wasps is to thank for this delicious snack. Also, did you know that this relationship is the result of millions of years of coevolution? Read on to learn more about this unique relationship!

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The Evolution of PMS

The Evolution of PMS

by: Lydia Blodgett, Alexandra Calafiore, Rachel O’Donnell (Stonehill College Evolution Fall 2017)

Premenstrual syndrome, commonly known as PMS, affects the majority of women and can cause an array of unwanted symptoms. Although up to 80% of women are affected by the symptoms of PMS, not much is known about exactly why it began and continues to happen in humans. Our podcast, “Evolution of PMS”, attempts to highlight the evolutionary basis of PMS. Using Michael Gillings’ article, “Were there evolutionary advantages to premenstrual syndrome?”, as a foundation, we explore the idea that the persistence of PMS is an outcome of its selective advantage to women. Although PMS has previously been considered maladaptive—with severe forms being classified as a diagnosable mental disorder—-Gillings proposes three main hypotheses that there are reproductive advantages for its persistence throughout evolutionary history.

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Why do birds get divorced?

Divorce in Savannah Sparrows of Kent Island

by: Michael Calcagno, Meghan Ghazal, Lizzie Poyant & Zarir Sidhwa (Stonehill College Evolution Fall 2017)

In Savannah sparrows (Passerculus sandwichensis) that reside on Kent Island, New Brunswick, Canada an understanding of divorce rates within the species was analyzed to determine the molecular basis of the phenotypic trait. As well as, to determine if divorce is an adaptive strategy for greater fitness for females. In this species, approximately 47% of pairs in which both partners survived to the following breeding season ended in divorce. Neither the lifetime number of divorces nor whether an individual had ever divorced affected the fitness of either sex, thus suggesting little to no sexual selection for the trait. Divorce in the Savannah sparrows appeared to be an inheritable behavior in which expression depending primarily upon an individual’s age, mating status, sex, and size.

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Dad’s social status effects offspring personality in zebrafish

Dad’s social status effects offspring personality in zebrafish

By: Colleen O’Donnell, Lauren Smith, and Courtney Walsh (Stonehill College Evolution Fall 2017)

Ever wonder if fish have personality? If fish have a social hierarchy?

Well, news flash, they do! Dr. Susanne Zajitschek had the opportunity to study Zebrafish, otherwise known as Dario reno, and manipulate their social hierarchy in order to determine whether or not this would affect the offspring of the Zebrafish. She focused on the paternal aspect of rearing offspring. Dr. Zajitshek combined this manipulation with the genetic onset of personality traits of the fathers. As a result of her research, she was able to find that both social status and personality traits do in fact affect the behavior of the offspring.

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This time Batman needs help … with whitenose syndrome

This time Batman needs help … with whitenose syndrome

by: Junior Andrade, Azariah Boyd, Kasey Dietzman, Zachary Fanara (Stonehill College Evolution Fall 2017)

Many people forget that bats are not just there for inspiring big-name superheroes. Bats play a critical role in pollination of many commercial products throughout the world such as bananas and peaches just to name a few. Bats also play an essential role in crop growth by maintaining the populations of common pests. However, bats in North America are in a time of crisis and it all began with fungus. Pseudogymnoascus destructans (P. destructans), a cold loving fungus, is able to grow in hibernating bats when their bodies reach a temperature of 39 to 68 degrees. This fungus grows and makes the bats ill and spiked a recent decline in North American bats. The disease was named White-nose syndrome due to the fungal growth resulting in white substance on the muzzle of the bats. White-nose syndrome has specifically hurt the North American little brown myotis bat which has been driven to the endangered species list in under ten years due to the syndrome.

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