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.
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.
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!
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.