By: Ali Alsaadi, Colton Burkhart, and Alexio Trichilo (Stonehill College, BIO323: Evolution, Spring 2026)
A recent study published in Science Advances by Emmanuel Cazottes and colleagues reveals that one of the most important genes in the human body is XIST. It has kept its function over millions of years of evolution, but the way it is controlled has changed dramatically across primates. This research shows that evolution can reshape genetic “control systems” without disrupting essential biological processes, offering new insight into how genes evolve and why this matters for human health.
By: Haley Lussier, Madison Navega, and Madison Warren (Stonehill College, BIO323: Evolution, Spring 2025)
Did you know humans are most closely related to chimpanzees? Chimpanzees are remarkably diverse in their adaptation to different habitats, just like we are. Whether you are from Australia or the United States, your population can adapt to the habitat you are in. One cannot deny that change affects habitats, species, and the planet as a whole. Conservation biology has become a vital field for understanding and preserving biodiversity. One key concept in this field is local genetic adaptation, which ensures a species is well-suited to its environment and retains the potential to adapt over time. The recent Science article “Local genetic adaptation to habitat in wild chimpanzees,” by Dr. Harrison Ostridge and 73 coauthors, investigates the differences in the genetic makeup of wild chimpanzee populations to look for evidence that these differences provide an advantage in different environments. Dr. Ostridge completed this research as part of his Ph.D. dissertation at University College London, where he focused on population genomics and its relationship to disease adaptation.
By: Savannah Jeffrey, Julia Ciccolo, & Julia Bennett (Stonehill College, BIO323: Evolution, Spring 2025)
Overview: In many populations of cave-adapted animals, there is an increased presence of single-nucleotide premature termination codons, known as PTCs, that lead to traits losing function. PTCs are a type of mutation that cause a random stop to genetic replication processes, which can have deleterious effects on how traits are expressed. PTCs have been observed in the genetic makeup of many evolved cave species like cavefish, specifically the Mexican tetra, Astyanax mexicanus. Mexican tetras can be found in central and eastern Mexico, as well as in Texas. They originated in bodies of waters such as lakes and rivers, where eventually some Mexican tetras colonized cave systems and formed new populations. Due to these smaller population sizes in these environments, these mutations are subject to much stronger genetic drift, which occurs when alleles increase or decrease by chance in a population. This phenomenon causes traits to become more common or disappear entirely, thus making a population genetically distinct from their ancestors. Cave environments have their own unique selective pressures and allow the loss of traits to be advantageous for organisms, mainly features like eyesight, pigmentation, and circadian cycling. Allocating resources to these traits in an environment where they are not required provides no benefit to these organisms, therefore the loss of them actually positively impacts the species’ fitness, allowing them to invest in other metabolic processes. Additionally, the majority of PTCs arise in redundant genes, reducing the risk of losing genes that are vital for survival.
By: Rebecca Lancaster, Madilyn Robinson, and Savannah Ledo (Stonehill College, BIO323: Evolution, Spring 2025)
Overview
The Costus genus, commonly known as spiral gingers, is in the Costaceae family and is distinguished from other gingers by its unique spiraling leaves. Costus comprises over 80 species of perennial herbaceous plants native to Central and South America. Previous research demonstrates the Costus genus has independently evolved from the ancestral bee-pollination trait to hummingbird pollination multiple times. In The Convergent Evolution of Hummingbird Pollination Results in Repeated Floral Scent Loss Through Gene Downregulation, Dr. Kathy Darragh and her team examined over 30 Costus species’ floral scent compositions to understand how the species evolved from bee to hummingbird pollination. The study highlights the importance of selection, where certain traits are favored while others are lost to conserve energy costs. By comparing floral scent compounds, emission, and gene expression between bee-pollinated and hummingbird-pollinated Costus species, we gain a deeper understanding of the genetic factors driving floral scent evolution.
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.
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.
