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: 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!
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.
By: Katelyn Foley, Eileen Mello, Erica Shepherd, and Joe Varney (Stonehill College, BIO323 Evolution, Spring 2018)
When a species extends across large geographic ranges, it is often found that the individual populations of the species differ physically and genetically from one another, as these subgroups are exposed to a wide range of environmental conditions within the range. Typically, populations found at the edges of the geographic range, or peripheral populations, are more likely to have adaptations or evidence of new traits as a result of their environment. One peripheral population of interest, the elephants of the Namib Desert, demonstrate unique behaviors and physical adaptations in comparison to other African savanna elephant populations. Knowing this, researchers from the Department of Animal Sciences at the University of Illinois were interested in how these elephants might differ genetically, as they show different behaviors compared to populations that are nearby.
