Telomere Length and Life Spans in Starlings

By: Maggie Diehl, Michaela Duffy, and Bryanna Norden (Stonehill College, BIO323: Evolution, Spring 2019)

When we hear the word “aging”, the first images that pop into our minds are usually those of wrinkled skin and gray hair. Although these are common visual characteristics of aging in humans (and other animals), we often fail to recognize the biological processes behind these physical features. Just as our bodies grow old and lose efficiency, our cells lose their ability to grow and divide properly. The process of the gradual deterioration of function of cells is also known as senescence, which is currently a popular topic in evolutionary biology. For many years, scientists have proposed theories to explain the inevitable struggle of aging. Likewise, they have pondered whether conditions during early development play a role in the longevity of one’s life. To examine this possibility, researchers in previous studies have used telomere length as a predictor of survival. Simply put, telomeres are noncoding DNA regions on the ends of eukaryotic chromosomes. They serve as protectors, preventing unwanted deterioration or fusion with surrounding chromosomes. Additionally, they maintain chromosome stability and serve as “mitotic clocks”, shortening (in length) with each round of cell division. When telomeres shorten to almost nothing, coding DNA is exposed and damaged, resulting in cells failing to function properly. The rate at which these vital “chromosome caps” shorten may be accelerated by various environmental stressors in early life, leading to a faster accumulation of senescent cells (which cannot replicate) and an overall shorter lifespan.

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Are giant panda populations separated genetically across human disturbance features?

By: Liz Audie, Mike Lane, Samantha Morand, and Jackie Shuttleworth (Stonehill College, BIO323: Evolution, Spring 2019)

Ailuropoda melanoleuca, more commonly known as the giant panda, is facing serious population decline and is one of the many species conservationists are trying to save by protecting the areas where they live. While road development has been a huge advancement for us as humans, it has disrupted these pandas because it separates them from other pandas, causing subpopulations to form. This decreases the genetic diversity, which then reduces the probability that the given population will last. In the research done by Qiao et al. (2019), they chose to focus on the pandas from the Wolong Mountains. This region is heavily trafficked by tourists and is divided by a main highway (national road G350). Tourism is a possible threat to the giant panda population as it increases the isolation between pandas, and therefore the genetic composition.

Two captive giant pandas in Wolong
Figure 1 from Qiao et al.: “Two captive giant pandas in Wolong. Photo credit to Bo Luo of the China Conservation and Research Center for the Giant Panda.”

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Baboon Vocalizations and Primate Vocal Diversity

By: Fendy Lormine, Caroline Schad, Daniel Simosa, and Anna Walker  (Stonehill College, BIO323: Evolution, Spring 2019)

A remarkable trait unique to humans is spoken language; it allows us to communicate our thoughts, emotions, and intentions with other humans. While not as advanced as human speech, other species use different means of vocalizations to express themselves. Nonhuman primates have a largely genetically fixed acoustic structure that they use to communicate with each other. Their vocalization system is mainly comprised of grunts and loud calls. This study focused on the genus Papio as a model organism. More specifically, they studied chacma (Papio ursinus), olive (P. anubis), and Guinea (P. papio) baboons. The aim of this research was to see how the variation in vocal repertoire and call structure relates to social system characteristics. They focused on how the baboons interact socially and how competition among males and females is affected by sexual selection. The researchers hypothesized that loud calls would differ more between species than grunts. They also predicted that sexual selection would lead to more pronounced differences between males of different species than between females.

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Baboon Comparative Genomics

By: Zachary Frament, Frederick Kalisz, Griffin Lyons, and Alexia Zambarano (Stonehill College, BIO323: Evolution, Spring 2019)

In this article, researchers wanted to conduct an extensive analysis of the evolutionary history of the genus Papio, the baboons, and its six species. The researchers wanted to explore the genetic relationships among the six extant species: Olive baboon (P. anubis), Yellow baboon (P. cynocephalus), Kinda baboon (P. kindae), Hamadryas baboon (P. hamadryas), Chacma baboon (P. ursinus), and Guinea baboon (P. papio). Each of the species differs morphologically and behaviorally, and they occupy completely different geographical areas in Africa. Although the ranges that the six different species reside in do not overlap, researchers were able to find that the baboon lineages were experiencing hybridization and interbreeding in recent and past times. Some of the ranges are particularly close to each other, nearly overlapping, yet these six different species do not resemble each other morphologically or behaviorally.

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Evolution of High-Speed Throwing in Humans

By: Jason Comeau, John Jacques, and Elijah Morris (Stonehill College, BIO323 Evolution, Fall 2018)

Some primates throw objects occasionally, but only humans regularly throw projectiles with high speed and accuracy. Many scientists and anthropologists have been fascinated by the unique throwing abilities of humans. However, there has been little research into the evolution of throwing. Recent research completed at Harvard University has demonstrated several anatomical features that have evolved over time which enable humans to throw at high speeds. Human evolutionary biologist and anthropologist Doctor Neil Roach recently examined fossil records of early human ancestors and compared them to the modern day human.

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Lactase Persistance

By: Students (Stonehill College, BIO323 Evolution, Fall 2018)

It’s pretty possible that you or a few of your peers cannot digest lactose. You may cringe at the thought of eating dairy products. You may even notice that you or your friends get a stomach upset after eating treats like ice cream or have to take a pill before consuming dairy products. Have you ever wondered the biological reason for why some of us can digest lactose and why others cannot? As explained in the article, Impact of Selection and Demography on the Diffusion of Lactase Persistence, different genetic mutations give individuals the ability to digest lactose. Each mutation originates from different regions of the world. Due to lack of sunlight in northern European latitudes and high pastoralism levels in northern African latitudes, populations in these areas benefited most from mutations that allow individuals to digest lactose.

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Something you “MITE” not know

By: Jordan Callahan and Michelle Stracqualursi (Stonehill College, BIO323 Evolution, Fall 2018)

In nature, the male bulb mite is seen in two different forms. They could be a “Fighter” which means they have a thick third pair of legs with a sharp terminal, or they could be a “Scrambler” having thinner, female-like legs. Their morph is determined by an interaction between their genes and their environment. Environments with colder temperatures will have more fighter males, while a warmer environment will have more scrambler males. The temperature also influences the mites’ survival and reproductive success. Since the two morphs have different environmental preferences, they experience barriers to gene flow. Fitness is affected based on the phenotype that is expressed in each environment.

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Fishing through genes: the unique relationship between cavefish and Autism Spectrum Disorder

By: Matthew Mesiti, Trevor Tubbs, Nicholas Poli (Stonehill College, BIO323 Evolution, Fall 2018)

Today, autism spectrum disorder (ASD) affects a large portion of the world and is very prevalent in our lives. The well-known developmental disorder has been known to cause reduced social interaction, repetitive behavior, sleep deficits, hyperactivity, adherence to a particular stimulus, and higher anxiety level in humans. However, Mosato Yoshizawa and his research team discovered these same behaviors overlapping with Mexican teleost, a type of fish that is scientifically called Astyanaz mecixanus. More specifically, the research team found similarities in the genes of Astyanaz mecixanus cave-dwelling morphs and human ASD risk genes. Although the cave-dwelling fish did have a relationship with human ASD risk genes, the morphs also displayed positive selection and a positive response to human ASD drugs.

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Female Mating Preferences in Female Atlantic Mollies

By: Elizabeth Constantine, Mackenzie Gomes, Brianna Roy, Yasmine Sudhu (Stonehill College, BIO323 Evolution, Fall 2018)

In our own lives, we choose mates based on qualities that attract us. Typically, these traits are a mix of both physical and emotional characteristic, but regardless this preference is animalistic and instinctive. Fish, which are our distant relatives, exhibit similar mating strategies. In the Atlantic molly, female mollies choose to mate with males who are large in size, aggressive in nature and display a vibrant color pattern. The intensity of sexual selection is predator-induced. Female preference changes when predators are introduced into the equation. Seems hypocritical, until you see why.

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