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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Surviving the winter: how two species of penguins have evolved to endure the harsh Antarctic climate

By: Heather Carson, Kaitlin Kotfila, Lauren Gillis & Sidney Sechio (Stonehill College, BIO323 Evolution, Fall 2018)

Penguins are unique, flightless aquatic birds that live primarily in the harsh conditions of the Antarctic. In a research article published by Cai Li et. al, the scientists discussed the adaptations of male emperor and Adelie penguins that allow them to survive such harsh habitats. These two species of penguins are very similar, with few slight differences. One similarity is that these penguins have evolved flipper-like wings that aid them in underwater flight. The researchers built a phylogeny to evaluate the similarities between the two penguin species. Some other adaptations they noticed that were similar between emperor and Adelie penguins were their unique feathers, visual sensitivity, and a thick epidermis. Penguins’ feathers are particularly useful to prevent heat loss; the researchers found that these two species have the most feather-associated proteins of all penguins. The major difference that the researchers found between emperor and Adelie penguins was their lipid metabolism ability. A gene involved in lipid metabolism has been selected for in Adelie penguins, but not in emperor penguins.

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Is anole evolution predictable?

By: Royce Conlin, Mark Khalil, Claire Manuszak, and Meredith Moore (Stonehill College, BIO323 Evolution, Spring 2018)

In this article, scientists examined various species of anoles. Anoles belong to what many know as the “New World” lizards, closely related to iguanas, and can interestingly change the color of their skin related to their environment.  Anoles generally thrive in warm, moist environments; in cooler weather, anoles tend to hide out and take shelter in a confined area. Most anoles live in the southeastern U.S. and the Caribbean. Many scientists have taken a strong interest in anoles due to their fascinating evolutionary histories.

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Snaking Around Evolution

By: Nia Campbell, Chris Driscoll, Ethan Fultz, and Rachael McCabe (Stonehill College, BIO323 Evolution, Spring 2018)

Regressive evolution is the process where a trait is lost or becomes dysfunctional in a species over generations. This type of evolution is the opposite of constructive evolution, where a species evolves a new or more complex structure. Regressive evolution is a difficult method to use to classify species into evolutionary lineages because it often can only be identified by finding a genetic trace, such as a mutated or deleted gene in the species’s genome. In a paper published by Christopher A. Emerling in 2017, three traits found in relatives of snakes were examined in snakes for evidence of regressive evolution: presence of claw keratin, taste receptors, and light-associated genes.

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Did a poor immune system contribute to Neanderthal extinction?

By: Kaili Jackson, Yash Malai, Nina Parziale, and Nick Perry (Stonehill College, BIO323 Evolution, Spring 2018)

Despite the many great technological and scientific advances that have defined the 21st century thus far, there are many important questions that remain unanswered. Among them is the ultimate reason that Neanderthals went extinct while humans were capable of further survival. There are several theories as to why this occurred, and scientists continue to debate which factors may have contributed to Neanderthal extinction to the greatest extent. Some examples of suggested theories include the possibility that climatic fluctuations may have had a negative impact on Neanderthals; the hypothesis that modern humans’ shorter gestation period allowed for more rapid population growth; and the proposition that the intelligence and language capabilities of modern humans were superior to Neanderthals, allowing them to develop better hunting strategies such as the domestication of dogs to aid them during large animal hunts. Another potential theory, which the article An evolutionary medicine perspective on Neandertal extinction presents research on, is that viral disease transmission from modern humans may have contributed to the ultimate extinction of Neanderthals. This research was led by Alexis Sullivan from the Department of Biology at Pennsylvania State University. This theory is known as the differential pathogen resistance model.

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