Tag: evolution

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Rabbit and Hare Body Size Evolution

By: Meredith Kime, Courtney Marcos, Sean O’Leary, and Nick Scolaro (Stonehill College, BIO323: Evolution, Spring 2021)

Eastern cottontail: © Gareth Rasberry, shared under the CC BY-SA 3.0 license
Ungulates: © XAttlexattle, shared under the CC BY-SA 4.0 license

The rabbit, commonly known as a visitor in backyards, has evolved in a way to maintain a relatively small body size. In the Evolution article, “Why aren’t rabbits and hares larger?”, researchers Susumu Tomiya and Lauren Miller from UC-Berkeley sought to determine why rabbits and hares retained a small body size. Rabbits and hares are in the order Lagomorpha, along pikas. Compared to its sister clade, which includes rodents, rabbit body size evolution has been limited. This study does not include rabbits domestically bred, only wild populations of rabbits. Rabbits are an ideal group to study because of their limited diversity and extensive range across all continents, except for Antarctica.

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Projecting introgression from domestic cats into European wildcats in the Swiss Jura

By: Michael Piotte, Sylvia Mlynarski, Keith Francis, and Emily Yip (Stonehill College, BIO323: Evolution, Spring 2021)

© Michael Gäbler, cropped from the original, shared under the CC BY 3.0 license

Does this look like a normal pet cat to you? If so, keep reading; the true answer may surprise you.

When organisms reproduce, they randomly give half of their genetic information to their offspring. When two organisms from closely related species mate, the same process occurs. However, there is a significant issue. If this interbreeding between closely related species continues, it can lead to one or both species dying out. They will inevitably breed into one species, assuming they produce fertile offspring. This process is called hybridization, which can sometimes increase biodiversity by introducing a new species to the environment. This can also decrease biodiversity through changing environmental conditions and/or competition through a process known as introgression. This occurs when DNA from one species eventually swamps the genome of another species through interbreeding. Scientists from Switzerland and the U.K.  projected how this process might be affecting domestic cats and wildcats in the Jura Mountains of Switzerland.

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To Be Colorful, or Not to Be… There is no in-between!

By: Felicia Cafua, Maddie Fancher, Sydney Ledoux, and Deirdre Boyer (Stonehill College, BIO323: Evolution, Spring 2021)

One of the most exciting parts of life is the diversity of colors that animals exhibit. When looking at the diversity of an animal’s color, many questions arise: Why are there so many different colors? Wouldn’t this attract more predators? How do these different colors arise? Birds are a fantastic example of the diversity of coloration; even in one bird species, there can be considerable variation between individuals. Parrots, in particular, show a great diversity of coloration and can have very intense plumage coloration. Plumage color is the color of the feathers covering the entire bird collectively. The exact reasoning for such a wide range of plumage colors is not well understood. Here we summarize a recent paper on plumage coloration in parrots that was published in the Journal of Evolutionary Biology by researchers from the Max Planck Institute for Ornithology.

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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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These Spiders Can Jump and Dance, but Can They Use Their Moves to Impress the Ladies?

By: Stefan Balestra, Adam Casey, Alessandro Puccio, and Walker Smith (Stonehill College, BIO323 Evolution, Spring 2018)

Spiders are considered by some as a source of fear, but many people find arachnids to be a cool group of arthropods. I mean, one of the most beloved superheroes is Spiderman, after all. Adding to the coolness factor associated with spiders, the spider discussed below is not only a jumping spider, but also a dancing spider with an interesting ritualized dance used to attract a mate. Additionally, the male individuals of the species exist in two morphs with different ritualized dances, competing in a spider dance battle of sorts to impress the ladies. Read on to learn more about the specific mode of sexual selection that contributes to the male morphs’ different looks and dance styles.

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The Elephants of the Namib Desert

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.

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The Evolution of Nonbiting Mosquitoes

by: Marissa Beachell, Stephen Kulka, Mackenzie Lachkey, & Katherine O’Malley (Stonehill College, BIO 323 Evolution, Spring 2018)

There isn’t much worse than walking in after a night spent outside in the summertime and seeing your arms and legs covered in mosquito bites! While not every species or type of mosquito needs to bite to obtain food, many species do get their nutrients from a blood meal. What if there were a way that we could never get bitten by mosquitoes again but the mosquitoes actually live… and even thrive? We spend so much time and money on mosquito repellents and tiki torches that supposedly ward off these pests, while those in some other parts of the world set up mosquito nets to avoid a bite. It’s easy to brush off a few mosquito bites in Massachusetts or another urban area of the U.S., but for those countries with preventative mosquito nets, a bite could mean life or death. This whole landscape could be changing, however, as recent scientific research has illuminated a possible solution in which humans and mosquitoes both win.

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