Module 9: Favorite Trait

One trait that I have always found kind of cool is that of the skin of an African Spiny Mouse. These animals have very thin skin. Because of this, it heals faster than a normal mouse's skin. Specifically, two species native to East Africa, A. kempi and A. percivali, are able to get rid of unwanted skin when they are trying to escape capture from predators. Their wounds may look really bad at first, but within twenty four hours after the injury, the wound shrinks significantly. This is because their skin grows twice as fast as other wounds, (that are similar) in other mice. How cool is this! (Britannica) It would be interesting to see what exactly causes this, so we could see if somehow we could replicate this in humans. This would mean quicker healing skin injuries and a smaller chance of scarring. This is definitely something that would be intriguing to look in to!

(Here is a picture of some African Spiny Mice taken by Athanasia C Tzika, Univseriy of Kentucky, and University of Nairobi)

Anyways, the second part of the prompt for this blog post asks what adaptations there have been for this specific trait. After doing some research, I found the following information. According to Ashley Seifert, a developmental biologist at the University of Florida in Gainesville, she mentioned that it is rather unlikely that these mice's skin evolved a new way of regrowing tissue, but instead they probably have had genes that direct regeneration switched back on, (Nature). Ashley compared this gene regulation to salamanders, as I guess they have a similar mechanism! (Nature). Obviously, the mice would have had to evolve in order to get to the point where the gene was switched on. Since I could not find any information on this, I am unsure on how we could do this. Does anybody have any ideas? I also found that the fast skin regeneration could be caused by microphages that the mice have, (elifesciences). Which explanation do you think is the right one?  Or do you have another hypothesis? Additionally, do you think that studying these mice can help us find a way to help heal human injuries faster? I have listed my sources below so you can take a look at the information. 

Sources:

https://www.nature.com/articles/nature.2012.11488

https://www.britannica.com/animal/African-spiny-mouse (1)

https://elifesciences.org/articles/24623

Module 8: Genetic Variation

The prompt for this week asked why selection doesn't take out genetic variation. As we have learned from past modules in this class, there are many reasons why selection doesn't always have the final say. Factors such as migration, genetic drift, environmental factors, mutation, etc., are just a few of the diverse mechanisms that are able to explain why variation in genetics in populations stick around. As one can see, selection is not the only tool evolution uses.

Looking specifically at mutation and genetic drift, I believe these two mechanisms help the most when it comes to maintaining variation. They both happen randomly, which means the gene pool is ever changing. With mutations, it can be positive or negative, but regardless, it means that there is genetic variation in the population, as new genes are popping up in offspring. Additionally, some mutations can be neutral or silent. Selection usually is based off of traits you can see, (not always though), so it would be hard to get rid of these neutral mutations when selection can't pick off certain organisms based off of these mutations. Genetic drift also ensures variation by bringing in fresh genes from outside the population. 

Now that we know how variation still occurs even though selection is a thing, I think it is important to talk about why it is so important. If there was no genetic variation, (let's just say in a certain population), there would be a lot of inbreeding, which in turn can cause diseases and other developmental problems, (module 6 discussion talks all about this). Another reason why genetic variation is important is adaptability reasons. If a population all had the same genes, and some environmental crisis happened in their habitat, they would ALL die. If there was some variation, then there would be a likelihood that some might survive due to a genetic trait that they possess that might give them an advantage. For example, a drought happens. If there was a population of rats that was all white, then they would all be picked off. However, if the rat population had variation in fur colors, (let’s say brown and white), then the rats with the color that blends in with their environment would have a higher chance of surviving.

(Picture from https://www.domyown.com/all-about-rats-a-764.html)

Module 7: Quick Check-Up

Wow! We are half way through the semester already! I would say it has gone by slow, but that would be a lie. It's crazy how time flies. Hopefully the second half of the semester will go as well as the first half did.  When looking back over these past few weeks on what I have learned in this class, I have learned more than I would have originally thought, (I believed I would be really confused the entire time and not understand the material). 1. I am not a coder, nor will I ever claim to be. 2. However, coding isn't toooo terribly bad! Once you have a concept down, it gets easier to replicate it. 3. I understand the topic of evolution much better. 

When looking back at my first blog post, I defined evolution as occuring when an inheritable trait passes across generations. I also said that evolution could not happen to an individual, and that factors such as genetic drift, natural selection, and genetic mutation all can play a part in it. Now, with a better understanding of evolution, I would say that my definition was ok, but there could have been more added onto it. For example, evolution can differ on size (microevolution vs macroevolution), natural selection perhaps plays the biggest role in evolution, (this can be argued against), and that the rate of which an organism evolves really depends on its environment. Even though I feel like I have gained a greater understanding of evolution as a whole, there are still some topics that I struggle with. I mentioned above that I have problem with coding sometimes. I also have trouble with comprehending allele frequencies and what exactly they mean. This made interpreting the graphs on R especially hard for me personally, as it just seemed to look like a bunch of numbers.

Now that I have studied some of the basic concepts of evolution, I have had two questions pop up into my mind in class.

1. What would it take for evolution to be made  a fact and not just a well proven theory?

2. How could knowledge of evolution help us with a natural resources problem? I don't know if these two things even connect, but it would be cool if evolution could help out!

I look forward to perhaps getting to answer these questions! I have learned a ton in this class, and I hope to continue to do so. 

Module 5: Inbreeding

To understand the benefits and costs of inbreeding, I think that it is important to define the word. Inbreeding is, "the interbreeding of closely related individuals especially to preserve and fix desirable characters of and to eliminate unfavorable characters from a stock" (Merriam-Webster). So, basically, it is when a parent/offspring, brother/sister, and half/brother and sister copulate. First cousins and second cousins are considered inbreeding in humans, but in animals, people have a hard time drawing a line when it is considered inbreeding or outbreeding (Massey et. al). When looking at the given definition, you can begin to pull out the benefits of inbreeding. Preserving and zoning in on a specifically helpful trait can be very useful for an organism. Inbreeding also helps to get to the desired trait faster. Dogs are a common example of an animal that is interbreeded a lot. They make for cute animals, but a lot of these animals have health problems later on in life. 

Although there are some benefits of inbreeding, I believe the costs outweigh them. To demonstrate these, I picked the cow as my example, as most of us are affected by these animals. Inbreeding is actually allowed with these animals, but it is recommended that they should only share 6.25% of their genes with the other animal they are being bred with, (so, breeding with a cousin instead of an immediate family member). If the cows share any more genes, problems start arising including lower productivity, fertility problems, reduced longevity, and a higher frequency of hereditary abnormalities (LIC). Abnormalities occur when both of the parents have a recessive gene for this abnormality. Usually, having a recessive gene for abnormality isn't a big deal. The possibility of an organism breeding with someone else who has this exact gene is low. However, when an organism breeds with a close relative, the relative most likely has the recessive gene, which will then lead to problems in the offspring. 

If you look at this website that I attached below, you will get to read about some cool tools that this company uses to make sure that they are not inbreeding their cows too closely. Happy, healthy cows are better for everyone in the long run!

(https://www.lic.co.nz/products-and-services/artificial-breeding/inbreeding-and-recessive-genes/)

Sources:

LIC. “Inbreeding and Recessive Genes.” LIC, https://www.lic.co.nz/products-and-services/artificial-breeding/inbreeding-and-recessive-genes/. 

Massey et. al. “Inbreeding: Its Meaning, Uses and Effects on Farm Animals.” University of Missouri Extension, https://extension.missouri.edu/publications/g2911. 

Merriam-Webster. “Inbreeding.” Merriam-Webster, Merriam-Webster, https://www.merriam-webster.com/dictionary/inbreeding.