Evolution Final Episode: The Evolutionary Forces Awakens

 Whew!

We made it through the semester (kinda)!🎉

And in remembrance and celebration of our time in Evolution class, I would like to reflect on ways I may have shifted in relation to my evolutionary perceptions.

To begin, one thing I realized was how connected the sciences are. For example, in this class we analyzed everything from the smallest genomic variation to the speciation of new organisms, and they all connected to other sciences like genetics or paleontology!

Another thing that I have really learned in this course is the COVID information helped with some comparisons of scientific data. Especially in a time where non-scientists are mis-interpreting data and then spreading that misinformation, it's good to know where the misconceptions came from and how they are debunked. Now, I know a little more about the origins of COVID, how the variants can emerge, and what we can do to counter act in response.

Lastly, I have noticed that I am really bad about anything computer-ish. Reading the graphs in the R exercises were very simplistic to me, but coding for it was SUPER difficult for me to understand. Although I struggled in that one area, I did enjoy the format of this class. Even though we didn't have any exams, I probably retained more information in this class than I did in any of my other classes. I think it was mainly because for the other classes I only wanted to learn information for the tests, but for this class it was so I could understand and interpret data correlated with the material.

Overall, I have enjoyed my time in this class and discussing with my peers on not only the material for evolution, but also bonding with everyday life. Oh, what a wonderful semester it has been, and good luck to all on their endeavors! Happy Holidays!!

Evolution Episode XII: The Rise of Lifestyle Disease

    As modernization of civilization has occurred, diseases that did not exist before seem to be appearing. One of those diseases of civilization include an increase prevalence of diabetes. There are different types of diabetes, but the generalized issue resides in the production or response to insulin which results in unregulated blood glucose levels. According to the University of California, Berkeley, this epidemic is due to the Western lifestyle of eating unhealthy foods, less activity, and longer lives (para. 1). This indicates our struggle in evolution between what our ancestors used to survive and passing down those genes and then our modern culture completely switching the gears on what we need to do in order to survive. Essentially, our daily lives contradict the genes from our predecessors. Then comes the question: How did this happen?

    As with many diseases, the simple answer is genetics. The Berkeley article illustrated by tracking the gene that encodes for diabetes risk, which is hypothesized to start in the Neanderthal lineage and then was introduced to the human population through inbreeding in Europe and Middle East (para. 6). To better visualize this, there is a diagram below.

Image Source: https://evolution.berkeley.edu/evo-news/the-deep-roots-of-diabetes/

    However, this data doesn't necessarily mean that Neanderthals had diabetes, it is more of a discrepancy between the genes and lifestyle (Berkeley, para. 9). Although we have hypothesized on the origin of diabetes, we still have not explored as to why diabetes could have evolved. In as study analyzed by Stanford University School of Medicine, they looked into evolution and the increase risk in type-1 diabetes. In the study, they believe that the development of diabetes could have an advantage in protecting against viruses and bacteria (Stanford, para. 3). There are more specifics to be discovered, but as to the why on inheritance of these disease causing genes we may have lead. Overall, diabetes is a complicated epidemic that impacts millions of individuals, but has only emerged in modern times due to the mismatch of lifestyle and genetics.

Sources:

https://evolution.berkeley.edu/evo-news/the-deep-roots-of-diabetes/

https://med.stanford.edu/news/all-news/2010/08/evolution-may-have-pushed-humans-toward-greater-risk-for-type-1-diabetes-study-shows.html

Evolution Episode XI: A New Species

   
    Hybridization can occur when sets of different alleles from a similar genetic basis are combined by sexual reproduction to produce a genetically combined individual. The process of hybridization can occur usually after populations who used to be allopatric re-meet and reproduce. This hybridization could end in several ways. First, the hybrid could gain an advantageous niche either physically or behaviorally which would help with survival rates an could ultimately create another new species. Another outcome could be the hybrid have a disadvantage reproductively being so different from the others in its area that it is no longer able to bear offspring.

    Although these outcomes directly oppose each other, they are important in analyzing how hybridization may impact biodiversity. If considering the first possibility of an advantageous hybrid, it could increase or decrease biodiversity. An increase may come as the new species is given an opportunity to evolve in specific directions that the other species that they derived from. The new species may be forced to try difference resources or times of breeding due to barely not fitting in with either the maternal or paternal sides. A decrease in biodiversity may come from a successful hybrid because it could merge two previously unique species. With the second, a decrease in fitness of the hybrid population may reinforce reproductive isolation between the two species. If an individual knows that mating with the other kind will not create successful offspring that won't live long enough to pass on their traits, it wouldn't make any sense to try and the waste energy; therefore, decreasing the biodiversity. Overall, it seems that hybridization does have the ability to increase biodiversity but is more likely to decrease it.

 

Sources:

https://revchilhistnat.biomedcentral.com/articles/10.1186/s40693-014-0016-0

Evolution Episode X: The Pipefish Menace

 

*This is not a pipefish. Just a funny picture of a fish. Do not be deceived*

    The Microphis deocata which is a type of pipefish is a special case when it comes to their dimorphism between sexes. In this case, the females have the colorful and dramatic features while the males have the more plain and basic characteristics. In most other species, the opposite is true and the males are more extravagant than the females. Pipefish are unique in this way because the females are actually courting the males rather than the usual other way.

    Since this is against the norm, one may question how this could be possible? I believe this occurs due to the male's ability to get pregnant. Considering that males are the ones getting pregnant, they are the one who have a longer time to invest and contribute to the reproduction process compared to the female. Therefore, the males can be picky on who they mate with because they need to know what they are investing into. In response to this, the females have developed pronounced characteristics in shape and color to attract males for mating. The main driver of this sex role reversal is the male's limitation of investment. Overall, the Microphis deocata are a fascinating species that have developed characteristics which are usually contrary to the rest of nature's approach to sexual dimorphism. 

Evolution Episode VIII: Return of the Genetic Variation

Genetic variation is sometimes thought to be eliminated as selection occurs through generation. From this approach, one would assume that as more generations accrue and the species become better adapted, which then causes the species in that environment have the same traits and genomic coding. So the question remains, why is genetic variation not eroded over time?

One reason that genetic variation is not depleted is due to changing in environments. As we know with the ever increasing climate change, habitats and environments are changing yearly. With this change, an adaptation that may have been advantageous before may no longer be. Therefore, the offspring will not be as successful as they might have be 5 years previously.

Other causes that maintain genetic variation include evolutionary forces that are not natural selection. For example, migration of populations can introduce new alleles from another environment. A force that can also influence would be gene drift. Additionally, the force of mutation is a HUGE factor as to why diversity still remains. Mutations don't necessarily have to have negative or positive effects, they can be neutral. These neutral, yet heritable changes in the genome, can be effective in later generations. You could say the randomness of mutation likes to keep things spicy.

Generally speaking, this assumption of selection reducing population variation means that there is A) An ideal form of the species that this selection is working towards and B)That we live in a tube. To disprove A, there is no "best" species or else all animals in a habitat would look the same. But once all of the animals have the same niche, it is longer good to keep that trait since it would have the animals competing for the same resources. As for B, we don't live in a tube? Overall, genetic variation is important for reducing inbreeding and a species surviving through this crazy changing world.

Evolution Episode VII: Ohhhh, We're Halfway There, Woah, Living On A Prayer

Halfway through the semester!! I know I am not alone in saying that it getting to that point in the semester where everyone is just exhausted. However, this exhaustion is not in vain for I've learned some things from my classes. One thing from Evolution that I have learned and has stuck with me is the meaning behind the Hardy-Weinberg Equation. I vividly remember going over the equation in BIOL 198 and thinking, "Okay I understand the math and that its for evolution, but where do I go from there?" Then, evolution class helped me realized it's more about a theorized relationship of allele expression and that the Hardy-Weinberg equilibrium isn't supposed to stand alone and should be compared to real life frequencies. When comparing to those wild population frequencies to the theoretical frequencies you can tell if an evolutionary force is present in that population. From determining if an evolutionary force is present, one can begin to look into which evolutionary force(s) could be possible.

In my original definition of evolution, I said, "The modification of a population's genome across descending generations." After learning more in class, I would like to make a couple of modifications to my definition. I would also like to add in the concept of evolutionary forces that may be influencing the modification such as migration, mutation, genetic drift, and non-random mating. I think this is important because my past definition makes it seem like the population acts independently in it's changes, but in reality there are a lot factors going into why evolution happens. My updated definition is, "The modification of a population's genome across descending generations driven by both external and internal forces with said population."

In area's that I am struggling with, I honestly had no idea what was happening with the last R exercise about COVID-19. At first I was excited to learn more about evolution affecting human health, but I just did not understand the graphs very well and their significance.

Since we have cover most of the evolutionary basics, I would like to better understand what evolution looks like for humans. Are there isolated populations with unique features that help them in their natural environment? Has technology contributed to any evolution in humans? Lastly, are there any connections in cancer and evolution?

Happy Halfway Everyone!

Evolution Episode VI: Populations and Inbreeding

Inbreeding usually has a negative connotation, but there are benefits and costs that come with inbreeding. When thinking about inbreeding, I am referring the mating of closely related individuals. One advantage to inbreeding it the ability to fix a desired trait to offspring. For example, breeding two dogs with the same genes for golden fur means the likelihood of their offspring having a golden fur phenotype is increased. Other traits, like amount of milk produced or muscle mass can also be selected for with inbreeding. This homogenization of genetic traits in a population can also be used for traits that may have not otherwise been present due to how recessive a trait is.

However, the appearance of a recessive phenotype can be a bad result as well. For example, many genetic diseases and defects accompany inbreeding due to their recessive qualities. One historical example of this is from the Russian Romanov royal family and the prince Alexei Nikolaevich who had hemophilia which is believed to have derived from royals trying to maintain bloodlines. Inbreeding can also conclude in recessive factors such as stunted growth, lower conception and live birth rates, and decreased cognitive abilities.

Overall, inbreeding (not unlike evolution) has many options on what can go wrong and what can go right.

Resources:

https://en.wikipedia.org/wiki/Alexei_Nikolaevich,_Tsarevich_of_Russia#Hemophilia

Evolution Episode IV: Revenge of DNA Polymerase

When thinking about how molecular processes relate to evolution, we must also relate to Darwin's postulates. These include:

    I. Individuals in population vary in traits

    II. Some trait variation is heritable

    III. More offspring are produced in every generation than can possible survive

    IV. Successful survival and reproduction of offspring is not random but dependent on the most    favorable variation

Genetic processes such a transcription and translation can be connected to the four postulates by noticing that genetic code is passed down from parent to offspring making it heritable. Also, individuals usually have unique DNA making the population vary in traits, which correlates with the first postulate.

Now that there is a link between evolution of traits and molecular processes, one can continue to ask, do mutation rates evolve? Yes, rates do evolve depending on the environment and demands. One driving aspect of this is the inheriting of the code for DNA polymerase. The one of the most common ways that errors in the DNA replication or transcription occur due to errors or variants of DNA polymerase. In saying so, if a parent has a mutation in DNA polymerase, the offspring is likely to inherit it as well which will create even more mutations elsewhere.

High mutation rates can be adaptive for cases like the inheritance of DNA polymerase because if the mutation rate it higher, there are more chances for offspring to have multiple variants which can survive. This would be ideal in a situation where the environment that is rapidly changing. On the other hand, low mutation rates may be advantageous for location with a less varied environment or where resources are constrained. If resources are constrained, it may be helpful to have a slower and more accurate DNA polymerase to make sure the few offspring to be produced have a chance to survive.

Before you leave, here's one last meme for you! :)

Evolution Episode III: Harder, Faster, Better, Stronger

Depending on who you're talking to, fitness can mean a plethora of things. Before thinking more about evolution, I thought fitness would be to make the species "better". From that stand point, one could ask, "what is better?"; so my definition had to be altered.

My definition for evolutionary fitness would be the ability to survive and pass on heritable traits through reproduction.

Although this definition seems straight forward, the measurement of this process is far from such. If I were to measure fitness in a natural population, I would approach it by counting the survival of offspring and the correlating parents. For example, if I wanted to quantify the fitness of mice, I would attempt to track the population's number of viable offspring that each female would have while also recording how long each parent/offspring would live. From there, the populations of mice that would live the longest and produce the most similar offspring would be deemed more "fit" compared to the other mice. The hardest part of this process is to tag and keep track of a sample population and also to know exactly how long each individual would live.

In the end, there is no perfect way to measure fitness, but as scientists, we can try the best we can and go from there. Also, the Daft Punk song that I reference in the title of this blog has a legit trap remix if you're bored and want to listen?

Fin.

Evolution Episode II: Microevolution and Eyes

Darwin had 5 predictions in relation to his idea of descent with modification. In this post, I hope to explore and mention some evidence that supports his prediction that species change through time (also known as microevolution). Microevolution is characterized by a change in the frequency of traits to be passed down to following generations in a population within a short time. To support this idea, I will be continuing with a study about a freshwater crustacean known as the Daphnia obtusa.

Pictured: Daphnia obtusa , dense black dot is the large eye https://www.eurekalert.org/multimedia/618756

Published from the University of South Carolina on November 20th, 2015, the study explored if a larger eye size and reproduction were linked. An overview of the article can be found from EurekAlert! here . In summary, the study found that there was statistically significant evidence showing that larger eye size is correlated with about one more egg created than usual. With this study, their goal was to find more subtle differences in ocular evolutionary changes compared to the more macro example of cave fish, which they achieved. Connecting the study with microevolution, the Daphnia obtusa with larger eye size were able to pass down the trait of having a large eye compared to having a small eye because they were able to produce more descendants. And this is only one example on how microevolution works, so there are still more to be discovered and researched!

Evolution Episode I: A Definition

The modification of a population's genome across descending generations.

Evolution is both fact and theory. To explain, it is a theory that is supported by data that explains the process of evolution. The reason it is a theory is that it has not been 100% completely figured out. Evolution is still being figured out and has many specifics yet to be discovered, which explains why it is partially fact.

Evolution: A Prologue

Oh hi, 

My name is Bridgett Winzer and I am originally from Augusta, KS. After my time at K-State I hope to go to either Portland, OR or Memphis, TN for optometry school.

Things that I am passionate about include learning, sloths, my faith, and all things eyes! Did you know that sloths can SWIM?! See for yourself https://www.youtube.com/watch?v=T7HGSvczDA4. Anyway, biology is an ongoing pursuit, but I am constantly in awe about how many things that are required just to live. Be it the specific jobs of organelles and the biochemical processes that must occur, or the cooperation of organs within a human being, the intricacies of biology continues to amaze.

One way evolution can relate to my daily life is that the bacteria from everything I touch can adapt with every generation. This is especially important to remember in the medical field due to the growing antibiotic resistance from microbes.

I hope that coming out of this class, I will have an educated stance on evolution and maybe even learn a little about coding?

Fin.