Student Evolution Blog

 Absolute fitness and relative fitness are evolutionary terms used to describe an organism's ability to survive and reproduce. However, there are key details to these terms that make them different and can make a huge difference in an organism's fitness rating. Absolute fitness is the number of offspring an organism can reproduce that reach reproductive age. These offspring will contribute to the next gene pool, resulting in a continuation of the parent's genetics and increasing their fitness. However, relative fitness compares the absolute fitness of different organisms in a population, comparing the reproductive success of different genotypes.  The organisms in this example are dogs, but I am going to use names, so this example is easier to follow. For example, if Betty produces 10 offspring and 9 survive to reproductive age, she would be considered to have a high absolute fitness. However, if you compare Betty to Shanna, who is producing 20 offspring with 17 making it to...

 Most people have heard the term "survival of the fittest" in school when talking about evolution and natural selection. However, have you ever heard of the term "survival of the good enough". It is a concept in evolution that explains how organisms adapted to their environment, not in any extreme way, will most likely survive and reproduce more often, impacting evolutionary processes more than organisms with extreme phenotypes. For example, most people would think the biggest gorilla would be the most successful in natural selection because he is the most "fit". However, since he is the biggest gorilla, the other gorillas are constantly trying to take over as the biggest gorilla. This leads to him expending a lot of energy fighting for his spot and to keep his females from other males. Gorillas that are big enough to survive and reproduce, but are not the biggest in the area, will have a higher chance of passing on their genetics because they will have mo...

Convergent evolution is the independent evolution of unrelated species forming similar features or phenotypes. This can commonly be mistaken for divergent evolution, the process in which related species evolve different features or phenotypes, forming different species. An example of convergent evolution was discussed in chapter 1 of the book "Improbable Destinies", discussing the similarity in eyeballs between vertebrates and octopuses, an invertebrate. Their last common ancestor was roughly 550 million years ago, but their eyes are nearly identical! This convergent evolution occurred because both vertebrates and octopuses have the same genes to develop eyes from the common ancestor. Over time, after they split into different species, their environments caused an evolution of their phenotypes where individuals with good vision survive more than those with no vision. Because of this, both species developed the same phenotype for eyeballs, which look extremely similar because ...

  Mutation is an alteration in an organism's genetic makeup. This alteration can be caused by various reasons, including, but not limited to, environmental causes, chemical exposure, or natural occurrence during childhood development. For example, you can see in the illustration a tree of life of an organism in a population, called wagbot. All the wagbots in this area are gray because they have the highest survival rate with this fur color. However, one wagbot (Ⅱ-Ⅱ) experienced a mutation because his mother (Ⅰ-Ⅱ) did not receive enough nutrients while he was developing, causing him to be a shade of red at birth. We can tell this alteration was a mutation because his parents and siblings lack the genetic material to cause red fur.  This mutation can be neutral, beneficial, or harmful to the wagbots. For example, this mutation will be beneficial for the red wagbots if it increases their survival rates compared to the gray wagbots. With higher survival rates, the red wagbots will...