Evolution Blog

 Fitness and Survival An individual can have an absolute fitness higher than their relative fitness. This is because relative fitness compares the individual to the population's average and absolute fitness compares the individual to a perfect member. An individual who is different from the population could have a better chance of surviving and reproducing than an average member.  The first generation of individuals below have just moved to a new location. Where they are from they have tan, sandy beaches with clear water and plenty of places to hide. The new location is a bit less sunny, the beaches are less pristine, and have stones and debris with darker murkier water. Both individuals are successful and can reproduce with the lighter coat continuing with more success.  Over the next few generations, the darker offspring can go out during the not-so-sunny day allowing them to gather more resources to give them an edge. The darker water complements their darker coloratio...

  Survival of the Fittest  Good Enough In a previous post , we discussed how "Survival of the Fittest" doesn't exactly make sense. We also discussed that evolutionarily the word “fitness” relates to an organism's ability to reproduce and survive its environment. This leads to today’s topic of “Survival of the Good Enough.”  In survival of the good enough, we are looking for the individual who makes it through, not how well they did. This allows for the exploration of how little an individual needs to do to reproduce and therefore relative fitness. I feel this is a better explanation for evolution than survival of the fittest.  The full graphic from the video

Convergence, Natural Selection, and "Survival of the Fittest" What is convergent evolution? Convergent evolution is when species share a trait or character  not  from a common ancestor. In " Improbable Destinies " one of the convergent characters is the human eye versus the octopus eye.  If we look at the figure for convergent evolution, we can observe that the most recent common ancestor for humans and octopuses occurred many, many, years ago. This ancestor is known to not have eyes!  Octopuses and Humans have specially evolved photoreceptors that allow us to view the world more clearly.  When you look at scientific models of each eye you will notice they are almost identical! You can see from the above image, that several characters look and have the same function. The iris is in the same place, surrounding the lens, on both. There are specialized photoreceptors, nerve fibers, and an optic nerve for transmitting sight to the brain.  Eyes could have ...

 Mutation and the Tree of Life What is mutation and how does it affect the tree of life?  A mutation is a change in the genetic code that can lead to a change in a species. Every creature, big and small, has a genetic code that determines how they will look and survive in their environment. These mutations can also cause sicknesses such as cancer, leukemia, and Alzheimer's disease. A mutation that can affect evolution has to be able to pass from a parent to their child. Let's meet the Pacific Mouse (Pacificus rodentus)! These mice build homes on the sandy beaches of the island of Puuwai. They forage in the ocean for kelp to eat!  They have light brown fur on the top halves of their bodies and a light blue belly.  These characteristics allow the mouse to blend into the sand and  the ocean.  Let's explore some mutations in Pacificus rodentius! Looking at the family tree on the right, you will see that the first generation (indicated by "1") are all wild-type...