Skip to main content

Blog 3: Fitness

 Fitness is measured on an individual level and is NOT necessarily a measure of strength or power. Rather, fitness is how evolutionary biologists quantify an individual's reproductive success based on the relative contribution of their particular phenotype to the next generation's gene pool. Fitness can be absolute or relative, direct or indirect. Absolute fitness can be quantified as the number of successful offspring an individual produces in its lifetime. Relative fitness compares this number to the number of offspring produced by individuals of other phenotypes. 

For this blog, I was wondering how one would measure fitness of individuals in species that are cooperative breeders, such as meerkats. In meerkat society, there is a dominant female and male pair that does most of the breeding for the group. Other members help raise these offspring even though they are not their own. So how is this beneficial to them and how to measure fitness? This is where direct vs. indirect fitness comes in. Direct fitness measures an individual's production of direct descendants while indirect fitness measures production of offspring that are not direct descendants but are still related. Because they are related, the offspring still share some genetic material with their non-parent caregivers, therefore passing on that phenotype. So fitness of non-dominant meerkats is measured as indirect fitness - how much of their phenotype is contributed to their non-offspring kin. To compare fitness of dominant individuals, we can measure their lifetime reproductive success, which is the number of young they produce in their lifetime that survive to independence. Cooperative breeding behavior in meerkats increases the chance of survival of young since with more members of the family they can work together to guard and feed young more effectively than lone parents could. 



Sources:

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3856740/

https://www.pbs.org/wnet/nature/blog/meerkat-fact-sheet/

https://www.biologyonline.com/dictionary/relative-fitness

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3982663/

Comments

Post a Comment

Popular posts from this blog

Blog 1: Introduction

 My name is Victoria Gaa. I am most recently from Kansas, but it's hard to say where I am really from since I have lived in several different places before that (my favorite was Colorado). In the future I hope to go to a place where I can be happy, preferably somewhere with good friends, good job opportunities in wildlife biology, and surrounded by lots of nature. Being outside and enjoying the world around me is one of my major passions, whether that's reading under a shady tree in the park or hiking up a trail in the mountains. I also love the tallgrass prairie and am passionate about conserving this disappearing and beautiful ecosystem for future generations.  Evolution is so fascinating to me even before taking this class because it's wild to think about how life on Earth has changed and expanded from the first cell to the amazing biodiversity we see today. Every branch on the tree of life is a story evolution can tell us, from flowering plants to big cats to deep sea l...
3 comments
Read more

Blog 10: Reflection

 In this course I learned that the study of evolution is so much more than just Darwin's theory. I got to go more in depth about the different mechanisms and processes of evolution, and the different predictions and information we can take away from what we know about evolution. I loved the case studies that demonstrated actual studies related to what we were learning about in lecture and the textbook and getting to work through them in R. Speaking of the textbook, I thought it was great! The organization was fantastic and it was so nice to have one resource to go to both for help in R and to review the class material. It was super easy to use and just a great tool overall. To be honest, I was really dreading having to do coding in this class. I feel like I am not that great with computers and I had zero coding experience. But I actually found I kind of enjoyed it! While sometimes it was frustrating if my code wasn't working or I didn't understand something, it was rewardin...
Post a Comment
Read more

Blog 4: Mutation

 Mutations - any change in DNA sequence - are the ultimate source of genetic variation and therefore the base material for evolution. There are many different types of mutations, all with varying effects on an individuals fitness. Mutation rates are also important to consider.  Yes, mutation rates themselves can evolve to be higher or lower. Mutation rates can vary from individual to individual, and a higher or lower mutation rate may be beneficial or not based on the type of environment. This means that selection can act on mutation rates, which may lead to evolution. Mutation rates are heritable based on the ability of organism to replicate DNA sequences and repair mistakes, which is encoded in the genome.  High mutation rates would be beneficial in environments with high variation. If the environment is always changing, the ability of the populations that live there to adapt to varying conditions would be paramount. Adaptations arise from mutations, so the more amount ...
Post a Comment
Read more