Fitness (and maybe not the physical kind)

When humans consider fitness, we usually focus on strength, appearance, or stamina of a single person or type of person. In the world of evolution, fitness may be based on strength, appearance, or stamina, but it is not the same thing. Fitness in the natural world is the ability to remain alive and reproduce relative to other organisms. It may be a case where the fastest offspring gets the most food, the prettiest bird finds the most mates, or the organism best suited for the climate continues to live. One of the most interesting examples of relative fitness, in my opinion, is that of the kangaroo. Kangaroos are marsupials, which means part of the growth of a fetal kangaroo happens in the pouch on the outer side of the kangaroo rather than in the uterus. This means any potential kangaroos must crawl to a source of life within the mother kangaroo's pouch. Since kangaroos produce more fetal kangaroos than can fit in their pouches, a select number of fetal kangaroos make it to their mother's pouch, and those who do not make it are cleaned from their mother's fur and ingested. The trek from exiting the interior of the mother kangaroo to inside the mother's pouch ensures that the kangaroos who survive are the ones that are the strongest and the most compatible with survival. Mother kangaroos produce more offspring than can survive, creating a fitness relationship between those offspring.

Comments

  1. Jenna ThompsonSeptember 24, 2021 at 2:30 PM

    Wow, this is super fascinating and I had no idea that kangaroos did that with their offspring! I know that it's decently common in animals to eat their young if they think they are in danger or won't survive, but it's still such an odd concept since humans would never do that. I guess I also didn't realize that it could be such an uphill battle to get from kangaroo birth canal to pouch, sounds like it's their own personal Oregon Trail. Awesome post!

    ReplyDelete

Post a Comment

Popular posts from this blog

Evolution of Evolution: why have we not seen a big change?

When discussing evolution, there is usually a question of "when will it end?" or " why would anything still be evolving" or, better yet, "are humans evolving?" To answer these questions, we have to remember why anything ever evolves in the first place. Whether it be selection, nonrandom mating, or the weather, there is always a reason for evolution that is driven by some outside force. These outside forces are why organisms continue to evolve. We've had a heck of a time dealing with the evolution of COVID-19 over the past couple years! The reason organisms keep evolving is simple: to become better suited to their environments. It would not make sense for a bright pink moth to live in the dirt now would it? And to answer the question regarding the evolution of humanity, we have yet to see a true survival-driven evolutionary characteristic of humans in the modern era. Sure there may be redheads or blue-eyed people, but those mutations do not constitute e...
Read more

Evolution Pit Stop!

I have been learning so much about evolution and problem solving over these past few weeks. I have really enjoyed working my brain and making connections, asking questions, and solving problems that I don't normally get to see. My original thoughts on evolution haven't changed, per se, but they have grown. I understand more of the nitty gritty of evolution rather than just the general concept. I think I may still be struggling with some real-world applications of my knowledge, but some of what I have been working on has really helped drive that home. I am even more curious about how our general understanding of evolution as both a society and a scientific community will change in the future. I think more people are becoming comfortable with the idea that while we may not know everything about evolution we continue to learn more about it each and every day.
Read more

Piping the Pipefish

Much like humans, female pipefish are the more alluring and attractive of their species. This is in strict opposition to many other mating relationships in the animal kingdom. Why would this be? Maybe it's because there are fewer male pipefish and the females must fight over them. Maybe it's because male pipefish are picky and do not want to have ugly offspring. Even with all these different options for why female pipefish are the ornamented of a pipefish mating pair, one thing remains constant: the idea that females are more vibrant than males is evolutionary. Though conflicting theories of why these females may be more attractive exist, all theories are surrounded by the idea that the females must perform for the males and that the males prefer beautiful females. The females must appear attractive for a male pipefish to mate with them, and that is an element of sexual selection in pipefish. 
Read more