Survival of the Fittest?
Fitness is the ability to survive, reproduce, and pass off
your genetics to your offspring. The common saying “survival of the fittest”
gives off the wrong idea. Sometimes being the biggest or fastest is not what is
needed for survival in that environment. Instead of being big and fast, maybe
what’s needed in that environment to be considered “the fittest” is blending
into the environment or even providing the flashiest colorful displays in order
to reproduce.
For example, the hippo is considered fit for its environment
as it is huge and strong. However, what if the hippo was moved from the waters and
plains of Africa to the snow filled mountains? Obviously, the hippo is not fit for
that environment, it wouldn’t survive, it wouldn’t reproduce, thus it wouldn’t pass
on its traits to its offspring.
How would we measure fitness? Well, simply observe a species
and see how many offspring each individual has had along with measuring
survival rates among the adult individuals and offspring individuals.
Amphibians, like frogs, lay hundreds of eggs to maximize reproductive success as
the eggs have a high chance of dying or being eaten. Cheetahs on the other hand
only have a few offspring and low survival rate thus making their reproductive
success rather low. With there being a low population of Cheetahs, (they’re
going extinct) there is low variability in genetics and high instances of inbreeding
among the population. With all of these variables going against Cheetah’s their
fitness is actually rather low. Their fitness is especially low when you take
human interaction into account.
Here is a classic- Ice Age Survival of the Fittest


Hi there Haley,
ReplyDeleteI really liked what you said about how being the biggest or the fastest is not always the answer to being reproductively fit, I think this is an important distinction that people often mix up with what fitness "really" is. Also you're point about environmental dependency is something I didn't think of in regards to fitness. Meaning, there's probably a lot of thinking that some animals are more fit than others, period. But this can't be true because fitness, like a lot of life, is very dependent upon the context of you environment. Thanks for sharing!
Haley,
ReplyDeleteLoved your post, it was lots of fun to read! Your whole page is really cool too, I can tell you put in lots of effort creating it! Your example of the hippo being moved to a new environment illustrates fitness well and makes it easy to understand how it works. Fitness is always changing due to the many factors that play into environments and I think you explained that well.