What is Fitness?


To me, fitness is a way to describe an animal's ability to survive and reproduce in an environment. How well it can obtain food, avoid predation, and contribute to its population's gene pool via reproduction.

To measure fitness in a natural population, you would have to take into account the main ideas listed above. Otherwise, you would just be looking at one aspect of fitness. For example, let's look at a white-tailed deer. You would have to measure what its nutrient intake should be, and estimate if the animal is receiving adequate amounts (it would be next to impossible to measure how much a wild animal eats, since you cannot weigh everything it will eat outside of captivity). If it is a dry summer, there might not be as much vegetation or water for the deer, and it can impact the fitness. You would also have to see how well it seems to avoid predation; animals with fur color mutations have a tougher time of doing this. Deer tend to be able to camouflage themselves pretty well in the wild, but if you have a rare case of albinism, the chances of that animal surviving decrease rapidly. You then also have to take into account how well it is able to reproduce. Sexual selection plays a large part in this for deer especially; the larger the male's antlers, the more likely he is to win in a fight with another male, and the more likely he is to mate with a female and pass down his genes. 


Comments

  1. Evolution: Haley JonesSeptember 15, 2021 at 7:01 PM

    Hi Katie,
    You bring up an interesting point about the diet and ability to find food impacting fitness. When you discuss measuring this, do you think that measuring the size of the deer would be a good indicator of its ability to find food? I also like how you bring up that random mutations can have a major effect on the survival capabilities, especially if it creates a large phenotypic change.

    ReplyDelete
  2. Shaun BaughmanSeptember 17, 2021 at 3:31 PM

    Hey Katie,
    I like how you brought up certain things within the white-tailed deer's environment. A dry summer is very possible, and this can effect the white-tailed deer in terms of the nutrients it is receiving. I think its easy to assume the largest organisms are the best fit, but the points you're making really assess why and what is affecting the organism to be this size. Great example!

    ReplyDelete
  3. Haley BurnsSeptember 18, 2021 at 8:42 PM

    Do you think variance affects fitness? How do you think animals would react to climate change revolving fitness?

    ReplyDelete

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