Shay Lukas
Link: http://www.sciencedaily.com/releases/2015/01/150109093727.htm
Author/Source: Monash University
Date: January 9, 2015
Summary:
This article pertains to observations of the Central American Freshwater fish. This species of fish has color variants, meaning some of the fish are one color and some are a different color. This puzzled researchers because according to the idea of natural selection, one color should be the acquired trait and become the norm of the population. Will Sowersby, the head researcher, had his team observe a specific type of fish: the red devil cichlid. They come two different colors; dark gray and gold. Sowersby and his team observed that the dark colored fish is more common throughout the species. They then discovered that this fish could change their coloring to better match their environment, making it the desired trait. Therefore the gold colored fish is more rare, even though it is genetically dominant. To test this further, the researchers filmed the fish over light and dark surfaces. They measured the change in the fish's body color. They discovered that the dark colored fish could actually alter its brightness to fit the specific background, while the gold fish was unable to do so. This suggests that how well the fish can blend in with its background impacts the evolution of the coloration of its species.
Connection: This article connects to what we have been learning about evolution in class. It discusses natural selection and acquired traits, which are two key terms in our studies. The darker colored fish possesses the acquired trait, and is more likely to survive then the gold colored fish. In the past, there were more gold colored fish because it is the dominant trait. Yet over time, natural selection has taken place, allowing only the strongest to survive. This made the gold fish much more rare, because it cannot hid itself as easily from predators. This relates to the idea of fitness, which is the contribution an individual makes to the gene pool of the next generation. This relies on an organism's ability to survive and produce fertile offspring. More dark colored fish are surviving and mating, while a lot of gold fish die before they reach that point. That makes the dark fish more fit then the gold fish, causing it to survive natural selection. Natural selection is still occurring in this species, and soon it will evolve into an entirely dark colored fish species. The different coloring of these fish also relates to the concept of biodiversity and genetic variation within a species.
What are risks of being a gold fish in this environment? Will they be killed, spotted easily? How come they are not able to adapt to the surrounding environment?
ReplyDeleteWould the allele for gold fish eventually be lost because of how many dark fish there will be in the future, or would the gold allele stay constant because it is dominant.
ReplyDeleteThe main risk for a gold fish in this environment is that they are easily found by their predators, and have no way to hide themselves. Therefore they are killed easily. The reason that they cannot adapt to the environment is because the coloration of their skin cant alter it's brightness (like the dark colored fish can). This means that they stay the same color/shade and do not blend in with the surroundings.
ReplyDeleteDue to natural selection, there will be a smaller and smaller allele frequency for the gold colored fish. But this process will be slowed since the allele is dominant, and it may not entirely be lost.
ReplyDelete