Evolution Lab: The Impact of Drought Conditions on a Finch's Beak Size

Some finches inherited longer beaks, this allowed them to open more seeds and access more food. Inheriting the longer beaks is not proven, but any animal inherited traits just like humans. So gathering this information we can conclude that they inherit their long beaks. Having a long beak was crucial in order for the finches to survive through the drought. Two finches, for example, that survived the drought, had bigger beak sizes. Gf69 had a beak length of 13.01 millimeters and weighed 13.41 grams. Another finch that survived the drought had a beak length of 10.97 and weighed about 12 grams. Yet a finch that didn’t survive had a beak length of 9.92 millimeters. All 10 finches that survived through the drought had longer beaks that averaged to 11.939 millimeters. This is a large beak size compared to a bird that did not survive with a beak length of 7.21 millimeters. A bigger beak length allows a finch to pry open harder seeds unlike the finches with smaller beaks. Some field notes were taken from the Grants, and they told us that a finch was spotted struggling to open a seed. For this reason finches with longer beaks were able to get food more easily than finches with smaller beaks. In conclusion, some finches had a longer lifespan than other for the reason that they had longer beaks. On top of that they were able to survive the

Assignments 1: I developed a hypothesis to predict that the island with the finches with the larger beak will be able to adapt more rapidly to their surrounding and handle the hard seeds of their island verses the island with the finches with the smaller beaks. I left the primary beak size on Darwin

Over the last several years, evolution has been playing an increasingly important role in determining how various species are evolving. This is because ecology will have an impact on how quickly a particular organism is able to adapt (with: the unique challenges for a particular environment). To determine the effect that this is having requires carefully examining different species over the course of many years. This will be accomplished by comparing these changes on Darwin and Wallace Islands. Once this occurs, is when specific insights will be provided that are highlighting the underlying challenges affecting the development of organisms. This is the point that these transformations will be evident among the various life forms. (Fasolo, 2011, pp. 53 68)

The Grant’s are capable of studying Darwin’s theory of natural selection in action, after gathering data from their colleagues, Peter Boag and Laurene Ratcliffe, who would be their watch on Daphne Island. Peter and Laurene witnessed an important event in natural selection, during a life or death situation with the finches. Though the two scientists were anxious for rain, but they did not receive a single drop that season. Rain would mean reproduction and fertility for the finches; however, the birds were faced with e horrible drought. Food became scarce and the finch population declined. Easy seeds to obtain on the ground were nearly gone. The seeds with tougher defenses, such as the caltrop, were usually untouched, since they were hard to crack. The finches with inadequate beaks did not

The Evolution Lab simulates environmental situations to determine effects on evolution over periods of time. This lab experiments with the evolution of finches on two different islands over 100, 200, and 300 years. By manipulating parameters that influence natural selection, the effects that natural selection have on the evolution process can be studied.

The Avis Papyrus, more commonly known as the Carmel Origami Bird, native to the sparsely spaced Cool Creek Islands, was subject to a study of its evolutionary success. These birds must travel long distances to get between the islands they inhabit in order to survive long enough to produce offspring; meaning that being able to fly long distances aids in their fitness. The development of these beneficial characteristics are possible because of something called natural selection. Natural selection is the gradual process over the course of generations where a species gradually develops and excludes traits and characteristics (Fukuyama, 2004). This is to help increase reproductive success of an organism and increase the animals fitness. The experiment looked at how natural selection led to their evolution and it’s raw data shows evidence that the Origami Birds have met evolutionary success due to natural selection.

One of its most important characteristics is its beak. The finch adapted to have a thin, long beak to probe through moss, bark and leaves in search of food (Wildscreen Arkive, N.D.). These finches have the thinnest beak out of the 13 finches; which aids them to find small insects. The Green Warbler finch are mostly found in humid highland forest where their primary food source is found. These adaptations made them more fit to survive on available food. Over the years the finch’s beak has evolved as the bird developed different taste for insects. Another famous adaptation is how they camouflage in their environment. The Green Warbler is restricted to the forest and is greener in body colouration, while the Gray Warbler is found in shrubby, dry thickets and is greyer and duller looking (Certhidea olivacea, 2010). Their coloration helps them camouflage in their own environments, and to hide from predators. Recent studies have found that there are in fact two separate species of the Warbler Finch, the Green Warbler Finch and the Grey Warbler Finch, but are considered as a single species (Wildscreen Arkive, N.D.). The Green Warbler finch mainly occupies larger, inner islands, while the Grey Warbler finch inhabits the smaller, outer islands (Green Warbler Finch,

In 1977 a drought reduced the number of small seeds available for the birds, forcing them to rely on larger seeds and nuts, which were difficult for birds with smaller beaks to open. The number of birds unable to eat reduced as they died and gave way to harder beaked finches. Within a couple of generations they had evolved larger beaks. In 2003 another drought struck the Galapagos and as there were many large beaked finches, the food source of nuts dwindled, making the ability to eat smaller seeds an asset. The numbers of larger beaked birds dwindled as food became scarce, leaving the smaller birds to survive and reproduce. Darwin’s theory was not well received when first written in On the Origin of Species, though many scientists today use it as a basis for research in evolution.

9. Precipitation plays an important role in the evolution of these finches. Low levels of precipitation results in plants that produce hard seeds. High levels of precipitation favor plants that produce smaller softer seeds. Medium levels of rain produce medium seeds. Click the New Expt button and then click the Change Inputs button. Click the Precipitation button. Notice the percentage distribution of hard seeds, medium seeds, and soft seeds as precipitation is changed. Finches with small beaks are better at utilizing soft seeds as a food source. Medium and hard seeds require larger beaks. Increase the annual precipitation on Darwin Island to 100.0 cm/year and Wallace Island to 10.0 cm/year. Now click on the Beak Size button and set the initial beak size on both islands to 20 mm. Click the Done button and Run Experiment button. Click the Beak Size tab and then the Population tab. Which of the following statements best describe what

Medium ground finches had small beaks before but changed over time. This was caused because of evolution and survival of the fittest. When Charles Darwin came onto the island he wondered why there were many different species of the finches, then he hypothesized that a group of finches might have came in from South America. Then splitting of the finches and adapting into their environment to have a better chance of surviving. The finches beaks helped with Darwin thinking

“If no such variations exist, the population rapidly goes extinct because it cannot adapt to a changing environment” (O’Neil, 1998-2013). Scientists call this reproductive success. “Within a specific environment context, one genotype will be better than another genotype in survival or reproduction for certain reasons having to do with the way its particular features relate to the environment or relate to other organisms within the population” (Futuyma, 2000-2014). The theory of evolution is explicable through various kinds of scientific research.

Evolution is the process of change in a given population. There are 2 possible ways this change can happen. One way is through the difference in abilities of individuals to survive and reproduce. These differences, or variation, are largely created by genetic mutations in the DNA, ultimately making each individual different from one another. This idea of variation can be shown in Figure 2, where even though they are all the same species in Daphne Major, Medium Ground Finches, they all have a variety of different Beak Depths. This difference among each Finches forces some to have a natural advantage while others to have a natural disadvantage, purely based on the environmental conditions. This is mainly because some traits are more well adapted

Some reasons why beaks were thought to be so useful for testing Darwin’s theory of natural selection was because it seemed that the more favorable variations in their beaks will be passed down. Another reason was because there were more variations in the beaks depending what the finches ate so he could study a variety of beaks.

When that happens over many generations a species’ gene pool changes to only include the traits that are a best fit for ensuring survival of that species, and a new species may evolve. In the case of the Galapagos finches Darwin studied, biologists have since found that one of the differences was their beak size, which were adapted to the specific seeds available to the finches as food on the different islands. This would support this principle as only the birds able to eat the local seeds would be able to survive to reproduce, thus over many generations, new finches with a variety of different beak sizes would “evolve”. The

Over time the beak would become longer and those birds would survive. The next mechanism, genetic drift, happens by chance. For example, a bug that is either red or green. If a large portion of the red bug happens to get stepped on, the gene frequency for this species is now changed. Mutation is another evolutionary mechanism that happens by chance. Mutation is when the genetic material of an organism is altered. An example of this is albinism which has altered the genes of several different animals.