Eliel Pepito
8/1/10
The Beak of the Finch Summary
The Beak of the Finch by Jonathan Weiner explores evolution through the most famous examples in history—the finches of the Galápagos Islands. Charles Darwin’s theory of natural selection and the process of evolution are applied directly to what scientists refer to as Darwin’s Finches. Weiner follows scientists Peter and Rosemary Grant as they study the finches in real time on the Galápagos. Years of previous work, study and data is collected and analyzed. Different species of animals are observed and explained throughout history. The Grants have one goal, and that is to find the origin of the species, how organisms first began. They find that it really is about the “survival of the
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The Grants observed how the two ground finches preformed while attempting to obtain a seed called a Caltrop. Caltrops naturally have spikes around the seed as a defense against intruders. The Magnirostris did not have a hard time cracking open the Caltrop, with its hard, powerful jaw. However the Fortis would have to put more effort into cracking a single seed. The regular Fortis would try for six times and then give up, moving on to another seed. They will often move onto a different seed without trying. However the Fortis with a beak that is slightly deeper beak would attempt to crack the caltrop, and after a few tries, will succeed. 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
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.
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
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.
On the 3rd experiment for Darwin Island, the independent variable was increased to 78.cm, while the independent variable for Wallace Island increased to 68. cm. The precipitation increase at Darwin and Wallace Island, indicated a decrease in beak size. The finch beak size in 2096, was measured at 10.72 mm. The decrease of the finch beaks at Wallace island measured at 11.61 mm. The population at Darwin Island increased to 682, while the finch population at Wallace Island increased to 660.
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
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
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.
In the sequel birdy is living his life back in the states. One main point of the story is him talking to uncle Richie and how the war effected him. The second main point is his life back In the states and living with all that he's seen. That last point is birdy living with his PTSD. the book starts off with birdy back in the states on the forth of July
On the Galápagos Islands off the coast near Ecuador we studied the behaviors of the animals, plants and environment on Daphne Major we found that the lack of rainfall during the wet season of 1977 caused most of the plants to produce less seeds and thus most of the medium ground finches died of starvation as their main food source had become scarce. Although the lack of seeds some finches were able to survive with their longer and bigger beaks. They were able to survive because their beaks were able to break open the harder and more plentiful Tribulus seeds that survived the dry season of 1977.
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
Darwin’s theory of evolution and natural selection came about when he visited the Galapagos Island and discovered that there were animals of all different types living there. While he was on the island, he seen a variety of Finches that contained a wide range of phenotypes which happened to be linked to their survival. On a certain part of the island he found a finche specie that adapted to their environment due to the absent of other species on the island. Therefore they learned to able to adapt to new niches. The food that they found required their beaks to gradually conform to the
- They are a married couple, British, evolutionary biologists at Princeton University. In 1973 they started to study the Darwin’s process in Darwin’s islands. They spent years focusing on Galapagos finches and observing the environmental changes and how these changes create certain individuals within the population (finches’ beaks).
This lab is designed to help understand how precipitation, variance, and area have a role in the evolution of a species, in this case, Finches. It also explains the different types of selection.
In the Galapagos Islands there is an island named, Daphne Major, this island plays as the host of the Galapagos finches. In 1976 - 1977 there was an absolute near extinction of these finches. This is because of the drought of 1976 and 1977 (see figure 1). While the drought made the Finch population dwindle there was a hidden trait that was helping some survive, and that is beak size. Why did the larger beaks help those fortunate Finches survive? Because the only plants that survived where plants like the Tribulus, which produces hard shelled seeds. While there was an abundance of hard shelled seeds there was a shortage of soft shelled seeds. The finches that had the larger beaks weighed more, for example, survivors weighed approx. 12.5g to 17.5g with beak sizes going from 10.5 to 13.6(for evidence see figure 2. This reduced the population because the Finch’s with the smaller beaks couldn't open the harder seeds and had to scavenge for soft seeds which were very rare. The finches with small beaks, then died from starvation
The Galapagos Island described as a volcanic archipelago in the Pacific Ocean it is a province of Ecuador found about 1,000km off its coast, and its considered one of the world's most supreme destination for a good view. Its secluded land shelters a variety of plant and animal species, many found nowhere else. Charles Darin took a visit in 1835, and his examination of Galapagos species later inspired his theory of evolution. He discovered that the animals would adapt to each of there environments no matter what the island was. On this trip to the islands there was two animals that stood out to him, and those were the finches and the tortoises. They all had similar characteristics but they were all on different islands.