The Beak of the Finch
Here's my crappy Bio report on the beak of the finch Enjoy!
And sorry about that bad punctuation... and the lack of paragraphs it's too late at night to fix that.
Plus I'm too lazy. It's still readable.
The book The Beak of the Finch deals with natural selection in our time and how it connects with evolution. The majority of the book is set on the island, Daphne Major, in the Galapagos Islands. This is the chain of islands where Darwin first tripped upon his evolutionary theory. This book follows the 3 decades that Peter and Rosemary Grant have studied Daphne Major with the help of Princeton University.
Many people have a large misconception about evolutionary scientists. They do not realize that these scientists also do experimentation like other scientists. These experiments help to determine why evolution occurs, how it occurs, and when it occurs. This book is based on the research that proves and answers these questions.
There are thirteen different types of finches on the island. These are then divided into four categories: Tree Finches, Ground Finches, Warbler Finches, and Cactus Finches. The book bases its investigation around one group of finches, the ground finch. These are extremely peculiar birds because the only distinguishing characteristic separates the three different species -- magnirostris, fortis, and fuliginosa -- is their beak size.
There were many questions that puzzled the Grants. Why do the three groups of finches all have different beak sizes? Why not have one all-purpose beak size? Why are there three distinct groups of finches with only a few in between? Why aren't they all spaced evenly through out?
The isolated population of Daphne major was perfect to study evolution with. The population of the island finches could not move far from the island and throw off the data. Daphne major is approximately 35 miles away from the nearest island and has sloped sides that go straight up. Therefore, this is the place where the Grant's and their following do the majority of their watching. The temperature can reach 115 degrees and on the black hardened lava the heat can fry an egg literally.
The first major incident of natural selection taking place was the drought of 1977. After Peter Grant had invented a device to measure the newtons necessary for cracking certain seeds, which are the ground finches' main diet, they began observing the seed count and also the newtons necessary along with the measurements of each finch. Each year has a dry and a wet season. The wet season is a time when breeding begins and so it's the most lucrative time to come and watch.
Peter Boag and Trevor Price were on the finch watch at the time of the drought. There was one large rainfall at first dropping 3 inches of rain and then the rain stopped. Only the early breeders bred that year and no rain came. The seeds found were sparse and were harder to crack. The seeds had gone from being about a 1 on average on the struggle index to about a 6 on average. The main seed left was the Tribulus seed. This seed was very hard and only the magnirostris and very large fortis were able to crack these. Smaller finches left after trying for a couple of seconds.
Since the only seeds that were left ere extremely hard and finches need a daily supply of seeds selection favored the larger finches. The average depth of a finches' beak went deeper and deeper as the smaller finches died off because of starvation. This is not necessarily evolution by competitive exclusion because the birds are in their own specified niche. No species was driven to extinction but the fuliginosa were hurt population wise.
This trend continued, as they did not have a large wet season for nearly 3 years. At some point this trend had to stop other wise there wouldn't be 3 distinct species of ground finch. There had to be some sort of breaking point or the fuliginosa would become extinct. Not much breeding had occurred because of the rainfall and the deaths of fuliginosa out rated the births. This was much like a depression in the economy, where a chain reaction took place and sent things spiraling down. But droughts must end at some point.
Lisle Gibbs was on the island watch when the spiral broke. She had been sent a post card from the villagers from the town near by that said two words: It's raining. She quickly got down to Daphne Major and was drowned in the numbers of bandings she had to do because of all the breeding. Many males and females had more than one partner and the breeding didn't stop when the "dry season" began. The rain didn't stop either.
The culprit blamed for the rainfall was El Nino or the child. This weather phenomenon comes around once about every 3 years and is named for its occurrence during the time of the Christmas celebration. This is caused by an unusual warming trend in the waters and produces immense amounts of rainfall and precipitation.
During this time seeds and finches flourished, and most importantly the fuliginosa flourished as well. The seeds found in a given area were down all the way to below 1 on the struggle index and that made population spiral up for everyone except for the cactus finch.
Cactuses thrive on dry hot conditions. Since those conditions weren't present, the cactus finches took up the over flowing niches of the tree and the ground finch. They now only needed to use their specialty in times of need.
Many previous evolutionists that relied on fossils thought that evolution only occurred in long periods of time. This is true in some cases and in others can be false. A measurement used by evolutionary scientists is a darwin or a one percent change in a trait of some sort.
Looking at fossils as the only record many people believed that evolution couldn't occur because in fossil samples that were approximately 1000 years apart they never recorded a change even near 1 darwin. Therefore, fossil records were not the only factor in studying evolution.
In the year by year study the Grants recorded a change of 25,000 darwins during the drought and 6,000 darwins during the flood. The reason this does not occur in fossils is that rarely will one ever find a fossil that is during back to back years so the see-saw movement happens without any notice in the fossil record.
Evolution happens when niches are opened so that when there is an over abundance of a certain material or thing that no thing is competing for a species may diverge for the sake of using that niche. Evolution occurs by natural selection for certain jobs. When drawn out in a graph the populations and the depth of the finches' beaks to the nearest tenth of a millimeter there is drawn 3 bell curves signifying the 3 species of ground finch. They all have specific jobs and are reduced when parts of that job are scarce.
Natural Selection occurs when a natural event happens that makes those jobs scarce and then in turn has the spiraling effect on species. The 3 closely interlocked species of ground finch were the perfect model for exemplifying the power of Darwin's theory of evolution by the means of natural selection.
