Why Some Birds Would Survive And Reproduce More On Certain Islands Case Study

Therefore there was a recorded 8 birds, 1 dove, 5 magpie goose and 2 pacific black duck, 3 weeks after the floods. By 2017 the total of 8 birds, 3 species have now increased to a total of 25 birds, 6 species in 4 years. Though this being said many of the birds are ‘new’ to the area such as the 15 Cotton pygmy Geese and 4 recorded Dusky Moorhen. 6 bird species were seen/recorded in 2017, these being the 2 Black cormorant, 1 pacific black duck, Cotton pygmy, Dusky moorhen, little egret and willie wagtail. Other bird species such as the magpie goose which had a number of 41 recorded in 2009, 5 in 2013 and now 0. This indicates that the diversity of birds and population has decreased as a result of their habitat loss and or an a adequate supply of food.

its eggs in other bird's nest. If it not were for the other species ignorance,

Darwin has listed different names for each bird, they are all variations of Finches, apparently descended from a common ancestor. However, each bird has a different length beak and many are differently shaped to allow them to more efficiently eat the available fodder. Coincidentally, Mr. Darwin failed to catalog specifically where each bird came from and had to ask the ship’s captain to supply this information along with his collection to Mr. Gould for identification and cataloging. An interesting part of the conversation between Mr. Darwin and the ship’s captain is the captain’s argument for the fixity of species, that each one was created by God exactly the way it was, and placed on each island, and that it is heresy to say that they came to be there any other way.

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

To compare the impact of evolution on different organisms a study was conducted by: carefully examining the species of birds with each other. This was accomplished through using a sample population of 200 birds. Moreover, there were other factors that were taken into account (in order to ensure objectivity and accuracy). The below table is illustrating those factors that were considered to be the most important during this study. ("Evolution Lab," 2012)

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 Galapagos Islands consists of thirteen major islands and over a hundred smaller islands located along the Ecuadorian coast. The islands are home to a variety of unique species such as sea lions, sharks, rays, and 26 different species of native birds. Thirteen of these birds are Darwin’s finches. These finches are known to be the “world’s fastest-evolving vertebrates” due to their bodies quickly adapting to the rapidly changing environment (Robertson, N.D. , para.1). Their DNA chemical makeup causes these adaptations to occur. The finch’s most noticeable feature is their evolutionary adaptations, due to the briskly changing environments.

For example, when there is little or no rainfall- a drought; the bird population steadily decreases, because birds are dying off due to the lack of rainfall. When rainfall became scarce, the food supply did too. The small seeds that birds with small beaks relied on dissapeared. The only food left on the Islands were large, hard seeds or fruits. The birds

Can you estimate the equilibrium number of species from the colonization curves? If so, what are they? If not, explain why not. Once an equilibrium number is reached, does it mean that the island becomes static, or might there be turnover of species? Explain. (3 points) We cannot estimate the equilibrium number of species for the colonization curves because the species number is still increasing slighty according to graphs. As species create new habitat on the island (the flat,clean boards were not so after being in the pond), these habitats may also be suitable for new species that move in. Thus the number of species continue to increase. Even if this does not occure and an equilibrium number is reached, it does not mean that the island becomes statis. One species might

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

Environmental conditions are sometimes appropriate for the evolution of numerous species from a common ancestor. Evolutionary, or adaptive, radiations happen when a large number of species descend from one lineage. This phenomenon usually occurs when a population of one species colonizes an area with many available ecological niches and when the rate of speciation is greater than the rate of extinction in a given area. Adaptive radiations have historically taken place after mass extinctions and on newly formed island archipelagos, because these incidences create conditions where new species can fill open ecological niches. Unlike the mainland, ecological niches are available on new island systems. These island species adapt to new environments

Krichman (2009) examined the ancestry of flightless birds (Gallirallus philippenesis) through the usage of genetic testing that were sampled throughout a range of ancestral species. This was to test a model of speciation where flightless birds were thought to have evolved from flying birds

While on the Galápagos Islands, Darwin kept notebooks about all the species there, and he noticed the variety of tortoises on the island who were essential in explaining his theory of evolution. There are several species of tortoise present on the Galápagos Islands that are all very closely related, but slightly different. There are eleven presently surviving subspecies of Galápagos tortoises; furthermore, six of the eleven are found on different islands in the archipelago, and the other five are all found on a single island on five separate volcanoes with their own mini-ecosystems (PNAS). Although all of the species of Galápagos tortoise is different, they each have small differences that can include maximum adult size, shell shape, and the length of the neck and limbs. The tortoises of the islands are most closely related to the Chaco tortoises along the western coast of South America, and they most likely came to the Galápagos by “rafting” across the water (PNAS). Similar to the tortoises, Darwin observed that the Finches on the islands also had changed to match the environment. Spread among the islands were fourteen subspecies of finch whose

Franck and Brownstone define biological diversity as 'the variety and variability of living organisms and the biological communities in which they live' (36). Decades of progress in both the scientific and political arenas have advanced environmental legislation to protect biodiversity at not only the ecosystem level, but for specific species and genetic material as well. Research has shown the importance of every organism and their role in the global ecosystem, and legislation has gradually matured to protect not only species which may become endangered, but the habitats they need to survive as well. Growing consciousness surrounding environmental issues has enabled these protections to be

to determine differences (if any) in densities of native and non-native birds relative to the type of vegetation present. Two native vegetation areas and two non-native vegetation areas were studied (i.e. four areas in total).