Analysis: Particular traits can be advantageous to an individual by allowing the species to survive and produce more offspring than those without the trait, though different environments, such as the drought and monsoon used in the lab, can alter how beneficial a trait is. In “Land of Plenty,” the small beaks were most successful at collecting seeds; in “Drought 1,” the large beaks were most successful; and in “Drought 2,” the small beaks thrived. The “Land of Plenty” environment provided a plethora of both small and large seeds. In total, each group collected an average of 60 small seeds, and an average of 29 large seeds. Land of Plenty was successful because there were appropriate amounts of food for both types of birds, and therefore, none of the finches …show more content…
Because the finches would need to gather more than the 80% limit of food to survive, the small finches died out in Drought 1. This is because they collected an average of only 1, and they needed at least 48 seeds to survive. Overall, the large beaks collected more seeds than the small beaks during Drought 1. During Drought 1, the large-beaked finches were at an advantage because their large beaks, simulated with snub-nosed pliers, were strong enough to easily crush the large seeds. Above that, the large seed fitted securely inside of the large beak, unlike the small beak, where the large seed was constantly slipping out when trying to crush it. Aside from the seed slipping out of the small beak’s grasp, it was also difficult for the small beaks, simulated with tweezers, to crush the large seeds simply because they were too weak. The last food condition (Drought 2) produced only small seeds. An average of 71 small seeds was collected by each group, and an average of 52 large seeds was also
The four-pointed forkbird has the best suited evolutionary fitness. By the end of the activity, there were only two two-pointed forkbirds, one one-pointed forkbirds, and seventeen four-pointed forkbirds. This shows that four-pointed forkbirds have a better chance of surviving and passing on their traits.
The books “Fertile Ground, Narrow Choices” by Rebecca Sharpless and “The Path to a Modern South” by Walter L. Buenger paint a picture of what life was like from the late 1800’s to the 1930’s. Though written with their own style and from different views these two books describe the modernization of Texas through economics, politics, lifestyles and gender roles, specifically the roles of women during this era.
During the next five years there was a drought and only block plants grew. Our finch population steadily decreased during this time period because our finches could not pick up the seeds. They were much too large for their medium sized beaks. Our finches were not well adapted to the block plant seeds.
Stangel, P. W., Lennartz, M. R., and Smith, M. H. 1992. Genetic variation and population structure of Red-cockaded Woodpeckers. Conservation Biology. 6(2):283-292.
On year 6, the rain level was in the right range for the whooping crane population, with the amount of rainfall at 8.1 cm, and the snowfall at 4.6 cm. This great weather resulted in 8 nests, 8 eggs laid, and 4 eggs hatched. It might not seem like a major population growth, but with this specific endangered species, its population growth isn’t as quick as many other species. This was the main reason why it brought the attention to many officials to protect the whooping cranes from extinction. In this particular year, the hatching success rate was at a 50%, which is surprising because this year was the one who brought up the population well, into year 7. The amount of rainfall in year 7 was 7.4cm, while the snowfall was 0.0cm. Once again, these were perfect conditions for the whooping cranes. This caused the overall crane population (including chicks), to increase by 8 cranes, from year 6 to year 7. The hatching success rate was a high of 83%, the highest it has ever been in the 16 years of data! You can obviously see here that these low precipitation conditions are very beneficial to the overall growth of this
People normally tend to assume that plants in the past vary in differences and traits compared to species that are present. People have the impression that the past species had diverse weather conditions and nature related incidents forcing them adapt and become different from others. In the book, Andrew Knight had the idea that the food that was available could have tampered with their genes. Reproduction could have something to do with species changing. With plants, minor situations could determine whether they disperse a seed. It happens quickly and changes the genes of the plant causing a new formation that is disseminated through plant. Reproduction inheritance of genes is an important aspect when trying to determine ancestor’s life. By studying these pigeons, Darwin decides that all pigeons have originated from the rock-pigeon. Many people believe that pigeons have descended from a numerous amount of species and birds. Pigeons mate for life and by doing so the breeds are kept together and have markings in same areas of body. They mold into different species as years have passed because of the natural selection or an idea that Charles called unknown selection.
The results of natural selection in Darwin 's finches and British Columbian sparrows change my view of species because every living animal changes to survive conditions that get in the way of normal life.
According to Klug, &Ward (2009), members of a certain population from another are distinguished by the presence of unique genetic characteristics. It is believed that large populations have greater diversity of alleles, compared to the small populations. In most cases, the diversity of alleles designates a greater potential for any evolution of new genes combination. This also shows greater capacity for evolution in adapting different environmental condition. On the other hand, individuals in small populations are possible to be hereditarily, anatomically as well physiologically more consistently than in large populations.
In 1986, Garrett Hardin wrote an article about the population problem we have in our current world, and presented it to a big highly educated audience. He basically told them about the population problem we are currently going through in specific terms. First, he studied the relation of our current population to our current resources, and realized that our population should be brought under control because of the limited amount of resources we have. He then examined the actions that have caused population to increase uncontrollably.
Females like to choose mates who have very bright colors as it is a sign of the male’s good health and vigor. The natural and sexual selection can affect populations in three ways: directional (environmental conditions change in a consistent direction; one extreme of phenotypes is favored), stabilizing (environmental conditions are relatively constant; intermediate phenotype is favored), and disruptive selection (environment has more than one type of useful resource; both extremes of phenotypes are favored). An example of directional selection is pesticide resistance since only the insects with a resistance are favored; an example of stabilizing selection is that the smallest lizards have a difficulty defending their territory whereas the largest lizards are most likely to be eaten by owls; an example of disruptive selection are the black-bellied seedcrackers since they either have a large beak (which they can use to eat had seeds), or a small beak (which allows them to eat soft seeds). Disruptive selection shows a balanced polymorphism, which is when two or more phenotypes are maintained in a
Some individuals have developed different traits to help them in the process of intra-sexual competition. The organisms with more distinctive traits have greater reproductive success. More genes of those traits are then ‘selected’ and are passed onto the offspring of the organisms. Throughout time variability in these traits becomes
8. Taylor, Dan. 1998. Audubon Society Inspired to Action by Bird Die -offs . 17 Jan. 1998 . E-mail . Available bkus@sunstroke.sdsu.edu
Roberts W. M. (1996) Hummingbirds’ nectar concentration preferences at low volume: the importance of time scale. Anim. Behav. 52: 361–370.
Zacherl, Danielle. “Biology 171 Evolution and Biodiversity.” National Association of Research in Science Teaching 2007 Annual Meeting, New Orleans LA. (2007):n. page. Print.
...s. There would be severe overcrowding if they just fell where the parent plant is located meaning that the seeds would not get enough sunlight, water or space to grow and develop properly. If all members of a species were to be crowded together in one area it would make them more susceptible to risks such as fire or disease. By the dispersal of the seeds covering a wider area the chance of this happening would be greatly reduced (11). There for seed dispersal is necessary to help ensure as many seeds as possible have a chance to grow and develop properly, so that they are able to then develop seeds of their own (8). The loss of herbivores such as the wild ox (bos primigenius) in the Caledonian forest has deprived that area of an important dispersal agent but there are still other herbivores such as rodents that can still help maintain the dispersal of seeds (11).