Paper Example on 500,000 Years of Bird Evolution: Mutations & Adaptations

Part A

This simulation represents 500,000 years. A bird population exists in the southwestern portion of the island. During this time, mutations may alter the ability of some birds and their descendants to thrive in the environment. Birds with traits that enhance their fitness are more likely to survive and reproduce.

In the southwest, your birds will encounter the environmental conditions listed in the table below. Fill in the second column of the chart with the bird phenotypes that are best suited for each of the conditions.

• Seeds Short beaks that are cone-shaped.
• Edible insects Wide beaks which seem to be short and flat.
• No nectar The thin long beaks will evolve
• Light green foliage Insect eaters will evolve into light green in body color to aid in hunting.
• No predators Body colorations are not based on existence of predators. Small body size is common.
• Of the phenotypes you selected for the three birds, how fit do you think each phenotype is in the current environment? Explain your reasoning.

Currently, the birds that eat seeds contain short beaks with a cone shape because they use the beaks to break seeds that seem to be hard for them to swallow. Insect eaters contain short and flat beaks which means that they can easily kill insects by their beaks and swallow them. The nectar eating birds contain long and thin beaks to allow them get access to nectar from deep inside a flower. When there is no nectar to eat, the beak will not be of use and according to the vestigial organs concept of variation, they will end up adopting different feeding characteristics for their survival. This trait may then be passed on to the off springs. Hence the first and second birds are the fit birds in the new environment.

Work with your group to assign each student one of the populations of birds to observe. Record the population you have been assigned.

Watch the animation. Record in the chart for your assigned population what changes occur (including mutations, mutation effects, and population numbers) in each population, and how many years have passed when the change occurs.

50,000 Single mutation in the second bird. The long beaks turned shorter since no nectar. No effect on fitness. The second bird ended up dying.

1: 299

2: 302

3: 366

100,000 Single mutation in the third bird. Their body grew bigger with less off springs inheriting such trait. Due to less number of offsprings, none of them survived to reproduce.

1:302

2:296

3:409

150,000 A single mutation in the first bird. The beak became curved. This adaptation is significant in adoption, however they died with time due to less numbers.

1:314

2:291

3:455

200,000 One mutation in the first bird. The body became bigger for adoption. The effect was aimed at avoiding the predators, however they died after some years.

1:327

2:294

3:509

250,000 There was a single mutation in the third bird. The beak became slightly curved for feeding on insects. Fitness is increased and the traits were passed on until now that they exist.

1:331

2:293

3:556

300,000 A single mutation in the third bird. The body turned yellow. No effect on fitness since the plumage promoted diseases.

1:330

2:299

3:736

350,000 A single mutation in the first bird was experienced; their bodies had an orange coloration. Fitness in terms of food and predators was not enhanced, the plumage promoted diseases hence they died.

1:321

2:304

3:886

400,000 The first bird experienced mutation; the beak became smaller. Fitness was not enhanced and they died.

1:326

2:307

3:1021

450,000 One mutation took place in the first bird. The beak grew longer. This had positive effect on fitness.

1:331

2:309

3:1186

500,000 There was no mutation, beaks remain slightly long with yellow, light green and brown plumage from the first to the third bird respectively. Their existence have benefits through handling food, diseases and predators.

1:329

2:316

3:1285

In your group, discuss how the bird populations changed over the course of the 500,000 years. Write a summary of your discussion. For example, what types of mutations occurred? Under what circumstances were the offspring more or less fit as a result of the mutation?

The first bird underwent several mutations to conform to the environment. For the longer beaks, they were able to kill insects and swallow them. The increased body meant that there were no predators. Mutation that resulted in light green color in the second bird was aimed at hunting of insects. Presence of seeds made the grains eaters to grow a sharp beak that is short for easier feeding, this was evident in the first bird. Due to no nectar, the nectar eaters had to decrease in number, those that survived had to transform into having short beaks, and this trait was passed on to the offsprings. When the birds underwent mutation for the purpose of survival, then it would be evident the mutation made them fit. Mutations that led to color change were seen to be disadvantageous as diseases came in to kill them.

Were your ideas about the fitness of each phenotype you selected correct? Explain why or why not.

The fitness ideas were correct because the mutations that took place helped in the survival of some birds. The first bird is among the birds that went through several changes to adapt to the environment. Through the adjustments in the length of the beak, the function of feeding on available insects was evident. Body color changes were best tactics in hunting. Different birds have to fit into the environment for them to survive and reproduce.

Part B

A hurricane has hit the island, and some of the birds have been blown to three new areas! Each area has a unique environment. Work with your group to assign each of you to observe one of the three areas.

Record in the chart below the environment that exists in each of the three new areas when each bird population arrives. Circle in the first column the name of the area that you have been assigned.

• Northeast: Plenty of seeds, predators and insects are absent and there exists some nectar.
• Northwest: No seeds, Plenty of insects, some nectar and plenty of predators.
• Southeast: No seeds, some nectar, no predators and some insects exist.

Discuss with your group which birds you think will be most fit in each new environment and which will be less fit. Record in the space below your ideas, and explain your reasoning.

The first bird will be best for southwest because the place contain insects to be fed on, the longer beak would aid in feeding on nectar. The Northwest is best for the third bird which eats insects; the medium sized beak will serve best in this function. The Northeast contains a favorable environment for the second bird; the light green plumage helps in hunting insects, the medium long beak may also help in feeding on nectar in the region.

Watch the animation for your assigned area. Record in the chart below the phenotypes of the birds in each population and their environment (food, foliage, predators) each time there is a change in the area during 500,000 years of evolution.

550,000 The first bird in northeast developed a curved beak as the second bird in the same place developed larger body size. The second bird in southeast developed longer beak. The second bird was able to feed on plenty of seeds in the northeast. With longer beak, the second bird in south east would feed on nectar and insects. Hence the birds were more fit. Plants developed a dark-green plumage in Northeast. Northeast: 1-160, 2-155 and 3-578.

Northwest: 1-198, 2-118 and 3-226.

Southeast: 1-310, 2-205 and 3-578.

600,000 The first bird developed a more curved beak in Northwest as the second bird developed a longer beak and the third bird developed a yellow plumage in the same region. The change in color had no effect on fitness, it led to diseases hence death in the first bird in Northwest. The second bird became more fit as the third one became less fit in the same region. Insects became available in the Northeast. Northeast: 1-193, 2-188 and 3-677.

Northwest: 1-205, 3-117 and 3-199.

Southeast: 1-442, 2-337 and 3-677.

650,000 The third bird in Northeast developed light green plumage. The third bird in Northwest developed a longer beak. The third bird increased fitness in Northeast as the third bird in Northwest also became more fit. Plenty of insects and predators became present. Foliage turned natural in Southeast. Northeast: 1-465, 2-392 and 3-983.

Northwest: 1-210, 2-183 and 3-197.

Southeast: 1-578, 2-473 and 3-779.

700,000 The second bird in Northeast developed a less curved beak. The third bird in southeast developed a light green plumage. The second bird in Northeast became more fit as the third bird in southeast became less fit. No changes were experienced. Northeast: 1-793, 2-638 and 3-1352.

Northwest: 1-215, 2-202 and 3-230.

Southeast: 1-630, 2-564 and 3-738.

750,000 The beak became shorter in the first bird from Northeast. In the Northwest, the first bird had a smaller body size. The first bird in Southeast turned orange. The first bird became fit in the North east as the first bird in both Southeast and Northwest became less fit. No changes were experienced. Northeast: 1-1169, 2-1014 and 3-1775.

Northwest: 1-211, 2-208 and 3-230.

Southeast: 1-677, 2-629 and 3-697.

800,000 Plumage of the third bird turned yellow in the Northwest. The beak of the second bird in Southeast became more curved as the body size of the third bird increased in the same region. The third bird became less fit in Northwest as the second bird in South east became good mates and the third bird became more fit. No environmental changes. Northeast: 1-1481, 2-1326 and 3-2126.

Northwest: 1-208, 2-213 and 3-235.

Southeast: 1-703, 2-668 and 3-692.

850,000 The first and second bird in Northwest developed a shorter beak. The third bird in Southeast grew bigger in body size. The first and second birds turned less fit in Northwest as the third bird in Southeast became more fit. No environmental changes. Northeast: 1-1745, 2-1590 and 3-2423.

Northwest: 1-204, 2-212 and 3-233.

Southeast: 1-704, 2-679 and 3-857.

900,000 The beak in the second bird from Northeast became less curved. In Southeast, the second bird had a shorter beak develop as the third bird turned light green. The second bird in Northeast increased fitness. In the Southeast, there was no effect on fitness f second bird. The third bird in the same region improved fitness. Insects' population decreased and nectar became depleted in the Northwest. Seeds became available in the Southeast. Northeast 1-2097, 2-1942 and 3-2819.

Northwest: 1-206, 2-210 and 3-236.

Southeast: 1-705, 2-681 and 3-989.

950,000 The second bird in Northeast reduced body size as the third bird's beak became more curved. The first bird in Southeast grew a shorter beak. The second and third birds in Northeast increased fitness as the first bird in Southeast had not fitness eff...