1. (2 pts) Differentiate between artificial selection and natural selection. Make sure you define both processes in your answer and give an example of each.
Natural selection is when different organisms have evolved enough to survive longer and produce for offspring. for example, green treefrogs so not survive long in pine tree forests because they have no way to camouflage themselves, on the other hand brown tree frogs can hide better and aren’t as recognizable by predators like snakes and birds, therefore they live long enough to produce more children. Artificial selection is breeding for certain traits, such as dogs, we want specific breeds to express certain traits, i.e. German Sheppard’s crouch at the back legs, American Bulldogs to have large heads and small bodies, and we have even bread larger dogs with small breeds to have the coloration that we live and the hair type; Pomsky’s are the combination of a Husky and a Pomeranian.
2. (1 pt) Describe how the mechanism of natural selection has resulted in bacteria that are resistant to antibiotics.
Bacteria reproduce at a faster rate than the antibiotics we are given so the ones that survive the antibiotics adapt and then their offspring also contain that mutation, the cycle continues on and on so new antibiotics are constantly being created in attempts to beat the bacterial evolutionary arms race.
3. (1 pt) Are the principles of Darwinian evolution still supported by experiments in modern biology? Why or why not?
Yes. Because according to Ker Than, Live Science contributor, past fossils still prove that evolution exists and new fossils are proving that their skeletal structure is the very similar. For example, prehistoric whales were once land dwelling creatures that had legs and modern-day whales skeletal structure reveals that they still have legs but they are now vestigial bones because whales are now ocean creatures.
4. (2 pts) How are homology and convergent evolution similar? How are homology and analogy different?
Homology is different from analogy because homology is the similarity of structure, physiology, or development of different species based on their descent from a common ancestor. Analogy is a functional similarity of structure but not based on a common ancestor but only on a similarity of use. Convergent is similar to homology even though the organisms are not closely related, they independently evolve similar traits because they must adapt in order to survive in similar environments.
5. (3 pts) Critics deny that the fossil record provides intermediate forms that demonstrate the origins of higher taxa. Of Archaeopteryx, some of them say that because it had feathers and flew, it was a bird, not an intermediate form. Critically evaluate this argument.
Just because the Archaeopteryx had feathers and flew does not mean that it was a bird, it could have expressed other features of land animals that could make it an intermediate. The critics are excluding all other features that the fossil possessed and solely basing their idea on the feathers and flight. Flying squirrels spread their wings and glide from tree to tree, they may not have feathers but they do fly. Just because they fly and they have wings, it does not make them birds.
6. (2 pts) Briefly describe the environmental problems that result from population growth in both developing and developed countries. Include your thoughts on the Hans Rosling washing machine video in this answer.
As populations increase it leaves room for an increase spread of disease, lack of resources, introduction of foreign diseases, death of wildlife, an increase in greenhouse gas emission which leads to ozone depletion. In developing countries, the resources that we as American’s have are very limited, in places such as the Congo there are women who go was clothes in filthy, polluted water just to provide for their families when we can go to a community laundromat filled with machines when our personal ones aren’t working properly. In the video, as population grows so does the amount of income that individuals make and they are able to move up from the poverty level. But as population increases so does the cost of living which makes it harder for those who have nothing.
7. (2 pts) Contrast allopatric and sympatric speciation. Think of an example for each type of speciation event.
Allopatric speciation occurs when say an earthquake forms a fault line that makes it impossible for a once population to mate which then changes their environment, the grasses aren’t the same neither are the trees and foods available, if the fault somehow was filled in after a flood then the two species that were once one wouldn’t recognize the mating behaviors and they could not reproduce. Sympatric speciation would be like the lizards in Puerto Rico, they were all the same at one time but the resources then became limited so the lizards then moved to different parts of the trees and the grasses and developed traits to help them become more genetically fit. They all originated from the same species but evolved into separate ones.
8. (2 pts) Differentiate between gradual and punctuated models of speciation
Gradual change happens discreetly overtime where punctuated models express how some species go through a large change in a short period of time.
9. (1 pt) Explain why game managers in Colorado might maintain elk populations at half their carrying capacity rather than encouraging large populations that hover near carrying capacity.
Elk are very large animals and if their growth gets out of hand then the area would be overrun with them and the resources would then be scarce. Wild fires are also a rising issue in the mountains of Colorado and if there were too many Elk I believe that there would be less that survive due to overcrowding herds attempting to escape danger.
10. (2 pts) Inspired by the blue-footed booby, pick a bird species with an elaborate courtship ritual and discuss the evolutionary benefits and trade-offs of that ritual.
Peacocks have a making call and then they express their very wide and beautiful feathers to attract a mate. They are giving up looking for food and building a nest in order to reproduce and care for a female.
11. (2 pts) Define coevolution. Visit the site http://evolution.berkeley.edu/evolibrary/article/0_0_0/evo_33 and read the case study about squirrels and birds in the Rocky Mountains. What was the research question? Describe Benkman’s experimental research predictions. Were the predictions supported by the evidence?
Coevolution is when some species interact at a personal level and develop alongside each other that they evolve at the same pace over a given period of time. The question is “has coevolution happened?” The researchers predicted that the differences in pinecones had to do with their geographical region and different regions have different species of predators present in those areas which then changes that prey species. The predictions were supported by evidence of the birds having a better advantage to gathering seeds due to their beaks rather than the squirrels.
12. (4 pts) Select a biome. Where would you travel in order to see an example of it firsthand (please be specific – “to Africa” doesn’t tell me much of anything)? What plants would you see? Which animals would you be most interested to see? What concerns might you have about the impact of humans in that area?
I would travel to Queensland, Australia to the Tropical biome. I would be incredibly interested in seeing Platypus’ and Koala’s. Queensland is on the coast of Australia and has an exceptional amount of tourism. These animals live in the woods and by streams so I believe that hiking trails would be present and there would be signs posted telling humans not to touch them if they see any form of wildlife.
13. (6 pts) Define conservation ecology. Provide a local example of conservation efforts. Visit the Yellowstone to Yukon Conservation Initiative Website at http://www.y2y.net. What does this project hope to achieve? Why is it important? Do you think it’s a good project? Why or why not?
Conservation ecology is preserving without having a negative effect of waste and decay that would harm wildlife. We could reuse bags, bottles, and dispose of them in appropriate waste containers to ensure that the wildlife do not attempt to eat it. The projects goal is to increase highway safety along U.S. Route 20 in Idaho. An important part of this project isn’t only for human safety but wildlife safety as well. I believe that this project is good because it will allow for urbanization due to transportation travel but it won’t affect the habitat of the animals in that area nearly as much.
14. (5 pts) In a population of 1000 fruit flies, 640 have red eyes while the rest have sepia eyes. The sepia eye trait is recessive to red eyes. If the population is in Hardy-Weinburg equilibrium, how many individuals would you expect to be homozygous for red eye color?
160 fruit flies are homozygous dominant for red eyes. The numbers I used were as follows: .16+2(.4)(.6)+.36=1; p^2+2(p)(q)+q^2=1.
15. (15 pts) Visit the IUCN Red List. Select one terrestrial animal, one aquatic animal, and one plant that are endangered, critically endangered, or extinct. Describe their life history traits (lifespan, r/K selected, habitat, trophism), geographical distribution (biome and range), and evolutionary adaptations to their environment. Describe the biggest threat facing their populations and identify any conservation efforts currently planned or underway to mitigate these threats.
Achyranthes mutica- Blunt Chaff Flower
• Critically endangered
• Lifespan: Perennial plant
• R-selected
• It lives in dry forests and gulches of Hawaii, it grows in Monsoon seasons.
• It is an autotroph
• It is native to Kauai, Hawaii in the Kohala Mountains and it is considered to live in the Dry Tropical Forest biome.
• The major threats it faces are being grazed upon by livestock such as cattle and goats. It is at risk of being taken over by alien invader species and fire. They are slowly introducing the species into the wild and also captive breeding. The remaining wild subpopulations are monitored and cared for by private landowners.
Acipenser sinensis- Chinese Sturgeon
• Critically endangered
• Lifespan: anywhere from 16.5 to 20 years
• R-selected
• They spend part of their life in salt water but return to rivers to breed, their young live in estuaries. As they become sexually mature they move up river, they are native to the Northwest Pacific region (Japan, China, and Korea).
• They feed on zoobenthos and small bottom invertebrates, at one time they ate clams but adapted to eating worms because they were more abundant.
• Evolutionary adaptations they possess are how they use their mouth as a shovel to dig for worms since they don’t sit on the surface and clams aren’t nearly as accessible.
• Their population was extremely threatened in the 1970’s because of overfishing and they haven’t recovered. Conservationist have made it illegal to catch them since 1983 but now they are allowing them to be caught in small numbers. Sturgeons are also being caught in order to use them in fish farms to try and raise the population number.
Elaphurus davidianus- Pere David’s Deer
• Extinct in the wild
• Lifespan is anywhere from 18 to 23 years
• K-selected
• They were native to China’s lowlands, commonly found near marshes.
• They fed on mainly grass but in the summer, they fed on many aquatic plants.
• Their population took a detrimental hit because of overhunting and habitat loss, some of the deer were captured and captivated but there are no more free range wild Pere David’s Deer. They are in National Parks and in zoo’s but that is the only place to see one.
16. (5 pts) For questions A to E, analyze the situations described. Then explain which of the following ecological principles could be active in each particular situation.
Ecological principles:
Coevolution Realized niche Fundamental niche
Competitive exclusion Resource partitioning Character displacement
Trophic structure Keystone species Competition
Tolerance Disturbance Top down vs bottom up control
A. A small clan of hyenas killed an antelope. While they were feeding on the carcass, two female lions approached, growled at the hyenas, and chased them away from the carcass.
I believe that the action taken by the Lioness’ had to do with competition because they actively kept the Hyenas away.
B. Two species of closely related swallows live in England. The black swallow lives in coniferous forests, and the yellow swallow lives in deciduous forests. In Ireland, where the black swallow has never been introduced, only the yellow swallow is present and it lives in both coniferous and deciduous forests.
The swallows in England have found their realized niche because they know the resourced they need and they cannot get them in the same areas. The yellow swallows in Ireland are the only species there so they have the fundamental niche due to them not having a limiting factor.
C. In a woodland community, three species of rodents coexist: voles, field mice, and shrews. All three species eat seeds and nuts. Each species has a preference for seeds of the most appropriate sizes for their teeth and mouths; however, all three species compete for the same kinds of nuts. An owl species also lives in this woodland community. The owl preys on all three rodent species. During one particular year, a parasite that causes pneumonia in birds is introduced into the community. This dramatically reduces the owl population, which remains low for several years as a result. Following the initial reduction in the owl population, there is a dramatic increase in the population of field mice and a dramatic decrease in the populations of both voles and shrews.
This is related to trophic structure due to the lack of prey on the rodents their population rose tremendously but the nuts they eat then became extremely scarce because there weren’t enough resources to support the number of animals that were eating it, field mice were more equipped to survive.
D. In 1962, five mute swans escaped from captivity and began a breeding population in Chesapeake Bay. Today, there are over 4,000 mute swans living in the bay. Each year they eat approximately 10.5 million pounds of aquatic grasses. These grasses provide habitat for waterfowl and crustaceans, improve water quality, decrease erosion, and increase dissolved oxygen concentrations in the bay. The swans are also aggressively territorial, and have been known to trample nests of other birds (e.g., least terns and black skimmers) and drive native birds such as tundra swans and black ducks from feeding and roosting areas.
Competitive exclusion because they have taken over the bay area and they do not want any other bird species invading their claimed territory.
E. Known as the “Hawaiian woodpecker,” the `akiapola`au (aki-a-pul-a-ow) is found only in montane mesic old-growth koa/ohi forests, and only on the Big Island (Hawaii). It has a distinctive beak that is like a multiple-use tool. The short straight lower mandible is used to peck holes in the wood and the long curved upper mandible is used to probe for insects and larvae. Males have larger beaks than females and feed on the trunks of trees. Females feed higher on branches and twigs. ‘Akiapola`au are thought to have the lowest reproduction rate for a small bird—only one chick per year, which is cared for by the parents for 6 months or more. The decline in their numbers appears to correspond with the introduction of rats, cats, and logging on the island.
A Disturbance best fits this due to logging is only temporary.