Directions:
- Save your report often as you fill it out, so as not to lose information.
- Use the report form as a single document, do not turn in separate reports for each lab
- Use the ‘Save As’ option to save your file as a Word 97 .doc file
- Save your lab report with this name: Last name, First initial, underscore V1. Thus Charles Darwin would save his Unit 1 Virtual Lab Report as DarwinC_V1.
- Submit this report as a single document in the Dropbox under [Unit 2: Virtual Labs]
Virtual Lab 5: Ecosystem simulator
Purpose: The purpose of this simulator is to study the changes in the ecosystem based on natural selection and the food web.
Lab Observations: I was observed that it was difficult for a single species of plant (producer) to survive in an ecosystem that was pre-dominant with other plant species. It was also observed that there can be variations in the producer’s population based on the increase or decrease of herbivores or omnivores.
It was also observed that on inclusion of a top predator had significant impacts on producer population. Predators fed on Omnivores and herbivores. This led to decreased grazing in fields that led to increase in plant population.
Lab Answers:
A. In a couple of sentences describe what happens when you start with only two (A&B) and then all three plant species present. The number of Plant A population rises exponentially, and it was also observed that the there was a rise in the number of plant B population but to a low extent. There was a total of 3427 Plant B while 10,000 Plant A were observed.
B. Describe how many herbivores and omnivores you added (and what they eat) in order to create an ecosystem in which all three plant species can coexist. (If you cannot accomplish the survival of Plant C describe your best configuration. Describe your ecologies by identifying the species present and their diet, for instance:
Omnivore A eats Herbivore A, Herbivore A eats plant A and plant B; Herbivore B eats plant A, All plants present.
I used all 2 plants in the simulator. I analyzed all methods to save Plant C but couldn’t achieve the best results. My ecology system consisted of 3 herbivores. Herbivore A fed on plant A. Herbivore ate plant A and Plant B. I then used 2 omnivores to check if plant C could survive. Omnivore A fed on both, plant A and Plant B. I also included a top predator that fed on both, Herbivore A and Omnivore A. Omnivore C fed on Plant A and Plants B. Omnivore B fed on herbivore A and plant A. It also fed on plant C.
C. If you can accomplish part B, see if you can get all of the species to coexist. (Limit your time on this entire experiment to 90 minutes)
D. If we assume that this simulation is a reasonable oversimplification of a typical ecosystem food web what does it tell us about biodiversity and ecology- are they robust or fragile? In general is an ecosystem’s biodiversity preserved as it responds to change?
The ecosystem can be estimated to be fragile. Each component of the ecosystem is dependent to the other in some form. There is rapid change in a single ecosystem after every single generation of a species. The principle of ‘Survival of the fittest’ can be put in such a case. The biodiversity of an ecosystem is preserved to some extent. However, if compared to a long run different species dominate over an ecosystem now and then. There is no conclusion to which species or organism would survive for long in an ecosystem.
Conclusion:
The stimulator enlightened me about the ecological system and food web. Different ecosystems have different classes of producers, primary and secondary consumers. The simulator helped in depicting a life-like ecological system and enabled me to study different characteristics of a food web.
It also broadened my knowledge on food chains and food web. The simulator depicted a grassland ecosystem with primary and secondary consumers that formed the food web. A top predator was also included during the study to check for consumer and producer population. It enabled the learner to enhance the survival of a producer on the basis of computer generated algorithms. This can be implied in real-life situations where species are becoming extinct.
Virtual Lab 6: Evolution
Purpose: The purpose of this simulation was to demonstrate the relationship of science of natural selection and evolution in guppy population.
Lab Observations: There were changes in the color of guppies after 5 generations. A change in the color within the population varied. The color on guppies was based on the number of predators in the pond. It was also observed that higher the number of predators higher was the number of drab guppies.
However, female guppies preferred colorful and bright male guppies for mating. This could lead to exchange of genes of only colorful male guppies. There could be a possibility of the next generation to have genes only derived from colorful male guppies.
Sex and the Single Guppy
The first experiment consisted of a mix of drab and colorful guppies. The number of Drab guppies was kept higher. After 4 generations, 227 male guppies were present. Of the total male population, 42% males were bright and colorful. Nearly 7% were moderately bright. A considerable number of male guppies were drab and lacked colored spots. They accounted to 34% of the population. Drab fishes with some spots on the body consisted to nearly 18% of the population. The number of colored male guppies was in accordance to the number of predators and genetic exchange.
The second experiment consisted of 100 guppy fishes at start. Unlike the previous experiment, the study consisted of a mixture of drab, colored and bright fishes. Inclusion of 4 different predators was seen in this study. The number of predators, rivulus, acara and Cichlids were 30 each. After 5 generations, the color of guppies was studied. Out of the total 171 guppies, nearly 85 male guppies were drab and had no color on their body. Nearly 15% of male guppies were bright and colored while 9% of them were moderately drab. The population was further analyzed after 7 and 12 generations respectively.
• What two selection pressures are operative?
The varying color in male guppies after generation could be linked to two external pressures. First being the number of predators within the same population, and the other being the process of sexual selection that lead to bright colored male guppies.
In the first experiment where the number of predators was lower in number, the number of colored male guppies increased over the next few generations. Colored male guppies are preferred by females and increase their chances of becoming dominant in the next generation.
On the other hand, the second experiment demonstrates the increase in the number of drab male guppies. The rise in the number was in context to the initial rise of predators. Drab colored guppies are easily camouflaged in the water and are their chances of being spotted by predators were low. This phenomenon is known as natural selection and is a survival tactic.
Conclusion:
Thus, it can be concluded that even small organisms like guppies change by the process of natural selection. The color of guppies changes in accordance to the number of predators and the female population.
Guppies that are colored and bright are preferred by females compared to male guppies that are drab. On the contrary, it was also seen that the increase in THE number of predators increased the number of drab male guppies, as well. Being drab in colored enabled them to camouflage themselves from predators. This could be attributed to genetic exchange and natural selection.
Virtual Lab 7: Anatomy and Dissections
Purpose: The purpose of this simulator was to study the anatomy of earthworms and sexual characteristics. The next section of the study was to enlighten the brain structure and evolution of the brain in humans.
Lab Observations:
Different reproductive and digestive organs of an earthworm were observed. Earthworms are hermaphrodites and have both sex organs. The clitellum is a secondary sexual structure that is responsible for mucus formation during copulation. Pair of sperm grooves were also observed. These are also sexual structures of earthworms.
Internal morphology of the worm was also studied. The digestive tract of earthworm was observed. Stomach, gizzard and esophagus of the worm was observed. The gizzard is a swollen structure and helps in food digestion. Followed by the gizzard is the intestine where secondary digestion of food materials takes place.
A. Dissections
Earthworm
- Identify items 1 & 2 on the external dorsal (back side) surface of the worm.
Item 1 is the earthworm’s clitellum. This organ is responsible for mucus production during reproduction. Item 2 is the dorsal blood vessel of the worm.
- Identify items 3, 4, & 5 on the external ventral (belly side) of surface of the worm.
Item 3 is one the pairs of sperm grooves. These extend from segment 16 to the clitellum. Item 4 shows the openings of the sperm ducts that are located on segment 15. Item 5 is the openings of the female genital pores. It is present on segment 14.
- Identify item 2 in the image of the worm’s internal morphology w/o the digestive tract.
Item 2 is the gizzard of the earthworm. It is muscular and important organ during the digestion process.
- Describe sexual reproduction in worms.
Earthworms have both sex organs (hermaphrodites). The sex organs are located between segments 9 and 15 respectively. Reproduction in worm takes place in a unique manner. Both worms overlap each other and exchange sperms. During the process of copulation, the clitellum becomes red. It secretes out mucus that forms a ring structure around the clitellum. After a period of 4 to 5 hours the ring is out loose, and the worm allows sperms of different worms to enter it. When the ring slips out of the worm cocoon formation begins. The cocoon consist of embryonic worms and are lemon shaped. Embryonic forms look like adult earthworms but lack sex organs. Sex organs develop in 50-60 days while it takes around a year for complete development of an earthworm.
B. Comparative Hominid Anatomy
• Compare the skull casts of a chimp, Australopithicus, Homo erectus, neanderthal, and modern Homo sapiens. Be sure to use the lateral view.
The skull casts of the 4 distinctive phases of human evolution shows us that there has been rapid change in brain density and external morphology. The main difference is that the cranial capacity is the highest in Homo sapiens and that being >1000cc. In primates, like chimpanzees, the cranial capacity was found to be around 300cc. The lateral view of their skull casts, chimps had a larger and broader skull while modern humans (Homo sapiens) have a smaller one. Teeth of chimps showed grinding action while in Homo sapiens they showed crushing action.
• Describe features that are common and different between the cranial structures of these creatures. What patterns do you see? In chimpanzee’s, the canines are larger and project outwards from the tooth row while in Australophits canines are lager but are not protruding outwards. In modern humans (Homo sapiens) canines are equal in size. In each of the three distinct phases of evolution, canine size is determined by sexual dimorphism. In primitive chimps, teeth enamel was thin while in modern humans it is thick. The other similarity between the three phases is that the scapulae is present on the back, and the shoulder joints are shifted to the sides.
• Describe the basic timeline and sequence of evolution for the creatures listed above.
The timeline sequence in the simulator shows 3 distinctive phases of human evolution. The fourth and the oldest form is that of the Chimpanzees. The next phase is that of the genus Australophits. Australophits are considered to be intermediate between primitive and modern human evolution. Australophits showed modification and adaptation that led to the human evolution. The next phase of evolution is Homo erectus which is followed by modern day human and Homo sapiens.
Conclusion:
The simulator enlightened us about the anatomy of the earthworm and its comparison to the human anatomy. It was observed that earthworms are hermaphrodites. They possess both sex organs. Internal morphology of earthworm was also studied revealing the digestive system of the worm.
The next simulator enlightened us about the evolution of man. Skull casts, and general anatomy of each evolutionary stage was compared and studied. It was also observed that Austrolophits were distinct from primitive man and helped in the evolution of modern day human.
Virtual Lab 8: Human Impact
Purpose: The purpose of the simulator was to study water crisis on a global scale. The other purpose was to study the science of carbon and water footprint.
Lab Observations:
Water crisis in Ogallala was studied. It was estimated that 3.4 million people die due to consumption of non-drinkable water. There is an inadequate supply of water in different parts of the world. Observations were made on the amount of fresh-water utilized by an individual and community on the whole. Different software have been devised. This would help in reduction and wastage of water in prime areas. The science of carbon footprint was studied. The impacts of greenhouse gases on climate change was also studied. tHE software was used to calculate individual carbon footprint.
Lab Answers:
- Water footprints
• Describe the water crisis. What's its impact on women and children? What is happening with the Ogallala? 70% of the world is made up of water yet there is inadequate water supply to nearly 15% of the world population. Inadequacy of drinkable water to a population is termed as the water crisis. 3.4 million people around the world die due to water-borne diseases. Majority of the reported cases was of diarrheal diseases. The impact of scarcity of water is seen in women and children. Places where water is scarcely found, women and children have to travel miles to collect water. Most people living in such areas live in rural settings. Women and children also suffer from lack of nutrition and sleep. Traditional methods are used to cook food. The use of wood as fuel for cooking causes indoor pollution. This has adverse effects on children and women.
Fresh-water reservoirs are depleting at higher rates every year. In India, many grain-producing areas where water reservoirs are present are depleting at the rate of 6 to 10 feet per year.
A similar threat has been observed in US irrigation system. The plains of Ogallala are considered to be the prime source of water for irrigation. Over the years, the rate of fresh water being removed from these sources is increasing. This has led to increase in sea-water into such sources making it difficult to irrigate crops. Water from such sources cannot be used for drinking purposes and thus a threat is on its way.
• Describe what the water footprint is and how it is estimated. Water footprint is the measure of both the direct and indirect way an individual consumes fresh-water. Water footprint is also applicable to industries and communities. Different software is now available to estimate the water footprint of an individual or community as a whole.
• Report the two estimate of your water footprint (and the calculator(s) that you used). My estimated water footprint according to Water footprint network calculator (quick) was 539 cubic meters per year. The other tool used to calculate my water foot-print was the National Geographic water footprint calculator. My estimated water footprint was 630 cubic meters per year.
• Describe three ways that you (or your society) could reduce your water footprint.
Water footprint is an estimate of water consumed by an individual or the society as whole. As an individual, I would make sure that I close the tap while I brush or shave. I would also ensure that there is minimal use of water while gardening and washing my car. As a society in whole, I would chlorinate or treat the swimming pool water rather than emptying and re-filling the pool.
Carbon footprints
• Describe what has happened to atmospheric CO2 over the last 100,000 years and how this is thought to be impacting the climate. The amount of C02 being released has increased exponentially over the years. This rapid increase of CO2 and other Green-house gases are the major cause of climate change and global warming. 3 factors have been said to cause changes in climate. These are the changes in the greenhouse effect, changes in the sun’s radiating energy and changes in the atmosphere and reflective nature of the atmosphere of earth.
• Describe what the carbon footprint is and how it is estimated. Carbon footprint is defined as the amount of carbon dioxide and other greenhouse gases by an individual as a result of the biological and physical activities done. This increases the amount of greenhouse gases in the atmosphere that can increase global warming.
• Report the estimate of your carbon footprint (and the calculator(s) that you used). The estimated carbon footprint using cool California was around 34.5 tons CO2/year. The next tool used was cool climate network, and it estimated my carbon footprint to be 39.6 tons CO2 per year.
• Describe two ways that you (or your society) could reduce your carbon footprint.
At home, I would ensure that my room is properly insulated while the Air conditioner is being operated. This would result in decreased electricity consumption. The second step I would include to reducing my personal carbon footprint is that I would either walk or opt for a bicycle. This would reduce air pollution.
• Describe two approaches to lowering our carbon footprint as a nation that you would advocate we adapt society wide.
If all companies and industries in the country follow a simple policy of reducing, reuse and recycle, chances of reducing a nation’s carbon footprint would increase. The next alternative is to use bicycles or green fuel for transport. Use of public transport instead of private would help in reduction of Green-house gases.
Conclusion:
Water and air that form the basis of human living are posing to be a threat in the near future. Corrective measures should be taken to reduce the impacts of globalization and industrialization on such ecosystems.
The simulator enlightened us about the concepts of water footprint and carbon footprint. The crisis of fresh water resources should be solved immediately to avoid fatal consequences. Places like India and US have already faced water crisis and resolving the issue is a huge task. The next concept was that of carbon footprint. The use of automobiles and equipment for comfort of man has increased his individual carbon footprint count to higher levels. This should be reduced to save the atmosphere that is slowly being engulfed with greenhouse gases.
References
Carbon footprint Measurement. Carbon trust educational website. Accessed: 12 February 2014. Retrieved from: http://www.carbontrust.com/client-services/footprinting/footprint-measurement
Water footprint Measurement. Water footprint educational website. Accessed 13 February 2014. Retrieved from: http://www.waterfootprint.org/?page=cal/waterfootprintcalculator_indv
