Geological Time Scale

3. Take notes on the activity and discuss the geologic time scale as you proceed. Make sure to include explanations for the following (you may include more):

a. Relative dating

Relative order puts events in order from earliest, to most recent.

b. Absolute dating

c. Approximately how old is the Earth?

The Earth is about 4,600,000,000 years old

d. When did life first appear on the Earth?

The first life appeared 3,900,000,000 years ago

e. Law of Superposition

Rock layers are deposited on top of layers that were already there. As more and more layers are deposited, the older rock layers end up at the bottom of the sequence and the newer ones toward the top.

f. Vertical timeline (what does it demonstrate?)

It shows the relative order of events and helps us see connections between events, records are kept to be easily put in order for evidence.

g. Trilobites

Trilobites ("three lobes") are so called because their bodies are divided into three lobes: a middle lobe and one on either side. They first appeared about 540 million years ago.

h. Brachiopods

Brachiopods are marine animals that look a bit like clams. They are still common in cold waters today, but the height of their diversity occurred about 400 million years ago.

i. Radiometric dating

Radiometric dating gives absolute dates using the molecular compositions of the substances surrounding fossils.

j. Eurypterids

The eurypterids were one of the fiercest predators in ancient seas. Some reached more than two meters (six feet) in length, making them the largest arthropods that ever lived. The last ones went extinct about 245 million years ago.

k. Ammonites

Chambered mollusc, similar to today’s mollusc

l. Geologic Time Scale

It represents the entire history of the Earth since its formation, roughly 4.6 billion years ago.The Geologic Time Scale is broken up into several periods of time, during which there were great changes in the biodiversity on Earth.

m. Name the Eons and their major events

-Pre-Archean was before Archean, no evidence supports life during this eon.

-Archean: “original”, this was when the first single-cell organisms began to evolve.

-Proterozoic means "before animal life" which isn’t accurate, but most organisms during this time were simple, this is when algae and worm-like creatures were evolving.

-The Phanerozoic Eon is when complex life started to form on earth. It began with the start of the Cambrian period, 544 million years ago, when most of the major groups of animals first appear in the fossil record, and continues through today.

n. Name the Eras and their major events

Cenozoic: “recent life” Mammals, birds, flowering plants became more abundant during this time.

Mesozoic: Mesozoic means "middle life." Dinosaurs, cycads, and ferns were abundant during the Mesozoic.

Paleozoic: “ancient life” Many animals of today originated then like certain corals and brachipods

o. Name the Periods and their major events

-Cambrian: when most of the major groups of animals first appear in the fossil record.

-Ordovician: known for its diverse marine invertebrates and for the presence of early vertebrates.

Silurian: Coral reefs first started forming and an important time for the evolution of fish

Devonian: The first plants began showing up and growing

Carboniferous: Coal began forming in large deposits, and insects began evolving

Permian: When all of the continents came together to form Pangea, and ended with the largest mass extinction in the history of earth.

Triassic: The animals that survived the mass extinction continued to evolve

Jurassic:  Plant eating dinosaurs dominated the earth. Smaller carnivores ate the larger herbivores.

Cretaceous: Ceratopsian dinosaurs came into existence. Many non-avian dinosaurs became extinct.

Tertiary: Many flowering plants evolved, as well as modern-looking mammals

Quaternary: Mammoths and mastodons, sabre-toothed cats, etc. roamed North America, Asia, and Europe. Most of the world temperate zones were covered by glaciers and uncovered by the warm periods.

p. When did humans come along?

Humans came along in the Quaternary Period along with mammoths, saber tooth tigers, etc.

r. What questions do you still have?

Origin of Life Think Quest

Origin Of Life Think Quest

Activities / Procedures:
1. In your small groups, read the following quote from a New York Times article:  “Enshrined in high school textbooks, the Miller-Urey experiment raised expectations that scientists could unravel the origins of life with simple chemistry experiments.”

2. Now, use your online textbooks and the following videos: http://www.youtube.com/watch?v=j9ZRHoawyOg and http://www.youtube.com/watch?v=63IoOLXmzKg(Familiarize yourself with the famous Miller-Urey experiments of 1953 by completing the following Think Quest that will prepare you for reading an article about new evidence related to these experiments.

Quest Questions (post answers in your online notebook under “Notes”:
-Who were Stanley Miller and Harold Urey? Scientists who discovered how organic, life substances could be formed under the conditions the atmosphere was under during the first years of the earth’s existence.
-What was the Miller-Urey experiment trying to simulate? The conditions of the atmosphere.
-When was the Miller-Urey Experiment performed? During the early 50’s.

-Describe the Miller-Urey Experiment. They recreated atmospheric conditions during the first years of life, and subjected them to either electricity or freezing, and observed what molecules were created.
-What was discovered by the Miller-Urey Experiment? That amino acids and adenine could be created under the above-mentioned conditions.
-Are the results of the Miller-Urey Experiment still considered relevant today? Why or why not? Yes, but by a much more varying degree from when it was first introduced. There are so many more hypothesis now, that the amino acids could have formed from meteorites from space.

--Compare and contrast this experiment to your “Coacervates Lab” (review it in your online notebook). We were able to create cell-like organisms through the use of carbohydrates and proteins.
- List any Need to Knows you have concerning the experiment and the conclusions. Did all of these organisms form together to make the first cells?

- What was the significance of the swan-neck flask experiments and who performed them? It proved that spontaneous generation did not exist, and there were no vital substances in the air for living. Louis Pasteur conducted this experiment.

- What was the significance of the blender experiments and who performed them? Alfred Hershey and Martha Chase used a kitchen blender to prove that DNA exists, and how viruses infect their hosts.

- How do the blender, swan-neck flask, and Urey-Miller experiments relate to one another and your current project? Through the incorporation of all of the created molecules, life is possible to be made. With our current project, we are talking about the evolution of animals, and the fact that the environment surrounding can affect organisms, we will be able to have our organism evolve.

3.  With your partners, read and discuss the article “From Old Vials, New Hints on Origin of Life,” (http://www.nytimes.com/learning/teachers/featured_articles/20081021tuesday.html) focusing on the following questions:
a. What would a proponent of Dr. Miller say about his experiment today? What would a critic say about it? They would say that there are so many variables in which life could have taken place. A critic would say that it is very improbable that anything of such degree could have taken place.
b. Why did the addition of steam to the experiment by Dr. Miller interest Dr. Jeffrey L. Bada? The H2O made for a better environment for chemical reactions to take place.
c. What did Dr. Bada and Adam Johnson discover in the “brown residue at the bottom of an old vial?” Why was it significant? There were more amino acids than originally conceived by man, and it helped the believe that – certainly – complex proteins could have been formed in these conditions.
d. What other places have been suggested as likely locations for the origin of life and why? Do you agree or disagree with Dr. Bada’s assessment that “you want to consider everything,” and why or why not? The ocean was considered. Yes, you do want to consider everything, because given billions of years, life had to start from somewhere. If simulated, then we can find the origins of life.

e. How does knowing about climate past and present help us understand life and how it survives? We are able to see under what conditions life can be sustained.

f. Do you think we have a responsibility to attempt to curtail or reverse human’s influences on the environment?  Why or why not? Yes, because we are the more conscious beings on earth. We subjected the earth to these conditions, and now we are responsible for bringing it back to a healthy state.

Evolution Reflection

1. Does evolution tend to proceed slowly and steadily or in quick jumps?

I think it varies. Clearly, humans evolved over thousands of years, and that was just a short span of time. For plants, it took millions of years. This shows that it is not the same for all species, and depends on the environment.

1. Why are some clades very diverse and some unusually sparse?

Depending on their location, some may need not evolve any more. If they have reached a point where they can survive with no problems, then they do not need to evolve to adapt to their environment.

1. How does evolution produce new and complex features?

Evolution produces new features, because organisms are constantly needing to adapt in the changing world. Because the world is experiencing a warm up period, life will have to evolve it's features to survive.

1. Are there trends in evolution, and if so, what processes generate them?

Yes, there is a trend. Organisms evolve based on their environment. This inclues predators, climate, and food supply. This all changes with, or without, the organisms. 

Evolution 10/24/13

• Evolution is descent with modification
• Evolution implies biological evolution
• All life on earth shares a common ancestor
• Phylogeny is the evolutionary tree at which species evolve, and is a hypothesis on the relationships among organisms
• Moving through a phylogeny is moving through time
• A split represents a branching on phylogeny
• Each part of the phylogeny is specifically unique
• They are trees, not ladders
• Characteristics of the animals/species help with ordering them
• The species that is most important to the biologist goes on the right
• Homologous characteristics are those that are similar among species
• Bird and bat wings are analogous, which mean they have separate evolutionary origins, even though they look similar
• It is used for classifying organisms, as well
• Linnaean system: Kingdom, Phylum, Class, Order, Family, Genus, Species
• A clade is a group that shares a common ancestor
• The chart allows for easy distinguishing of relationships
• Humans are very young
• Radiometric dating relies on half life decay to discover the times at which things lived
• Stratigraphy uses other dates to estimate the time
• Molecular Clocks allow genetic divergence between organisms for time estimates
• Descent and the genetic differences that are heritable and passed on to the next generation;
• Mutation, migration (gene flow), genetic drift, and natural selection as mechanisms of change;
• The importance of genetic variation
• The random nature of genetic drift and the effects of a reduction in genetic variation;
• How variation, differential reproduction, and heredity result in evolution by natural selection; and
• How different species can affect each other's evolution through coevolution.
• Mutation is an unnatural, random change of genes
• Migration is when two different species of organisms interact
• Genetic drift is when a certain type of organism is diminished, and less of that organism's genes will be passed down
• Natural selection is survival of the fittest
• Fitness is how well an organism can leave offspring alive
• Sexual selection is the ability for an organism to find a mate, easily. Sometimes, organisms go to extreme lengths to find a mate. If is not successful, it will not pass on its genes
• Artificial selection is when humans are involved in the process of sexual selection
• Adaptation helps for organisms to survive
• No such thing as a "perfect organism."
• Coeveolution is when two organisms effect each others morphology
• Microevolution - evolution on a small scale
• A population is a species that interbreed with each other
• The same species can look different, and the different-looking organisms can interbreed
• Speciation event is the birth of a new species
• Isolation causes speciation
• Speciation can also be caused by a difference in mating rituals
• Lack of fit of genitals
• Cospeciation is when two organisms effect the speciatition of another organism
• Macroevolution is evolution on a grand scale
• It is involved in the tree of life
• 3.8 billion years is macro
• Many species find a stasis, from which they will not evolve much
• Lineages can change quickly or slowly
• Extinction plays a big part in macroevolution

Osmosis and Diffusion Lab

Osmosis and Diffusions Lab Report

Mod. 19, AP Biology

Abstract. In this lab our group’s goals were to conduct multiple experiments in hopes to find a difference in our data. We used different amounts of sucrose in each beaker that contained the same concentrate of potato to see if we could reach a better understanding of diffusion and osmosis by recording the weights of the contents in each beaker. This lab experiment we conducted helped us understand the fundamentals and schematics of how diffusion and osmosis occurs.

Introduction

In this lab, we experimented with the process of osmosis and diffusion using potatoes, sucrose, and water. Foraging refers to the mammalian behavior associated with searching for food. The optimal foraging theory assumes that animals feed in a way that maximizes their net rate of energy intake per unit time (Pyke et al. 1977). An animal may either maximize its daily energy intake (energy maximizer) or minimize the time spent feeding (time minimizer) in order to meet minimum requirements. Herbivores commonly behave as energy maximizers (Belovsky 1986) and accomplish this maximizing behavior by choosing food that is of high quality and has low-search and low-handling time (Pyke et al. 1977).

       The central place theory is used to describe animals that collect food and store it in a fixed location in their home range, the central place (Jenkins 1980). The factors associated with the optimal foraging theory also apply to the central place theory. The central place theory predicts that retrieval costs increase linearly with distance of the resource from the central place (Rockwood and Hubbell 1987). Central place feeders are very selective when choosing food that is far from the central place since they have to spend time and energy hauling it back to the storage site (Schoener 1979).

       The main objective of this lab was to observe osmosis take place within potatoes and dialysis tubes. Osmosis occurs within and outside of cells. By examining the potatoes’ and the tubes’ mass, we hope to see the mass change. The purpose of this lab was to learn about the osmosis. We wanted to know potatoes and dialysis tube can show signs of a process similar to osmosis in the right environment.

      

Methods

Procedure: (PART I - work in groups of 4)

        **PRE-LAB: Students will make the various sucrose solutions beforehand.**

1.     Obtain six, ~20c cm strips of pre-soaked dialysis tubing.

2.     Tie off one end of each piece with `twisty ties’ to form 6 bags.

3.     Pour 25 mL of each of the following sucrose solutions into separate bags:

a.     0.0M sucrose—distilled water

b.     0.2 M sucrose

c.      0.4M sucrose

d.     0.6M sucrose

e.     0.8M sucrose

f.      1.0M sucrose

4.     Remove excess air from each bag and tie off with `twisty ties’.

5.     Rinse each bag under tap water to remove sucrose from the string and outside surfaces

6.     Carefully blot the outside of each bag and record the initial mass of each bag in Table 1.1.

7.     Place each bag in one of three 250 mL beakers (or cup if that is the only option) and fill with distilled (or tap if that is the only option) water to the 200 mL mark. Label beaker with appropriate information.

8.     Let stand for 20 minutes

9.     At the end of 20 minutes, remove the bags and carefully blot each.

10. Determine the mass and record in Table 1.1 for the solutions you were assigned.

11. Record data of percent change in mass in Table 1.2 (both in your tables and also on the class computer).

Procedure: (PART II – work in groups of 4)

**PRE-LAB: Students will make the various sucrose solutions and potato cores beforehand.**

1.     Obtain 100 mL of each of the sucrose solutions and pour each solution into a separate, labeled 250 mL beaker (or cup if that is the option).

2.     Use a cork borer (approximately 5mm in inner diameter) to cut 24 potato cylinders. Cut each cylinder to segments 3 cm in length. Remove any skin found on the cylinders.

3.     Determine the mass of 4 of the cylinders together, and record in Table 2.1. Put these 4 cylinders into one of your sucrose solutions.

4.     Do the same for 4 other cylinders and place in your second sucrose solution.

5.     Do the same for the remaining cylinders (in groups of 4) and place n the remaining sucrose solutions.

6.     Cover the beakers with plastic wrap.

7.     Let stand overnight.

8.     The next day, record the temperature of the sucrose solutions in Table 2.1.

9.     Remove the cores from one of the beakers, blot them gently on paper towel and determine their combined mass. Do the same for your two other beakers.

10. Record the final masses and calculate percent change in Table 2.1.

11. Record data of percent change in mass in Table 2.2 (both in your tables and also on the class computer).

Results

Part I - Membrane Demonstration

Contents of Beaker	Initial Mass	Final Mass	Mass Difference	% Change in Mass
0.0M sucrose	3.82 g	3.89	.07	1.80%
0.2M sucrose	5.25 g	6.09	.84	16.0%
0.4M sucrose	3.14 g	3.2g	.06 g	1.88%
0.6M sucrose	4.58 g	5.03 g	.45 g	8.95%
0.8M sucrose	1.98 g	1.70 g	-.28 g	14.14% decrease
1.0M sucrose	4.46 g	4.15 g	-.31 g	6.95% decrease

Part II - Potato Demonstration

Contents of Beaker	Initial Potato Mass	Temperature	Final Potato Mass	Mass difference	% Mass Change
0.0M sucrose	7.17 g	76F	7.14 g	-.03 g	.41% decrease
0.2M sucrose	10g	76F	5.96 g	-4.04 g	40.4% decrease
0.4M sucrose	11g	76F	11.89 g	.89 g	7.49%
0.6M sucrose	10.5g	76F	5.5 g	-5.0 g	47.62% decrease
0.8 M sucrose	15.00 g	76F	10.35 g	-4.65	31% decrease
1.0 M sucrose	10.20 g	76F	7.45 g	-2.75	26.96% decrease

Discussion

The result of the lab after

The lack of any observed difference in mean circumference between chewed and not chewed trees does not agree with our hypothesis that beavers will prefer smaller trees to larger ones. Our hypothesis was based on the idea that branches from smaller trees will require less energy to cut and haul than those from larger trees. Our finding is in accordance with other studies (Schoener 1979), which have suggested that the value of all trees should decrease with distance from the water but that beavers would benefit from choosing large branches from large trees at all distances. This would explain why there was no significant difference in circumference between chewed and not-chewed trees.

This lab gave us the opportunity to observe how a specific mammal selects foods that maximize energy gains in accordance with the optimal foraging theory. Although beavers adhere to the optimal foraging theory, without additional information on relative nutritional value of tree species and the time and energy costs of cutting certain tree species, no optimal diet predictions may be made. Other information is also needed about predatory risk and its role in food selection. Also, due to the large number of students taking samples in the field, there may have been errors which may have affected the accuracy and precision of our measurements. In order to corroborate our findings, we suggest that this study be repeated by others.

Conclusion

The purpose of this lab was to learn about diffusion and osmosis within potatoes and dialysis tubes. We were able to see that the potato cells diffused the water through osmosis from within, and the water outside of the tube diffused water, and entered the tube through osmosis. We also learned that the results aren’t always going to match the original theory. For instance, one of our tubes lost mass in the second trial, which could have been a result of a leaking tube, or incorrect initial measurements. For the most part, what was expected occured.

Nishiura, P. J. (n.d.). Lecture Outline Biology 4 Section FV. Retrieved 10 8, 2013, from Brooklyn College City University of New York: http://academic.brooklyn.cuny.edu/biology/bio4fv/page/semes.htm