Thursday, September 24, 2009
Is this the coolest wildlife video ever? From Kruger National Park in South Africa
One of my former students sent me a link to this video. It seems like almost everything that we have talked about so far is going on in this video. The highlight of my biology life was visiting Kruger Park when I was about 13 (how sad to peak so young). I saw lots of amazing animals, but I didn't see anything like this. Enjoy! Make sure you watch all the way through- it just keeps getting better.
http://www.youtube.com/watch?v=LU8DDYz68kM
Community Ecology- The Portal Experiment
Here are some photos from the research site in Portal, Arizona. For more information about the research project at Portal you can look at their website at
http://www.biology.usu.edu/labsites/ernestlab/portal/index.html
Expected Learning Outcomes
By the end of this course a fully engaged student should be able to
- distinguish between direct and indirect, positive and negative effects
- describe the experiemental design that Dr. Brown and his colleagues used to study exploitative competition between desert rats and rodents
- discuss the "search the the missing indirect positive effect of rodents on ants" and how that dilema was solved
-discuss why and how the outcome of studies of interactions betwen organisms can vary over time
- discuss the way that the ecological community responded when they learned the importance of long term studies
- discuss how indirect interactions influence my facvorite phrase "the world is complicated"
Community Ecology
Suggested Readings
Community Ecology- http://www.eoearth.org/article/Community_ecology
Competition- http://www.eoearth.org/article/Competition
Interspecific Competition- http://www.eoearth.org/article/Interspecific_competition
Exploitative Competition- http://www.eoearth.org/article/Exploitative_competition
Predation- http://www.eoearth.org/article/Predation
Mutualism- http://www.eoearth.org/article/Mutualism
Expected Learning Outcomes
By the end of this course a fully engaged student should be able to
- define competition, exploitative competition and interference competition
- identify and explain examples of exploitative and interference competition from a variety of environments
- define predation (narrow and broad sense), herbivory, and parasitms
- identify and explain examples of predation, herbivory, and parasitism from a variety of environments
- identify examples of morphological and behavioral adaptations that animals have to help capture their food
- identify examples of morphological, biochemical, or behavioral adaptations that animals have to protect them from predators
- identify and explain examples of mutualisms from a variety of habitats
- define a keystone species and an ecosystem engineer and provide examples of each.
This is cool!
Here are some photos that someone forwarded to me. This has nothing to do with the class other than to show how fantasitcally cool biology can be. Enjoy
Mass Migration of Rays
Looking like giant leaves floating in the sea, thousands of Golden Rays are seen here gathering off the coast of Mexico . The spectacular scene was captured as the magnificent creatures made one of their biannual mass migrations to more agreeable waters.
Gliding silently beneath the waves, they turned vast areas of blue water to gold off the northern tip of the Yucatan Peninsula . Sandra Critelli, an amateur photographer, stumbled across the phenomenon while looking for whale sharks.
She said: 'It was an unreal image, very difficult to describe. The surface of the water was covered by warm and different shades of gold and looked like a bed of autumn leaves gently moved by the wind.
'It's hard to say exactly how many there were, but in the range of a few thousand'
'We were surrounded by them without seeing the edge of the school and we could see many under the water surface too. I feel very fortunate I was there in the right place at the right time to experience nature at its best'
Measuring up to 7ft (2.1 meters) from wing-tip to wing-tip, Golden rays are also more prosaically known as cow nose rays.
They have long, pointed pectoral fins that separate into two lobes in front of their high-domed heads and give them a cow-like appearance. Despite having poisonous stingers, they are known to be shy and non-threatening when in large schools.
The population in the Gulf of Mexico migrates, in schools of as many as 10,000, clockwise from western Florida to the Yucatan .
Thursday, September 17, 2009
Writing Assignment #2
During Friday's Lunch Discussion I will introduce the idea that people are consuming resources and creating wastes in an unsustainable manner.
Ecological Footprint
An "ecological footprint" is way of quantifying how much or the earth's surface is required to support our lifestyle. Not surprisingly because of our lifestyles, citizens in the United States of America have a much larger ecological footprint than citizens of most other nations on earth.
There are a number of "footprint caluclators" on the web that can allow you to calculate your personal ecological footprint. Unfortunately, because most of you are currently living in dormatories, it is difficult to calculate your footprint using these calculators, so I won't ask you to do the calculations for this assignment. It is kind of fun to play around with these calculators to examine how changing your lifestyle can affect your ecological footprint.
Readings
To learn more about ecological footprints please read-
Ecological Footprint- http://www.eoearth.org/article/Ecological_footprint
Ecological Footprint Quiz FAQ- http://www.earthday.net/footprintfaq
Footprint Basics- Overwiew- Global Footprint Network (there is a lot of good info on this site).
http://www.footprintnetwork.org/en/index.php/GFN/page/footprint_basics_overview/
Writing Assignment #2
What is an ecological footprint? How and why do ecological footprints vary among nations around the world? What do you think about the ecological footprints of the average citizens of the United States of America?
Length- 2 pages minimun, 3 pages maximum
Due Date (I am sorry that I left this out initially)
Rough draft due Friday September 25th
Workshop- Monday September 28th
Final Draft due- Friday October 2nd
Please let me know if you have any questions about the assignment
Tuesday, September 15, 2009
Lunch Discussion- Friday September 18th
Remember that we will meet in the lounge in Knapp Hall at noon on Friday September 18, so that we can participate in the Honors College weekly Lunch Discussion (don't worry, we will be back to the classroom where we can keep on drawing graphs on Monday).
The discussion will be led by a brilliant, articulate, inspirational, and devilishly handsome faculty member, so it should be the highlight of your week (perhaps your semester).
Topic: "Our relationship to the natural world."
Read: "We are all Madoffs: Our relationship to the natural world is a Ponzi scheme.” from the The Chronicle of Higher Education
http://chronicle.com/article/We-Are-All-Madoffs/48182/?sid=at&utm_source=at&utm_medium=en.
Lunch: Food and drink will be provided
Please come ready to discuss.
Remember to bring your papers!!!
Wednesday, September 9, 2009
Human Population Growth
I have spent a lot of time telling you that exponential growth is an unrealistic model of population growth. Interestingly, human populations have experienced exponential-like growth. How can this be?
What makes humans different from other species?
In other species per capita birth rates and per capita deaths rates are density dependent. However, as human populations have increased there has been no corresponding decline in per rates or increase in death rates. What makes humans different from other species?
Humans have the ability to alter their environment so that they can avoid the density dependent effects on birth and death rates. 1) Humans have increased food production by improvements in agriculture (e.g., irrigation, fertilization, mechanized farming, genetically improved crops). 2) Humans have been able to decrease death rates by improvements in medicine and public health (things as simple as not pooping in the water you drink helps a lot!). 3) Humans have elimnated most human predators (ocassionally, someone gets killed by a shark or a mountain lion).
Where is human population growth occuring?
The rates of human population growth are not the same in all regions. Today, human populations are increasing in size much faster in developing countries (e.g., Mexico, other countries in Central America, Africa, and Southeast Asia) than they are in developed countries (e.g, USA, Canda, Western Europe). The figure at the top of this post shows the patterns of population growth in developed and developing nations.
Thus we see that populations are increasing most rapidly in the countries that are least able to deal with a rapidly increasing population. See "Population Challenges-The Basics" that can be downloaded from the Population Institute's website.
http://www.populationinstitute.org/population-issues/index.php
Human Population Growth Proble?
There is a great deal of debate about whether increasing human populations are a problem or not, and if they are what should be done about it. Unfortunately, we don't have time to discuss this issue in very much detail in class. My personal opinion is that we have too many people consuming too many resources and the last thing that we need are billions more people living on the planet. This is an issue that I am always intersted in talking more about if you would like to chat.
Further Reading
Also see the article "Human Population Explostion" from the EoE.
http://www.eoearth.org/article/Human_population_explosion
Human population growth over history - http://www.globalchange.umich.edu/globalchange2/current/lectures/human_pop/human_pop.html
Really Cool Video
Here is a link to a YouTube video on "World Population" The first minute and a half or so is a little boring, so you can skip over it if you wish. However, I think the animation showing when and where human population growth has been occuring is really cool.
http://www.youtube.com/watch?v=4BbkQiQyaYc
Expected Learning Outcomes
By the end of this course a fully engaged student should be able to
- describe patterns of human population growth in developed and developing nations
- discuss some reasons why the pattern of population growth in humans is so different from that in other species
- describe the demographic transition
- discuss their own personal view of human population growth.
Friday, September 4, 2009
Quiz Yourself- Population Ecology
Practice Problems
1) In a population of 50 tigers, in one year 10 tigers are born and 20 tigers die. What is B, D, dN/dt, b, d, r?
2) Draw the graph that plots how the population size changes over time in exponential growth.
3) Define the carrying capacity.
4) Describe in words how the population size varies over time in logistic growth when the initial population size is much smaller than the carrying capacity.
5) The Gray Angelfish (shown at the top of the post) is one of my favorite species living on coral reefs in the Caribbean Sea. This species feeds on sponges and is prey for larger reef fishes such as baracudas. Why is the reef not covered with Gray Angelfish?
Population Ecology
Here is a brief introduction to some of the important parameters that we will need to understand to be able to study population ecology. For each of the parameters it is important that you know (1) the name of the parameter, (2) the algebraic symbol used to represent the parameter, (3) the units of measurement for the parameter, (4) how to calculate the parameter, and (5) how to describe (in words) what a particular value of that parameter means.
It is probably easiest for me to introduce these concepts using an example.
Imagine that in a population of 100 elephants that in one year 10 elephants are born and 5 elephants die.
1) Population Size (N) units- individuals. Measures the number of individuals in a population.
N = 100 individuals
In this population, there are 100 elephants.
2) Population Birth Rate (B) units- number of births per time. Measures the number of births per time that occur in a population.
B = 10 births/year
In this population, each year there are 10 births.
3) Population Death Rate (D) units- number of deaths per time. Measures the number of deaths per time that occur in a population.
D = 5 deaths/year
In this population, each year there are 5 deaths.
4) Population Growth Rate (dN/dt) units- number of idividuals per time. Measures the rate of change of the population size.
dN/dt = B - D
dN/dt = 10 births/year - 5 deaths/year = 5 individuals/year
In this population, the population size increases by 5 individuals each year.
5) Per Capita Birth Rate (b) units- births per time per individual. Measures the number of births per time averaged across all members of the population.
b = B/N
b = (10 births/year)/100 individuals = 0.10 births/year/individual
In this population, each year 0.10 babies are born for each individual in the population.
6) Per Capita Death Rate (d) units - deaths per time per individual. Measures the number of deaths per time averaged across all members of the population.
d = D/N
d = (5 deaths/year)/100 individuals = 0.05 deaths/year/individual
In this population, each year 0.005 individuals die for each individual in the population.
7) Per Capita Growth Rate (r) units = individuals/time/individual. Measure the rate of change in population size averaged across all individuals. The per capita growth rate can be calcuated two ways.
a) r = b - d
r = 0.10 births/year/individual - 0.05 deaths/year/individual = 0.05 ind/year/ind
b) r = (dN/dt)/N
r = (5 individuals/year)/100 individuals = 0.05 individuals/year/individual
In this population, each year 0.05 individuals are added for each individual in the population.
Practice Problem
In a population of 50 tigers, in one year 10 tigers are born and 20 tigers die. What is B, D, dN/dt, b, d, r?
Readings
Population- http://www.eoearth.org/article/Population
Population ecology- http://www.eoearth.org/article/Population_ecology
Population growth rate- http://www.eoearth.org/article/Population_growth_rate
Exponential growth- http://www.eoearth.org/article/Exponential_growth
Logistic growth- http://www.eoearth.org/article/Logistic_growth
Carrying capacity- http://www.eoearth.org/article/Carrying_capacity
Expected Learning Outomes
By the end of this course a fully engaged student should be able to
- define and calculate the value of basic population ecology parameters
- draw and interpret the following graphs
a) how population size changes over time in exponential growth
b) how population size changes over time in logistic growth
- explain why exponential growth is an unrealistic pattern of growth for most species
- define and explain the carrying capacity
- discuss the factors that regulate population size, be able to distinguish between density dependent and density independent factors that regulate population growth and give examples
Critical Thinking Rubric
This table lists characteristics of work done by individuals with different levels of critical thinking skills. Hopefully, this information will help you to (1) write your own papers and (2) critically analyze papers written by your fellow students.
Note: If you double click on the table it will get larger so it is easier to read.
Writing Assignment #1
The web post "Adaptations to desert environments" on this site examines how natural selection has molded the morphology, physiology, and behvior of organisms living in arid environments.
Writing Assignment #1
Imagine that you have been assigned the job of developing material that can be used in the visitors center of a desert nature park. The purpose of this information is to teach park visitors about the organisms that live in deserts. You should think of your audience as being reasonably intelligent non-scientists (e.g., your roommate, your grandma, etc). Make sure that your material addresses the following points.
1) identify and discus the unique challenges associated with living in arid environments
2) explain adaptations of animals and plants for water uptake and water conservation
3) explain adaptations of animals and plants for dealing with high temperatures
Format: Maximum length is three pages. Use Times New Roman 12 point font, black color. You should put your name, date, and the title of your essay at the top of the page (there is no need for a "cover sheet".)
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