Population+Collaboration

Populations 1. Define a population? Give an example. What does a population study focus on? - Kamberlyn population: a group of organisms of the same species that live in a specific geographical area and interbreed.

example: an example of population would be a California poppies that grow in California. 2. Describe the procedure for estimating population sizes from the book. Describe the mark-recapture method and give an example of how it could be used(Will have to go to the Web for this one!). Sharice __**Sharice Nixon**__ A population size is the number of individuals a population can contain. If you have a population with organism's like plants you can determine the population size by counting them. Other situations scientist have to come up with an estimate or guess of how many individuals are in a larger area. What they do is count a small section of the area and multiply to get their answer of how many individuals are there. -The mark-recapture method is commonly used in ecology to estimate population size.
 * Aleéja Barnes**

3. What is population density? Give a formula. Give an example.
 * Population density measures how crowded a population is. Population density = number of organisms per area. Example: the population density of humans in the United States is about 30 people per square kilometer.

4. What is dispersion? Describe and find pictures of random, uniform and clumped dispersion.
 * Dispersion is the spatial distribution of individuals within the population.
 * Random distribution is when each individual's location is independent of the locations of other individuals in the population.




 * Clumped distribution is when individuals are clumped together. They occur when resources such as food or living spaces are clumped. They also may occur because of the animal's social behavior, such as when animals gather into herds of flocks.




 * Uniform distribution is when individuals are separated by a fairly consistent distance. This may result from social behavior in which individuals within the habitat stay as far away from each other as possible.

5. Define birth rate, death rate and life expectancy for a population. Rett Birth rate - The ratio of total live births to total population in a specified community or area over a specified period of time. The birthrate is often expressed as the number of live births per 1,000 of the population per year. Death rate - The ratio of total deaths to total population in a specified community or area over a specified period of time. The death rate is often expressed as the number of deaths per 1,000 of the population per year. Life expectancy for a population - The number of years that an individual is expected to live as determined by statistics.

6. Define an age structure diagram. Find pictures of age structure diagram and write if each population is growing, getting smaller or showing zero growth. May need to go the Web for this one, the book does not give much information. Rett Age structure diagram - A diagram for representing the age distribution of a population. It is really a histogram in which age is plotted vertically and frequency, or relative frequency, is plotted horizontally. Often drawn as a back-to-back pyramid with one side for males and the other side for females. Paired pyramids can be used to compare two populations.



7. Describe the three types of survivorship curves. Give an example of organisms for each. Find a labeled picture similar to the one in the book. Sam
 * There are Type one who has a steady horizontal slope which drops off at the end, Type two which has a constant decend, and Type three which drops dramitcally and then has a steady line till death. A good example for type one is a human, a good example for type two is a bird, and a good example for type three is a fish

8. Define growth rate. What four processes determine a populations growth rate. What is the formula for growth rate? Sam the amount by which a population’s size changes in a given time. birth, death, emigration, and immigration. birth rate - death rate = growth rate 9. Define exponential growth. What shape does the graph take? Insert a picture of a line graph showing exponential growth. Meme Meme Hand

10. Does exponential growth model apply for all populations? Define and give an example of limiting factors. Meme 10.No. The exponential growth model does not apply for all populations. Limiting factors are environmental factors that prevent an organism or population from reaching its full potential of distribution or activity. For example, there might not be enough food for cardinals in the park so they can't reach their full population potential.
 * 1) Exponential growth is the population growth in which a constant unlimited growth rate results in geometric increases in a population size. The graph curves up and to the right.[[image:http://t3.gstatic.com/images?q=tbn:ANd9GcQFwI9e-U_J97SvBurn_ONlctzDekfed74UmQGS8x5mKTD-Nak&t=1&usg=__TmZR35ITsfLK-lRwdFNbfHpZav8= width="256" height="192"]]

**11. What does the logistics growth model look like(find a picture)? What letter is used to describe logistics growth. Define carrying capacity. What is the symbol for carrying capacity? Shea ** A logistics growth model is a graph with a line usually cuving upwards. The population is on the y-axis and the time interval is on the x-axis. The letters used to describe is t and Nt-t. Carrying capacity is the largest number of indivisuals of a particular species that can survive over long periods of time in a given environment. The symbol is K.

**12. Define density independent factors and density dependent factors. Give several examples of each. May need to go to the Web for more examples. ** Density independent factors is a factor that affects the size of a population independent or regardless of the population density. Some examples are climate and catashrophe, forest fires, and pollutants. Density dependent factors is a factor whose effecsts on the size or growth of population vary with the population density. Some examples are predation, disease, and competition, avalability of food, and parasitism. 13. Describe the predator prey model on pg 388-may need to use the Web. Find this graph on the Internet and insert. Describe what is happening to the lynx population as the hare population increases. What happens to the hare population as the lynx population increases? What type of population regulation is this an example of? Look at question 12 for the two types. Sarah The figure on page 388(also above) shows that each animal controls the other animals cycle. When the hares population increases, so does the lynx, because it has more to feed on. Same with when the hares population decreases, so will the lynx. This would be a density- dependent factor because it includes resource limitation. ~Sarah Wells 14. Why is it so bad to have small populations of organisms? What is inbreeding? Why is it a bad thing? Griff 15. Describe the bottleneck effect. Find a picture to represent the bottleneck effect. Griff

By: Grif Rutherford 14.Why is it so bad to have small populations of organisms? What is inbreeding? Why is it a bad thing? **Because the less of an organism, the more chance it has at going extinct. The breeding of closely related organisms, they are closer related than the average populations (ex: sibling/sibling, mother/son, father/daughter).****The limited gene-pool caused by continued inbreeding means that deleterious genes become widespread and the breed loses vigor. They also cause a syndrome or disease (ex: in humans may be down syndrome)**

15. Describe the bottleneck effect. Find a picture to represent the bottleneck effect. **Bottleneck effect refers to the reduction of a population’s gene pool and the accompanying changes in gene frequency produced when a few members survive the widespread elimination of a species.** **As you can see, there are less yellow in the next generation then in the parent population.**

16. Describe the history of the human population. Include Include a graph. Akeem History of Human Population- human populations since the Black Death in the 1400's has said to be increasing over 1.8 percent each year. Which was first seen in the 1950's but then in longer periods in the 1960's and 1970's. It peaked 2.2 percent in 1963 but declined back to 1.10 percent in 2009. Scientists Observations predict that the population should be 8-10.5 billion in the years 2040-2050. 17. What are the characteristics of developing nations? Give examples. Tyia =Jasmine Dixson =

18. Describe the Industrial Revoluluton. How did this effect the human population. How is our population growing today? Jasmine

 * The industrial Revolution was a time in the 18th and 19th century that major changes began to occur. Changes such as: agriculture, manufacturing, mining, transportation and technology.
 * This new change would soon change the human population from 300 million people to 700 million people. Due to the new technology and medicines it could keep people stay alive longer, which made the population grow.
 * The more the technology is growing the more people can be more aware of diseases and natural causing deaths, which makes the population grow wider/larger.

19. How many people are on earth? What is the growth rate for the human population? How many people are expected to be on earth by the end of your life time? Jasmine
20. What is the carrying capacity for earth? Do you think that we will ever reach it? Will need to research this one on the Web. There are many proposed answers for this one. Rachael
 * <span style="display: block; font-family: Times New Roman,serif;">There are //<span style="display: block; font-family: Times New Roman,serif;">6,697,254,041 //<span style="display: block; font-family: Times New Roman,serif;">people on earth.
 * <span style="display: block; font-family: Times New Roman,serif;">Annual Births have reduced to 140 million from 173 million
 * <span style="display: block; font-family: Times New Roman,serif;">The population is expected to reach between 8 and 10.5 billion between the years 2040-2050.

The average Carrying Carrying capacity of the earth is estimated around 50 billion, which is ten times more than the average population right now.
==== I do not believe we will ever reach the carrying capacity because as many people there are being born, there are also people who die. And also because the life cycle is not very long depending on the life span of living things. ====  21. What are the characteristics of developed nations. Give examples. Rachael

What are some examples of a developed nation? Rachael Willis
 * High literacy rate- many people are able to read and write.
 * low infant mortality rate- less children and babies are dying from disease, starvation, etc.
 * high energy consumption- country's are using energy for electricity, transportation, etc.
 * longer life expectancy- people are living longer.
 * high income per capita- people are having higher pay with their jobs.
 * high human development index- there is lots of construction for developing homes, buildings, etc.

22. What is the demographic transition model? Include a picture. McKenna **Demographic Transition Model:** The Demographic transition model is a model used to represent the process of explaining the transformation of countries from high birth and death rates to low birth and death rates as a country develops from a pre-industrial to an industrialized economic system. Basically, the demographic transition model shows how human populations have developed and stopped growing over time.

23. Answer question 6 from pg 392. 24. Answer question 7 from pg 392. 25. Answer question 8 from pg 392.