Upcoming SlideShare
×

# How dense is your population

467 views

Published on

Published in: Technology
0 Likes
Statistics
Notes
• Full Name
Comment goes here.

Are you sure you want to Yes No
• Be the first to comment

• Be the first to like this

Views
Total views
467
On SlideShare
0
From Embeds
0
Number of Embeds
2
Actions
Shares
0
5
0
Likes
0
Embeds 0
No embeds

No notes for slide

### How dense is your population

1. 1. How dense is your population? 8SCIENCE: Tues. Oct. 26
2. 2. Population density REVIEW: What are the characteristics of a population? (3) – Population Size – Population Spacing – Population Density - What is population density? - Number of individual organisms living in a certain area
3. 3. Population density examples • # individuals = population density area 1) If 2500 grasshoppers live in an area of 1 km², what is the population density? – 2500 grasshoppers/km² 2) If there are 23 students in our class, and the area of this room is 46km², what is the population density? – 2 students/km² 3) If 15 cows live in an area of 60km², what is the population density? – 4 cows/km²
4. 4. Population density activity: Quick activity: your group will be given a garbage bag and ruler 1) Take the garbage bag at your table and measure the length and width - What is the area of the bag? 2) Place it on the floor and all members in your group should try to stand on it – both feet should be on the bag. - How many people are in your group? What is the population density on the bag? 3) Now take the garbage bag and fold in half – what is the area? - Can all of your group stand on the bag? - What is the new population density? 4) Repeat step 3 by folding the bag one more time. - Why wasn’t everyone able to stand on the bag? - What were you competing for?
5. 5. More characteristics of populations REVIEW: • What do living things need to grow and reproduce? – Can these populations grow forever? – Why not? LIMITING FACTORS • Another characteristic of populations is called carrying capacity • Imagine a population of rabbits increases each year. Is there a limit to the supply of resources in that environment? • YES: after some time the environment will not have enough resources for the rabbits to survive or reproduce and the population will stop increasing
6. 6. Carrying Capacity • (17– 9 pg. 490) – This means the environment has reached the CARRYING CAPACITY – Carrying capacity is the largest number of individuals an environment can support and keep healthy for a period of time – What do you think happens when the population becomes higher than the carrying capacity?
7. 7. Human growth • What are some limiting factors to human population growth? – Water – Food – Living space – Pollution – Disease • To measure our human impact on nature, we measure our ecological footprint (eco-footprint)
8. 8. Eco-footprint • How do we impact the earth and create our footprint? – Food – Energy use – Transportation • If everyone on Earth lived the way the AVERAGE person in North America did, we would need 3.8 Earths to support all of the people