13. Human impacts

TO WHAT EXTENT SHOULD PEOPLE INTERFERE WITH INTERACTIONS IN ECOSYSTEMS TO IMPROVE HUMAN LIFE?

Outcomes:

• Respond to images that reflect the impact of humans on ecosystems

  • Discuss a debatable question to reach a group conclusion

  • Select an option to take action and complete the template to demonstrate and explain the action you will take.

The Statement of Inquiry says 'ecosystems can be in balance when the species sharing their habitat have interconnected functions and roles'. So it is important to reflect and discuss the role of humans in the interactions between organisms and the balance of ecosystems.

We can also consider farming as another way in which humans influence interactions between animals for human benefit. For example, humans manipulate the reproduction of cows, chickens, pigs and fish in order to meet the demand for meat products. In addition, some farmers use pesticides in order to poison or kill the insects or other 'pests', such as mice or insects, that feed on or damage their crops.

Other organisms in the food web may then eat these poisoned insects or rodents, and the toxins are passed along, causing deaths higher up the trophic levels. Farmers say they do this in order to produce more crops and to keep supplies up and prices down.

Organisms at different trophic levels in a food web, such as these baby bass and bees, are affected by the use of pesticides and other chemicals that farmers use to manipulate the growth of their crops.

DISCUSS

Using these examples, as well as those mentioned in the previous lessons, such as hunting, discuss with your partner and your class your opinion in response to the debatable question:

"To what extent should people interfere with or influence the interactions between different species in an ecosystem in order to try to extend and improve human life?"

Remember to use scientific explanations about the interactions of living things in order to support your point of view.

! Take action

AtL

• Transfer skills: Combine knowledge, understanding and skills to create products or solutions.

! Consider ways in which your daily actions affect the interactions between living things. Perhaps some products you buy and use come from companies that disrupt the interactions between the organisms that live in the ecosystems surrounding their factories. Or maybe the impact on organisms comes after you throw the product away.

! List some things that you use regularly, and research on the science behind how those items are produced and what happens after we dispose of them.

! Explain the ways in which the production or disposal of these products may interfere with natural interactions that occur within an ecosystem and keep it in balance.

• Consider these questions: which products can we reduce or stop using? Is there a more eco-friendly product from a more eco-friendly company? Are there alternatives for disposal that are now possible due to scientific development?

! Explain the ways in which scientific knowledge and understanding of interactions in an ecosystem can be used and applied to provide suggestions or alternatives for producing and disposing of products in a more eco-friendly way.

! Discuss and evaluate some of these science-based suggestions or alternatives for producing and disposing of more eco-friendly products:

• • How might cultural, economic, environmental,, ethical, moral, political or social factors interact with the implementation or impacts of these science-based suggestions and alternatives.

! Present your findings to raise awareness of the suggestions, and alternatives. Imagine the difference if more people bought and used products that are less disruptive to the balance of healthy ecosystems.

! Remember to consistently apply scientific language so you can communicate your understanding clearly and precisely and document all of your sources completely.

Assessment opportunities

• • This activity can be assessed using Criterion A: Knowing and understanding and Criterion D: reflecting on the impacts of science.

Citations

Rowe, Dr. Edwin. Dr. Edwin Rowe and a Young Patient . www.galapagos.to/TEXTS/NOT-50.HTM.

Roy, Tui de. Galapagos Invasive Species. www.hear.org/galapagos/invasives/topics/management/vertebrates/projects/pi.htm.

“Thepetitionsite.com.” Thepetitionsite.com, www.thepetitionsite.com/takeaction/401/373/567/.