Interdependence & Adaptation – High Lawn’s 6D

To see 6D's original post...

Creative Science

Hello 6D,

The chatterboxes look brilliant. I must say I have never thought of using them this way but it's a great way of reinforcing ideas and facts.

When at university, one of my majors was in zoology, the study of animals. We were often looking at the interdependence and adaptations in species so your post started me thinking and that can mean an extended comment is on the way.


This is an important issue when we look at ecosystems, especially when we look at the way human activity can interfere with systems. What may seem an unimportant plant or animal species may be an essential part of the ecosystem. If it disappears, there may be a flow on effect where more species die out. Here’s a hypothetical example...

Mosquitoes can be a problem so some have proposed spraying to kill them off. Now, suppose there are tadpoles that rely on their larvae for food and spiders that rely on capturing mosquitoes in their web. Further along the food chain, there are snakes that rely on the frogs as food and small birds relying on mosquitoes. Higher still in the food chain, there are birds relying on capturing snakes and small insect eating birds. You see, the interdependence of these species mean the loss of mosquitoes can also cause the loss of other species. Here is a clip on food chains, food webs and energy pyramids…

This is why modern societies carry out environmental impact statements. Scientists hope to be able to identify the harm to species and the environment by the changes proposed. It was a study like this that changed the plans for the development of tennis courts for Sydney’s 2000 Olympic Games.

The green and golden bell frog was rare in Sydney and had disappeared from as much as 90% of its original range but a colony had been found in an old brickpit in the Olympic district. The discovery meant changing the plans so the frog could be protected. They are now thriving in this small area. A link about the frog…

Wikipedia frog information:

 A video of the Olympic Park Brickpit Walk:


Have you ever heard someone say no two people are exactly alike, even identical twins? It’s these differences that can become important. Two animals of the same species may have slight differences. One may be a little faster or better able to catch prey. When times are good and there is plenty of food, there may be no advantage but if there is an increase in predators or less food, the faster, better hunter is more likely to survive and pass on their advantage to their young.

One of my favourite examples is a moth known as the peppered moth in England. They came in two main forms, white-bodied and black-bodied.

The light-bodied form was the most common because its dappled colour better blended into the lichens and bark on trees so fewer were taken by birds but the Industrial Revolution changed this when more and more soot from burning coal settled of everything. The black-bodied forms became more common because the darker moths were then harder to see. Now, with better environmental standards, the white-bodied moth has again become more common.

Wikipedia peppered moth information...

 A video about the peppered moth


Schools and students have permission to use this graphic for non-commercial, educational purposes.

There's an old saying, "Extinction is forever."

It's up to us to try to protect what we can.


Teacher (retired), N.S.W., Australia

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