When planning for teaching in your classroom, it can be useful to see where a sequence fits into the larger picture of science. This unit is anchored to the Science Understanding core concepts for Biological sciences.

• A diverse range of living things have evolved on Earth over hundreds of millions of years; this process is ongoing.
• The form and features of living things are related to the functions that their body systems perform.

Students have experienced these core concepts before by examining the characteristics of living and non-living things and the differences between the life cycles of plants and animals (Year 3). In Year 5, these core concepts involve explaining how particular structural features and behaviours of living things enable their survival in specific habitats.

This core concept is linked to the key science ideas:

• Function can be predicted by analysis of form/structure (Form and function).
• Generalisations about relationships between system components can be made (Systems).
• Classification can be used to inform predictions about properties and behaviours (Patterns, order and organisation).
• Models can be used to investigate relationships between components of systems (Systems).

When your students next progress through this core concept, they will investigate the physical conditions of a habitat and analyse how the growth and survival of living things is affected by changing conditions (Year 6).

Students might believe that individuals adapt to their environment in their lifetime and pass this ability to their offspring.

It is true that certain animals can change their behaviours in new situations and teach this to their offspring and any animals in their “social group”. For example, many sulfur-crested cockatoos living in suburban areas have learned how to open rubbish bins and remove items in search of food. This is a behaviour that has allowed that particular bird, or flock of birds, to adapt to living in an urban environment that has fewer available natural food sources. Sulfur-crested cockatoos living in an environment surrounded by their natural food sources are unlikely to know how to open a rubbish bin, because they will not have needed to develop that skill.

An adaptation, however, is not something that happens at an individual level, but rather something that occurs when the survival of a whole population of a plant or animal is affected. Adaptations can affect an animal’s instinctive behaviours, such as living in groups or migrating at specific times of the year, or their structural features, such as having longer legs, smaller leaves, or camouflage.

For example, sulfur-crested cockatoos often eat in groups, with some working as lookouts, emitting a piercing warning screech if a predator is spotted. They have a powerful hooked beak to help them crack open nuts, seeds, and fruits. Sulfur-crested cockatoos living in both urban and more natural environments exhibit these behaviours and features. They have enabled the survival of the species over time.

Students might believe that animals choose their adaptations based on their environment. However, adaptations are not a conscious choice by individuals. For example, giraffes do not choose to have a long neck. It is the success of the giraffe parents with the structural features and behaviours that enable them to reach food high in a tree that allows them to survive to have offspring that also have long necks.

Students might think it is easy for animals to change habitats if the one they are in is no longer providing what they need, for example, if food becomes unavailable. While this is the reason some animals migrate during lean seasons, it is dependent on the new habitat being able to supply all the needs of the animal. For example, the bogong moth migrates thousands of kilometres at the start of each summer to the cooler caves in Victoria and NSW’s higher regions. This means they need appropriate food supplies during the journey. They rely on the nectar of particular plants and have moth parts that allow them to harvest this from particular flowers. If those plants are not present, it can make the journey more difficult.

In this sequence, students explore the structural adaptations of many plant and animal species to identify how these features support the survival of the species. In Lesson 5, in particular, they look at a case study of the peppered moth to help form an understanding that adaptation occurs across the entire species, and not simply to individual animals.

By simply looking at animals or plants, you can often identify structural features or behaviours that are common across a population/group and the probable function of this feature. For example, some animals have large eyes that allow them to see well in darkness and some populations of plants have waxy leaves that help minimise water loss (although it should be noted that these are not the only possible reasons an animal might have large eyes, or a plant might have waxy leaves).

These features, which are important to the survival of animal or plant populations in their native environment, are called “adaptations”.

Adaptations evolve by means of natural selection. If the conditions in the environment favour particular traits, such as larger eyes that help to see food and predators at night, or waxy leaves that help slow dehydration in water-poor environments, then the individuals who have these traits are more likely to survive and reproduce. If offspring inherit these traits, then future generations are more likely to have larger eyes and waxier leaves. 

Generally, scientific adaptations are identified at a population level; one individual with a difference is a mutant who might survive better in the environment. If the individual’s offspring inherit the trait and also survive better in the environment, then the mutation may gradually become “normal” in the population and be considered an adaptation.

The term “environment” includes both the physical habitat that provides the things a population needs to survive (including the geosphere, lithosphere, and atmosphere) and the other living things (biosphere) also found in that location. The abilities of predators in an environment often determine the adaptations of their prey: if a species’ main predator has eyes that primarily detect motion, then the instinct to freeze when spotted is an adaptation to that “environment”.

Beyond survival

The ability to survive in a habitat is not the only factor that determines what features are common in a population. The members of a population also need to be able to reproduce and produce offspring. This can also influence the structures and behaviours of individuals in the population. Examples of this include:

• The necessity to attract a mate in order to reproduce. If there is competition to mate, then males might develop special characteristics to attract a female, even if these make it harder to survive. For example, lyrebirds have evolved long, colourful plumage and extravagant dancing to attract a mate. This also increases the chance of predators finding them.
• The appearance of an individual is a result of the genetic material it inherits from its parents. While this may be modified as a result of the environment (the colour of a thorny devil will become darker in colder weather), plants and animals cannot make complete changes unless their genetic material changes. For example, the thorny devil cannot become purple unless its DNA mutates.
• Random chance can affect how a structural feature evolves. If only a small group of individuals survives an event (i.e., a tsunami), those individuals will carry all of the structural adaptations into future generations (even if they are not most suited to that environment). This is called a genetic bottleneck.

Within a classroom there are often students who raise their hands and offer ideas readily, as well as those who are less confident to share their ideas. The think-pair-share strategy can encourage more students to get involved because it allows thinking time and removes fear of being wrong, as students can offer ideas they have agreed upon with their partner.

In the strategy:

1. Students are prompted with a question, topic, claim or idea.
2. They are given time to think, typically between 10 and 20 seconds. The time can be extended for complex questions or topics.
3. Students pair up with someone near them to discuss their answers and ideas.
4. Invite students to share with the class, starting with “(Student’s name) and I discussed/thought/talked about...”

You can also add the step “square” where pairs team up with another pair to discuss further before sharing. This can be helpful to expose students to a wider range of ideas and vocabulary.

Scientists use models to represent and visualise complex ideas. Models can help bring these ideas into focus, leading to more questions and better explanations. Models are also used to communicate ideas to others. They can be evaluated and refined over time.

In this lesson, students participate in a role-play to explore the role of the mouth/tongue/teeth in feeding, and the different mechanisms and food sources they are suitable for.

In this instance, the role-play gives students a simplified experience of a complex and abstract scientific idea—it is an analogous model exploring how an animal's mouth has evolved to suit the types of food available to it in its habitat and environment.

All scientific models have limitations, and it is critical that students have an opportunity to explore the limitations of the scientific concepts they are modelling. In this case, the simplicity of the model and the materials used cannot really accurately mimic the complexity of an animal's mouth, or how it is used to catch prey that is often moving. However, a scientific model can be deemed effective if it is “good enough” to highlight the specific phenomena it was designed to showcase—that is, the size and shape of the mouth will determine how effective it is at eating different types of food.

The Question Formulation Technique outlines four steps for students to generate, refine, and select useful questions. These steps are:

1. Examine stimulus.
2. Brainstorm questions.
3. Improve questions: change closed questions or statements into open questions.
4. Prioritise questions according to importance, ability to be investigated, what will help with the Act phase, and how it will be answered.

Students should work together in small groups of 3-5.

A nature table is covered in items collected by the students and teachers, such as bark, stems, leaves, flowers, seeds, cones, shells, exoskeletons, scat, pellets, feathers, fur, hair, and photos of local rare and endangered species. 

The nature table is intriguing to many students and something they can all experience success by contributing to. It also provides an opportunity for students to share their knowledge and experiences, reinforcing that we value them and their understandings. A focus on plants and animals that are found locally will make it more relevant for students and will support them to make connections between what they are learning about and their real-life experiences.

Items may need to be returned to students; a collection of small boxes/tubs/trays ensures those items remain separated and labelled while on the table.

Flowers and leaves can be placed in jars of water to prolong their life, or they can be allowed to dry out to observe their changes over time.

As a class, ensure everyone knows which items they are allowed to touch.