Evolution and Inheritance
KS2SC-KS2-D014
Biology domain covering fossil evidence for change over time, variation in offspring, adaptation to environments, and the concept of evolution. Year 6 only. Builds on Y3 fossils and Y5 life cycles.
National Curriculum context
Evolution and Inheritance at upper KS2 introduces pupils to Charles Darwin's theory of evolution by natural selection as the scientific explanation for the diversity of life on Earth. Pupils learn that living things have changed over millions of years and that fossils provide evidence of organisms that lived long ago, connecting this to the geological evidence studied in the Rocks domain. The statutory curriculum requires pupils to understand that offspring are not identical to their parents (variation), that some variations are advantageous in a particular environment (natural selection), and that this can lead to evolution over many generations. This domain provides the conceptual framework for understanding inheritance, genetics and biodiversity at KS3.
4
Concepts
3
Clusters
2
Prerequisites
4
With difficulty levels
Lesson Clusters
Understand how fossils provide evidence that living things change over time
introduction CuratedFossils as evidence of change over time is the evidential foundation for evolution; co_teach_hints link C063 to C066, establishing a logical starting point before variation, adaptation and natural selection are introduced.
Explain variation in offspring and how features are inherited
practice CuratedVariation in offspring is the genetic prerequisite for understanding natural selection; it introduces the idea that offspring are similar but not identical to parents, setting up adaptation and evolution.
Describe adaptation and explain how it can lead to evolution
practice CuratedAdaptation and evolution are directly linked in the co_teach_hints (C066 co-teaches with C065); together they form the core Darwin narrative that variation + adaptation over geological time = evolutionary change.
Teaching Suggestions (1)
Study units and activities that deliver concepts in this domain.
Evolution and Adaptation
Science Enquiry Research EnquiryPedagogical rationale
Research enquiry combined with hands-on modelling (the bird beak simulation) helps pupils understand natural selection through concrete experience rather than abstract explanation. The bird beak activity transforms a complex concept into a physical investigation where pupils can see variation, competition, and differential survival in action.
Prerequisites
Concepts from other domains that pupils should know before this domain.
Concepts (4)
Fossils as Evidence of Change Over Time
knowledge AI DirectSC-KS2-C063
Understanding that fossils (introduced in Y3 as trapped remains in rock) provide evidence that living things have changed over time and that animals and plants that no longer exist once lived on Earth millions of years ago.
Teaching guidance
Revisit fossil knowledge from Year 3 and extend it to the concept of change over time. Compare fossils of extinct organisms with their closest living relatives — for example, ammonites with modern nautilus, trilobites with modern woodlice. Use a geological timeline to show when major groups appeared and disappeared. Discuss what fossils tell us: the types of organisms that existed, the environments they lived in, and how life has changed over millions of years. Link to Darwin's use of fossil evidence in developing his theory of evolution. Examine the concept of extinction — why species disappear and what causes it.
Common misconceptions
Children often think dinosaurs and humans lived at the same time. Dinosaurs became extinct approximately 66 million years ago; modern humans appeared around 300,000 years ago. Some pupils believe that fossils are only of dinosaurs, not recognising the vast range of fossilised organisms (plants, shells, fish, insects). Children may think that if a species goes extinct, it was somehow 'inferior', rather than understanding that extinction results from environmental change exceeding a species' ability to adapt.
Difficulty levels
Knowing that fossils show us animals and plants that lived long ago, and that some of them no longer exist (are extinct).
Example task
Look at this ammonite fossil. What does it tell us?
Model response: This fossil shows an animal that lived a very long time ago. It looks like a spiral shell. This animal does not exist any more — it has gone extinct. The fossil tells us that different animals lived on Earth in the past.
Understanding that fossils provide evidence that living things have changed over time — organisms that lived millions of years ago were different from those alive today.
Example task
Scientists have found fossils of sea creatures on top of mountains. What does this tell us?
Model response: This tells us that the land where the mountains are now was once under the sea. Over millions of years, the sea floor was pushed up to form mountains, carrying the fossils with it. This is evidence that the Earth's surface has changed dramatically over time, and that the environments where organisms lived have changed too. Life on Earth has changed alongside these changes — the sea creatures that made those fossils are long extinct.
Using fossil evidence to explain that organisms have changed over time, comparing fossils with living organisms, and understanding what fossils reveal about past environments.
Example task
Compare a fossil of an ancient horse (Eohippus, the size of a dog with four toes) with a modern horse. What does this comparison suggest?
Model response: Eohippus (about 55 million years ago) was small (about 40cm tall, dog-sized), had four toes on each front foot, and had teeth suited to eating soft leaves in forests. Modern horses are much larger (about 160cm), have a single hoof on each foot, and have teeth suited to grinding tough grass on open plains. The fossil record shows a gradual series of changes between the two: increasing body size, reduction in toe number, and changes in tooth structure. This evidence suggests that horses have evolved over millions of years, changing as their environment changed from forests to grasslands. The intermediate fossils show this was not a sudden jump but a gradual process — each generation was slightly different from the last.
Evaluating fossil evidence critically — understanding gaps in the fossil record and why not all organisms fossilise — and explaining how fossils support the theory of evolution.
Example task
Why do we not have fossils of every species that has ever lived? Does this weaken the evidence for evolution?
Model response: We do not have fossils of every species because fossilisation requires very specific conditions: the organism must be buried quickly in sediment before it decays, and the sediment must remain undisturbed for millions of years while minerals replace the original material. Soft-bodied organisms (like jellyfish and worms) rarely fossilise because they have no hard parts. Many fossils have been destroyed by geological processes — erosion, volcanic activity, tectonic movement. So the fossil record is necessarily incomplete — like having some pages of a very long book. This does not weaken the evidence for evolution. The fossils we do have consistently show: simpler organisms in older rocks, more complex ones in newer rocks; gradual changes within lineages over time; transitional forms (like Archaeopteryx, between dinosaurs and birds). No fossil has ever been found in the wrong geological layer. The pattern is overwhelmingly consistent, even with gaps.
Delivery rationale
Science knowledge concept — factual content deliverable with visual representations and adaptive quizzing.
Variation in Offspring
knowledge AI DirectSC-KS2-C064
Understanding that living things reproduce offspring of the same kind, but that offspring vary and are not identical to their parents or to each other. This natural variation within species is the raw material for natural selection. Genes/chromosomes not required at this stage.
Teaching guidance
Explore variation within the class — measure hand span, height, arm length, eye colour, and discuss why no two people are identical (except identical twins, who share DNA). Compare parents and offspring using photographs: children resemble their parents but are not identical to them. Investigate variation in other organisms — leaf size in a species of tree, shell patterns in snails. Distinguish between inherited variation (eye colour, nose shape) and environmental variation (scars, hairstyle, language). At this stage, genes and chromosomes are not required, but the idea that characteristics are passed from parent to offspring through reproduction should be established.
Common misconceptions
Children often think offspring are exact copies of their parents or an exact 50/50 mix. Offspring inherit a combination of characteristics but the expression is complex and not a simple blend. Some pupils confuse inherited characteristics with learned or environmental characteristics — speaking English is environmental, not inherited. Children may believe that individual organisms can change their characteristics during their lifetime and pass these changes to offspring (Lamarckian inheritance), which is incorrect.
Difficulty levels
Knowing that children look similar to their parents but are not identical copies — there are always some differences.
Example task
Look at this family photo. In what ways does the child look like the parents? In what ways are they different?
Model response: The child has brown eyes like their dad and curly hair like their mum. But the child's face shape is different from both parents, and they are shorter than both parents were at the same age. Children look a bit like each parent but are not exactly the same as either one.
Understanding that offspring inherit characteristics from both parents, which explains both similarities and differences between family members.
Example task
Why do brothers and sisters look similar but not identical (unless they are identical twins)?
Model response: Brothers and sisters each receive a mix of characteristics from the same two parents. But the particular mix is different each time — like shuffling a deck of cards and dealing different hands. One child might get their mum's eye colour and dad's hair type, while their sibling gets the opposite combination. This is why siblings share some features but look different overall. Identical twins look the same because they developed from one fertilised egg that split, so they have exactly the same mix.
Distinguishing between inherited variation (passed from parents) and environmental variation (caused by conditions), and understanding that variation within a species is normal and important.
Example task
Which of these are inherited and which are caused by the environment: eye colour, spoken language, natural hair colour, a scar, height, ability to play piano?
Model response: Inherited: eye colour (determined by characteristics from parents), natural hair colour (same). Environmental: spoken language (learned from the community you grow up in), ability to play piano (learned through practice), a scar (caused by an injury). Height is both — you inherit a potential height range from your parents, but your actual height depends on nutrition, health and other environmental factors during growth. Many characteristics are influenced by both inheritance and environment. This variation within a species is normal and important — in nature, variation means that if conditions change, some individuals may be better suited to survive than others.
Explaining why variation is essential for a species' survival and connecting variation to natural selection without using genetic terminology.
Example task
A deadly disease hits a population of rabbits. Most die, but a few survive. Explain why variation in the population was crucial for the species' survival.
Model response: Within the rabbit population, natural variation means that not all rabbits are identical. Some may have a slightly different immune system that happens to be better at fighting this particular disease. These rabbits survive while others do not. The survivors reproduce, passing on their disease-resistant characteristics to their offspring. Over several generations, more rabbits in the population carry this resistance. Without variation, every rabbit would be equally vulnerable and the entire population could be wiped out. This is why variation is crucial for species survival — it is like having many different keys; if the lock changes (new disease, new predator, new climate), at least one key might still fit. Species with very little variation (like cheetahs) are at greater risk of extinction because they have fewer 'keys' to try. This is the foundation of natural selection — variation provides the raw material for species to adapt to changing conditions.
Delivery rationale
Science knowledge concept — factual content deliverable with visual representations and adaptive quizzing.
Adaptation
knowledge AI DirectSC-KS2-C065
Understanding that animals and plants have features that help them survive in their particular environment. These adaptations may be structural (camouflage, body shape, insulation) or behavioural. Different environments select for different adaptations.
Teaching guidance
Use striking examples of adaptation to engage pupils: polar bear fur (insulation and camouflage), cactus spines (reduced water loss), giraffe neck (reaching high vegetation), woodpecker beak (drilling into wood). Compare organisms from different environments — arctic versus desert, deep sea versus rainforest — and identify how their features help them survive. Challenge pupils to design an imaginary animal adapted to a specific environment, justifying each feature. Investigate examples of camouflage using peppered moth photographs. Distinguish between structural adaptations (physical features) and behavioural adaptations (migration, hibernation, nocturnal activity).
Common misconceptions
Children commonly think that individual animals deliberately adapt or choose to develop helpful features in response to their environment (e.g., 'giraffes stretched their necks to reach high leaves'). Adaptation occurs over many generations through natural selection, not within an individual's lifetime. Some pupils think adaptation means animals are perfectly suited to their environment — in reality, organisms are 'good enough' rather than optimal. Children may believe that adaptation is a conscious or intentional process.
Difficulty levels
Knowing that animals and plants have features that help them survive in the place where they live.
Example task
A polar bear has thick white fur. How does this help it survive in the Arctic?
Model response: The thick fur keeps the polar bear warm in the freezing cold. The white colour helps it hide in the snow so it can sneak up on prey without being seen.
Identifying multiple adaptations in an organism and explaining how each helps survival in its specific environment.
Example task
A cactus lives in a hot, dry desert. Describe three adaptations and explain how each one helps.
Model response: 1. Spines instead of leaves — small surface area means less water is lost through evaporation. Spines also protect the cactus from animals that might eat it for water. 2. Thick, fleshy stem — stores water from rare rainfall, allowing the cactus to survive long dry periods. 3. Long, spreading roots — extend over a wide area just below the surface to collect water quickly when it rains. Each adaptation solves a problem created by the desert environment: extreme heat, very little rainfall, and animals seeking water.
Comparing adaptations in organisms from different environments and explaining why the same adaptation would not work everywhere.
Example task
Compare a camel (desert) and a penguin (Antarctic). Both survive in extreme environments but have very different adaptations. Why?
Model response: Camel adaptations for the hot, dry desert: humps store fat (not water) for energy when food is scarce; long eyelashes and closeable nostrils protect against sandstorms; wide feet spread weight on soft sand; can tolerate high body temperature to avoid sweating and water loss. Penguin adaptations for the freezing Antarctic: thick layer of blubber insulates against extreme cold; waterproof overlapping feathers trap air for insulation; huddle behaviour reduces heat loss; streamlined body and flipper-like wings for efficient swimming to catch fish. These adaptations are opposites because the environments demand opposite solutions. A camel's adaptations would be useless in Antarctica — it needs to conserve water, not heat. A penguin's thick blubber would cause overheating in a desert. Adaptations are specific to the challenges of each environment.
Explaining that adaptations develop over many generations through natural selection, not within an individual's lifetime, and predicting how a changing environment might affect adapted organisms.
Example task
If the Arctic ice melts due to climate change, what problems might polar bears face? Use your knowledge of adaptation to explain.
Model response: Polar bears are highly adapted to Arctic ice: white fur for camouflage on ice and snow, large paws for walking on ice, thick blubber for swimming in freezing water, and hunting behaviour that depends on sea ice as a platform for catching seals. If the ice melts: their white camouflage becomes a disadvantage on dark water or land. Seal-hunting platforms disappear, reducing food availability. Bears must swim longer distances, using energy and risking drowning. Competition with grizzly bears (already adapted to ice-free environments) increases. Crucially, adaptation happens over many generations — polar bears cannot simply adapt to ice-free conditions within a few decades. Evolution by natural selection requires many generations. If the environment changes faster than a species can adapt, the species faces extinction. Some polar bears might survive if they have variations that help them hunt on land, but the population would decrease dramatically. This is why rapid environmental change is so dangerous — it outpaces the natural pace of adaptation.
Delivery rationale
Science secondary_research concept — data-driven activity well-suited to digital delivery.
Evolution
knowledge AI DirectSC-KS2-C066
Understanding that adaptation may lead to evolution — that over very long periods of time, variation and natural selection can lead to populations becoming better adapted to their environments and to the development of new species. Work of Darwin and Wallace.
Teaching guidance
Build from the concepts of variation, inheritance and adaptation to explain evolution by natural selection: organisms vary; those with advantageous variations are more likely to survive and reproduce; their offspring inherit these variations; over many generations, the population changes. Use the peppered moth example (light moths on soot-covered trees during the Industrial Revolution) as a well-documented case study. Discuss Darwin's and Wallace's contributions and the evidence they gathered. Use simulations (e.g., bird beak tools picking up different 'food' types) to model natural selection. Emphasise the timescale — evolution typically occurs over thousands or millions of years, not within a single lifetime.
Common misconceptions
The most common misconception is that individual organisms evolve during their lifetime — evolution occurs across populations over many generations. Children may think evolution has a goal or direction ('aiming' towards a perfect form), when it is an undirected process driven by environmental pressures. Some pupils confuse evolution with metamorphosis (a frog changing from tadpole) or with individual growth. Children may think that evolution means species 'improve' over time, rather than understanding that species become better adapted to their current environment.
Difficulty levels
Knowing that animals and plants have changed over a very long time and that some types of living things that existed before are now extinct.
Example task
Dinosaurs lived millions of years ago but are not alive today. What do we call it when a type of animal no longer exists?
Model response: When a type of animal no longer exists anywhere on Earth, we say it has become extinct. Dinosaurs are extinct. We know about them from their fossils.
Understanding that living things have gradually changed over very long periods of time (evolution) and that variation and inheritance play a role in this process.
Example task
How might a population of mice gradually change colour over many generations?
Model response: Imagine a population of brown mice living on brown soil. Some mice are slightly darker and some slightly lighter due to natural variation. If the environment changes and the soil becomes lighter, darker mice are more easily seen by predators and more likely to be eaten. Lighter mice survive longer and have more babies. Those babies inherit the lighter colour. Over many generations, the population gradually becomes lighter. This is evolution — gradual change in a population over many generations.
Explaining evolution by natural selection using the concepts of variation, inheritance and survival, with reference to Darwin and Wallace.
Example task
Explain how Darwin's theory of evolution by natural selection works, using the peppered moth as an example.
Model response: Before the Industrial Revolution, most peppered moths were light-coloured, camouflaged against pale lichen-covered tree bark. Dark moths were rare and easily spotted by birds. During industrialisation, soot blackened the trees. Now light moths were visible and eaten, while dark moths were camouflaged and survived. Dark moths reproduced more, passing on their dark colouring. Within a few decades, most peppered moths in polluted areas were dark. After clean air laws reduced pollution, lichens returned, and the population shifted back towards lighter moths. This demonstrates Darwin and Wallace's theory: (1) individuals vary (light and dark moths exist); (2) some variations give a survival advantage in the current environment; (3) survivors reproduce and pass on advantageous traits; (4) over generations, the population changes. Natural selection does not have a goal — it is simply the result of better-adapted individuals surviving and reproducing more successfully.
Evaluating the evidence for evolution from multiple sources and understanding why evolution is considered a scientific theory supported by overwhelming evidence, not 'just a guess'.
Example task
Some people say 'Evolution is just a theory.' In science, what does 'theory' mean? What evidence supports the theory of evolution?
Model response: In everyday language, 'theory' means a guess. In science, a theory is an explanation supported by a large body of evidence that has been tested repeatedly and never disproven. The theory of evolution is supported by: (1) Fossil evidence — showing gradual changes in organisms over time, including transitional forms. (2) Comparative anatomy — similar bone structures in different species (a human arm, a whale flipper, a bat wing all have the same bones) suggest a common ancestor. (3) DNA evidence — species that look similar have similar DNA; the more similar the DNA, the more recently they shared a common ancestor. (4) Observable evolution — bacteria developing antibiotic resistance, the peppered moth, dog breeding producing different breeds from wolves. (5) Biogeography — island species resemble nearby mainland species but with unique adaptations. No scientific evidence contradicts evolution. Like the theory of gravity, it is called a theory because it explains a vast amount of evidence — not because scientists are unsure about it.
Delivery rationale
Science secondary_research concept — data-driven activity well-suited to digital delivery.