A change to the body of a living thing or to the processes going on inside it that enables it to survive better in its surroundings. For example, the shapes of the beaks of Darwin's finches are adaptations to different foods on the Galapagos Islands.
A plant or animal that has been introduced into one location from a different one and is able to survive, often at the expense of existing (native) species. For example, foxes in Tasmania.
Animals or plants that live mainly on or in water.
The incorporation of new material into the body of an animal or a plant following digestion of food or photosynthesis.
The layer of gas that surrounds a planet, especially the Earth. It contains many gases, including oxygen, carbon dioxide and nitrogen.
balance of nature
The numbers of plants and animals tend to change within certain limits. A variety of things influence the population of a species, including predators, food availability, competition with other species, disease and even the weather.
The variety of life. It includes the different plants, animals and micro-organisms, and the habitats in which they live.
The weight of organic material in a living thing. In a food pyramid for an ecosystem, this is the total mass of living material in all the plants or animals at each feeding level.
An animal that mainly eats meat, such as a wolf or a lynx.
The basic building block of a micro-organism, plant or animal.
Any system used to group living things according to shared features. The most commonly used classification system uses Latin scientific names to show evolutionary relationships between groups of living things.
A characteristic group of plants and animals living in a specific region under similar environmental conditions, e.g. the plants and animals of the taiga.
A relationship in which individuals of the same species or of different species living in the same habitat compete for resources. An example is the Galapagos tortoise competing with goats for vegetation.
A tree that has cones containing the seeds from which the next generation of trees will grow. Examples include pines, spruces and firs.
The protection, preservation and management of wildlife and habitats such as rivers, meadows, mountains and forests.
Consumers are living things that cannot make food for themselves. They survive by taking in food that has been made by other living things. A food chain contains several kinds of consumers at different feeding levels: primary, secondary and tertiary (which are usually the top consumers, not eaten by anything else).
A sudden decline in the population of a plant or animal in a particular habitat. For example, a spill from an oil tanker could cause a population crash of shellfish on a rocky seashore.
Organisms that cause decay. They break down the organic substances in dead remains and recycle their raw materials back into the environment. Bacteria and fungi are the most important decomposers.
The chemical breakdown of food into smaller particles. Substances called enzymes carry out the process either inside the body, as in most animals and some plants, or outside, as in micro-organisms. Digestion is usually followed by assimilation.
An organic substance with a complicated structure found in living cells. The structure of the DNA decides whether the cell becomes a mouse, an apple tree or a mushroom!
The scientific study of the processes that affect the distribution and number of organisms, the interactions among them, and the interactions between organisms and their surroundings.
An ecosystem consists of organisms (plants, animals and micro-organisms) interacting among themselves and with their environment (soil, climate, water and light). Examples include a pond, forest, ocean.
The ability of a machine or a living thing to make something happen. Energy exists in several forms. For example, a battery is a store of electrical energy that can light a lamp; food contains chemical energy that can keep us warm and help us to move.
energy transfer
The process by which energy is moved from one point in an ecosystem or food chain to another. The energy is transferred first to plants from the Sun by photosynthesis and then to animals and micro-organisms as chemical food energy when they eat or decompose them. Energy is also transferred to the environment as heat during respiration and movement.
The conditions in which an organism lives. The environment of any living thing is described by its physical, chemical and biological surroundings.
A special chemical found in cells that can help a chemical reaction to happen inside or outside the cell.
The process that results in changes in a population of living things that can be inherited by the following generations. When a population of organisms changes, it is said to evolve.
The process that produces waste chemicals inside an organism. These waste substances have to be removed, for example when we breathe out carbon dioxide made during respiration.
This means a species that no longer exists. The dinosaurs are examples of extinct animals.
Also called fertility. It is a measure of how many offspring an organism (or a female in a species where there are separate sexes) could produce. In humans, it is measured as the number of births per 1000 women of child-bearing age per year.
food chain
A pathway that links different species in a community. In a food chain, energy and nutrients are passed from one organism to another along the direction of an arrow.
food energy
The chemical energy holding together the particles of a food substance, e.g. sugar. Some of the food energy is transferred along the food chain when the organism is eaten or dies.
food web
A community of living things may contain hundreds of different species involved in thousands of different food chains. Different food chains often interconnect to form a large network, called a food web.
Galapagos Islands
A group of islands in the Pacific Ocean, off the west coast of South America, owned by Ecuador. They are home to a wide variety of animals and plants studied by Charles Darwin, the naturalist.
greenhouse effect
The trapping of heat in the Earth's atmosphere by certain gases, such as carbon dioxide, methane and nitrous oxide. Some scientists predict that the temperature and sea level rise associated with global warming could damage the world's biodiversity.
A group of species that share certain features. For example, Panthera is the genus name for all the big cats, but Panthera leo is the lion species and Panthera tigris is the tiger.
The increase in size of an organism by the addition of new cells.
The area in which a living thing lives and finds the nutrients, water, sunlight, shelter and other essentials it needs to survive. Habitats include woodland, seashore and mountain.
An animal that mainly eats plants, such as a snowshoe hare or squirrel.
Also called genetics. This is the study of how the features and characteristics of living things are passed on from one generation to the next.
The effect that one organism has on another or the effect that the environment has on an organism.
A relationship in which individuals of one species or of different species living in a habitat depend on each other for different requirements. For example, herbivores depend on plants for food, but the plants may depend on the herbivores to carry the plants' seeds to a new habitat.
The movement of animals in response to seasonal changes or changes in the food supply. Examples of creatures that migrate include salmon, monarch butterflies and buffalo.
A change in the genetic material (the DNA) of a living thing. Some mutations may change the appearance of the next generation of the organism when it reproduces; others may have no effect at all. When mutations happen inside an organism, it can evolve.
Animals or plants that naturally occur in only one area or region. For example, kangaroos are found only in Australia.
A scientist who studies living things and how they behave.
natural selection
The process by which genetic characters are passed on to successive generations. Over time, natural selection helps species become better adapted to their environment. Natural selection is also known as 'survival of the fittest'; it is the driving force behind the process of evolution.
An essential food substance.
The next generation of a living thing. In humans, offspring are also called children.
An animal that eats a mixed diet of both vegetation and meat. Most humans are omnivores, as are bears.
A chemical substance found inside living things. Organic chemicals contain the element carbon, amongst others.
A living thing, either a plant, an animal or a micro-organism.
The chemical process by which plants use light energy from the Sun to make sugar from water and carbon dioxide gas.
The plant plankton and primary producers in aquatic - ecosystems, such as lakes and oceans.
A group of organisms of the same species, living in a particular area.
A predator is a carnivore. This means that it lives by eating other animals, which are known as its prey. The term predator usually refers to animals that hunt and kill. For example, the lynx is a predator of the snowshoe hare.
Producers form the first feeding level of a food chain because they make the food that supports the other species in the chain. Green plants are the most important producers. They harness the Sun's energy to make food by photosynthesis.
A diagram that uses a stack of rectangles to show how much food is contained by the living things at each feeding level in an ecosystem. Because a lot of food energy is lost as you move along the food chain from the producers (plants) to top consumers (carnivores), the diagram has a pyramid shape. There are pyramids of numbers, biomass and energy.
The process of using materials in the environment more than once. In food webs, it is often the decomposers that break down the bodies of dead animals and plants, so that the chemicals from which they are made are recycled back into the soil and made available again to the plants. The water cycle is another example of recycling a valuable resource.
The process by which organisms release energy from food inside their cells, usually in a chemical reaction with oxygen. The waste products of respiration are water and carbon dioxide gas.
A group of organisms with a unique set of characteristics (like beak shape and behaviour) that distinguishes them from other organisms. If they reproduce, individuals within the same species can produce offspring that can make more offspring.
A type of coniferous evergreen forest found on the southern edge of the arctic areas of North America, Europe and Asia.
A large island off the south coast of Australia.
An idea that is not yet conclusively proved but that, if true, explains certain facts or observations.