The Importance of classification 🤩🤩
- In I/GCSE Biology, accurate classification using the binomial system allows biologists to:
- easily identify existing species and new species
- see how organisms are related
- Identify areas of greater and lesser biodiversity.
- Biodiversity is a measure of the total number of different species in an area. To count the species you need to be able to identify them, which can be tricky if the species are very similar to one another.
- The more accurate the classification system, the easier identification becomes.
- Biodiversity is important because we obtain many products from living things. The more species there are the more choice we will have, both now and in the future.
- Biodiverse areas also much better at recovering from natural disaster (e.g. floods) than less diverse areas.
- Many scientists believe the places of high biodiversity are the places where more time and money should be spent to conserve them as there would be a greater number of species being conserved.
Difficulties with classification 🤯🤯
- Mallard ducks can hybridise with other closely related species to produce fertile hybrid offspring. These offspring then breed with other hybrids or mallard ducks or closely related ducks. As a result, this produces ducks with a continuous range of characteristics, rather than separate species.
- Neighbouring populations of the same species may have slightly different characteristics but still interbreed.
- Sometimes there is a chain of different populations that can all breed with their neighbouring populations but the two populations at either end of the chain cannot interbreed. The chain often forms a ring shape and so these organisms are called a ring species.
- It is hard to divide a ring species into separate species, however, the gulls named below are traditionally considered to be two species – Larus fuscus (the lesser black-backed gull) and Larus argentatus (The European herring gull).
- Classifying the gulls between these two is difficult because there is a gradual change of characteristics between the two species.
- The platypus was difficult to classify as it had a mixture of features characteristic of different types of animal. Eventually it was classified as a mammal as even though it laid eggs, most of characteristics were like that of a mammals e.g. homeotherm, suckles its young etc.
Naming a species
- In I/GCSE Biology, an organism’s scientific name has two Latin words, genus and species. This is called the binomial system. Organisms that share the first word in their name are closely related. Scientists can tell from the name whether two organisms are closely related.
- The binomial system is useful in cases where organisms with common names are different species. A robin in America is not the same bird as a robin the UK. The system is agreed by scientists all over the world to allow them to communicate clearly without misunderstandings.
Keys 🌟🌟🌟
- In I/GCSE Biology, to identify different species you can use a key. This is a key for rats:
Statement: | Next Step: |
1.The animal has a thick bushy tail. Squirrel
The animal has a tail that is covered in layers of skin which look like
scales. Go to 2
2. It has a band of hair that is longer than the rest of the fur Crested rat
Its fur is all the same length. Go to 3
3. It has a short tail. Groove-toothed rat
It has a long tail. Go to 4
4. Its tail is shorter than its body. Brown rat (Rattus norvegicus)
Its tail is longer than its body. Black rat (rattus rattus)
That's the end of the topic!
Drafted by Joey (Biology)