mathematics

Functional extinction

Functional extinction is a mathematics topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Functional extinction rather than just read about it. In short: Functional extinction is the extinction of a species or other taxon such that: It disappears from the fossil record, or historic reports of its existence cease; The reduced population no longer plays a significant role in ecosystem function; The population is no longer viable. There are no individuals able to reproduce, or the small population of breeding individuals will not be able to sustain itself due to inbreed…

Key takeaways

Functional extinction belongs to mathematics; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Functional extinction to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Functional extinction from memory before moving on to harder problems.

Reference excerpt

Functional extinction is the extinction of a species or other taxon such that:

It disappears from the fossil record, or historic reports of its existence cease; The reduced population no longer plays a significant role in ecosystem function; The population is no longer viable. There are no individuals able to reproduce, or the small population of breeding individuals will not be able to sustain itself due to inbreeding depression and genetic drift, which leads to a loss of fitness. In plant populations, self-incompatibility mechanisms may cause related plant specimens to be incompatible, potentially leading to functional extinction if an entire population becomes self-incompatible. This does not occur in larger populations. In polygynous populations, where only a few males leave offspring, there is a much smaller reproducing population than if all viable males were considered. Furthermore, successful males act as a genetic bottleneck, leading to more rapid genetic drift or inbreeding problems in small populations.

Functionally extinct species in modern times Baiji Northern white rhinoceros Ivory-billed woodpecker Imperial woodpecker Yangtze giant softshell turtle South China tiger Bornean rhinoceros Vaquita Fernandina Island tortoise Hyophorbe amaricaulis North Atlantic right whale On May 10, 2019, the Australian Koala Foundation issued a press release that opened with the sentence "The Australian Koala Foundation (AKF) believes Koalas may be functionally extinct in the entire landscape of Australia." The press release was reported by multiple news agencies worldwide, most of which repeated the AKF's statement. Despite this, koalas are not currently considered functionally extinct; while their population has decreased, the IUCN Red List lists them only as "Vulnerable". The AKF's press release was released on the eve of the 2019 elections in Australia, where topics such as climate change were major issues. Distinct animal populations can also become functionally extinct. In 2011, a 3-year survey of the wildlife population in the Bénoué Ecosystem of North Cameroon (the Bénoué, Bouba-Ndjidda, and Faro national parks, and 28 hunting zones surrounding the parks) concluded that the North Cameroon population of cheetahs (Acinonyx jubatus) and African wild dogs (Lycaon pictus) was now functionally extinct. Non-Northern Cameroonian cheetahs are listed as "Vulnerable" by the IUCN Red List.

See also Conservation genetics Mutational meltdown Small population size Extinction vortex Extinction debt

References

Illustrations

Worked examples

Example 1 — a first encounter with Functional extinction

Start with the simplest possible case. Write down what Functional extinction claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In mathematics, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Functional extinction before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Functional extinction ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Functional extinction

In research: Functional extinction appears in mathematics research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Functional extinction in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Functional extinction is common in secondary-school and first-year university syllabi. It links to neighbouring topics Extinction, so understanding it makes those chapters shorter.
In everyday life: Look for Functional extinction outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Functional extinction in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Functional extinction means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Functional extinction out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Functional extinction in simple terms?

Functional extinction is the extinction of a species or other taxon such that: It disappears from the fossil record, or historic reports of its existence cease; The reduced population no longer plays a significant role in ecosystem function; The population is no longer viable. There are no individu…

Why does Functional extinction matter?

Because it connects several mathematics ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Functional extinction?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Functional extinction.