# Why are there pygmy or mini versions of animals?

**URL:** <https://boards.straightdope.com/t/why-are-there-pygmy-or-mini-versions-of-animals/491755>\
**Category:** Factual Questions\
**Created:** [April 2, 2009, 8:10pm UTC](https://boards.straightdope.com/t/why-are-there-pygmy-or-mini-versions-of-animals/491755 "2009-04-02T20:10:48Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![HorseloverFat](https://avatars.discourse-cdn.com/v4/letter/h/8e8cbc/32.png) [@HorseloverFat](https://boards.straightdope.com/u/HorseloverFat)\
**Post date:** [April 2, 2009, 8:10pm UTC](https://boards.straightdope.com/t/why-are-there-pygmy-or-mini-versions-of-animals/491755/1 "2009-04-02T20:10:48Z")

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Is there a biological reason why so many animals have a pygmy or mini version of themselves? Is there a niche they fill that normal sized animals cant? Is there a pygmy gene carrier all animals have an ancestor with?

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**Author:** ![BlinkingDuck](https://avatars.discourse-cdn.com/v4/letter/b/eada6e/32.png) [@BlinkingDuck](https://boards.straightdope.com/u/BlinkingDuck)\
**Post date:** [April 2, 2009, 8:16pm UTC](https://boards.straightdope.com/t/why-are-there-pygmy-or-mini-versions-of-animals/491755/2 "2009-04-02T20:16:57Z")

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WAG

There are probably isolated and have limited resources so evolution favors a smaller, less resource needy animal…

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**Author:** ![Lemur866](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lemur866/32/434_2.png) [@Lemur866](https://boards.straightdope.com/u/Lemur866)\
**Post date:** [April 2, 2009, 8:53pm UTC](https://boards.straightdope.com/t/why-are-there-pygmy-or-mini-versions-of-animals/491755/3 "2009-04-02T20:53:43Z")

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Think about humans. There are a many simple mutations that will cause human beings to be very short in adulthood (see [Dwarfism - Wikipedia](http://en.wikipedia.org/wiki/Dwarfism)). If an environment exists where smaller organisms have more offspring, those genes become fixed and after several generations every member of the population will have them.

On islands large species tend to get smaller while small species tend to get larger:

> **[Insular dwarfism](https://en.wikipedia.org/wiki/Insular_dwarfism)**
>
> Insular dwarfism, a form of phyletic dwarfism, is the process and condition of large animals evolving or having a reduced body size\[a\] when their population's range is limited to a small environment, primarily islands. This natural process is distinct from the intentional creation of dwarf breeds, called dwarfing. This process has occurred many times throughout evolutionary history, with examples including dinosaurs, like Europasaurus and Magyarosaurus dacus, and modern animals such as elephan Th...

> **[Island gigantism](https://en.wikipedia.org/wiki/Island_gigantism)**
>
> Island gigantism, or insular gigantism, is a biological phenomenon in which the size of an animal species isolated on an island increases dramatically in comparison to its mainland relatives. Island gigantism is one aspect of the more general "island effect" or "Foster's rule", which posits that when mainland animals colonize islands, small species tend to evolve larger bodies, and large species tend to evolve smaller bodies (insular dwarfism). This is itself one aspect of the more general phenom...