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title: "5.2 Phenotype in a model"
canonical: "https://wiki.groenkennisnet.nl/space/TAB/288686169/5.2%20Phenotype%20in%20a%20model"
format: markdown
---
As we have seen, anything that has happened during the life history of the animal may have an influence on the current phenotype. For example, if you measure the height of an animal, then that is its phenotype. Genetics will play a role in the height because if the genes determine that the animals will stay small, it can eat as much as it likes but it will never grow big: *the genetic makeup sets the boundary*. However, if that same animal does not get fed properly, or gets ill, or lives in a very cold climate, or his mother was ill when she was pregnant of the animal, the animal will not even reach that boundary and stay smaller than an animal of the same genetic makeup that had the best circumstances for growth. These environmental influences are not always easy to pinpoint because they start so early (oocyte and sperm experience environmental influences as well), but also because it is not always clear what is of influence and what not.

> ℹ️ ### Definition
> ℹ️ 
> ℹ️ *The ****environment**** can be defined as anything that influences the animal’s performance that is not related to the genetic makeup of the animal, starting at the earliest possible moment in life, even before conception.*

In general you can consider the following basic model:

> ℹ️ ###  Model 
> ℹ️ 
> ℹ️ ### *Phenotype = Genotype +   Environment*
> ℹ️ 
> ℹ️ *Or*
> ℹ️ 
> ℹ️ *P = G + E*
> ℹ️ 
> ℹ️ These symbols P and G and E are important to remember as they are very commonly used to describe phenotype, genotype, or ‘environment’