Unitary Animals Essay

Townsend et al. (2008)
1. Most animals are unitary organisms; they are both genetically and physiologically separate and therefore these individuals can be easily recognised or set apart. Unitary organisms develop from zygote to adult with determinant form – not modified by environmental conditions. On the other hand, modular organisms form new functional modules (ramets – subunit of the genet that is physiologically viable as an autonomous fragment) from a single genetically unique individual (the genet). Modular organisms grow by repeated interactions (through asexual reproduction) of its parts (modules) into an adult of indeterminate form (coral, poison oak). When the ramets are physiologically independent, they can be counted as individuals,

Modular organisms are sessile and reproduce asexually whilst most animals are unitary and thus are physiologically and genetically set apart from each other due to the fact that reproduce sexually thus bringing about greater genetic variability between and amongst species. In the case of plants they avoid growing below trees or taller plants than themselves because they would experience shading an thus cause them to die or grow much slower due to limitations in gaining light from the sun in order to photosynthesis. In contrast unitary organisms i.e. most animals can distribute themselves according to the resources available to them or in that environment. A unitary animal can release chemicals in order to mark their territory whereas modular organisms mostly cannot. Also due to being sessile they also compete for space and thus cannot grow on land space that has been already occupied by another plant species – thus the tree-grass interactions whereby seeds of most trees cannot start growing on the same space that a grass in growing on due to root depth and competition over resources etc. In both unitary and modular organisms when a favourable mutation occurs on an individual, that individual will be more fit compared to every other individual in the population and has a greater advantage in passing on its genetic material to generations to come compared to other individuals in a population. When looking at a population that is unitary and lives in herds, they live on the idea that there is safety in numbers and also there is a greater chance of finding food (e.g. patch of desirable grass) as a group than