Thursday, 13 June 2013

Venus Flytrap

(Dionaea muscipula)


Domain:          Eukaryotic
Kingdom:        Plantae  
Phylum:          Anthophyta 
Class:               Magnoliopsida             
Order:             Caryophyllales             
Family:           Droseraceae  
Genus:             Dionaea          
Species:           Dionaea muscipula


Root-Maggot Flies

Root-Maggot Fly - Anthomyia oculifera - female
Domain:          Eukaryotic
Kingdom:        Animalia  
Phylum:          Arthropoda 
Class:               Insecta           
Order:             Diptera           
Family:           Anthomyiidae
Genus:             Anthomyia     

Species:           Anthomyia oculifera

Biogeography, Ecology & Habitat

It is native to the bogs and swamplands of North and South Carolina. It has been introduced to a few other states and is also popular as a potted plant in many parts of the world. It prefers lots of sunlight, humid conditions, and nutrient poor, acidic soil. Native Venus flytrap plants have a habitat that has full sun, good air circulation, and porous, well draining, acidic and moist soil that is usually poor in nutrients such as, nitrogen. 



General Adaptations

For reproductive purposes, the flowers of Venus flytraps usually grow on tall stalks far above the leaves. This is so that the insects pollinating the flowers don’t get trapped in the leaves. This is an anatomical adaptation that affects the flowers and the stems. 

Another anatomical adaptation is the hair-like teeth at the edge of the leaves that helps seal the prey inside. Sealing the prey inside prevents other predators from coming along and stealing an insect or any nutrient being washed away by water or rain before the plant can digest them. The leaves are affected because of this adaptation.

Special Adaptation

Since Venus flytraps live in nutrient poor soil, they have adapted to capture and digest insects to supplement their nutrient need.

One of the adaptations that make Venus flytrap a Venus fly trap is its trapping mechanism. The two leaf parts of a trap are laced together by a small stalk called petiole and there is a series of tiny, sensitive hairs. If an unwary insect walks across these hairs, touching two or more of them in succession, the leaf will close quickly, trapping the insect. It is then slowly digested and absorbed by the leaf. Glands on the leaf surface secrete several digestive enzymes that help to digest the insect. The leaf then re-opens for another victim after one is digested.
venus flytrap, carnivorous plant, Dionaea muscipula captures a Daddy Longleggs
This is an anatomical adaptation that affects the leaves of the plant. This is because, the leaves carry out photosynthesis like any other plant, but they also have many sensitive trigger hairs that allow the leaves to close and hair-like teeth at the edge of the leaves to prevent the prey from escaping. It is also a behavioural trait because, the just functions this way. It is also a physiological and chemical adaptation because the tiny, sensitive hairs inside leaves cause the leaves to close, if triggered. There is nectar and a smell that attracts the insects, and there are also glands on the leaf surface that secrete digestive enzymes to help decompose and digest the insect. This adaptation provides the plant with the essential nutrients that it cannot get from the nutrient-poor soil.

Evolution by Natural Selection

If Charles Darwin had found this plant during his travels, he would have explained this adaptation through the idea of the survival of the fittest or natural selection. He would have said that the trait for trapping and digesting insects for nutrients existed in some individuals of the population while it did not exist or was very poor for other individuals. He might have said that Venus flytraps that have triggers which are more sensitive, faster reflexes to close the leaves faster, have teeth at the edge of the leaves and/or produce better digestive enzymes are better suited to survive the local conditions; while the individuals that do not carry these traits will not get enough nutrition to survive, so their population will slowly decline and eventually disappear since they also cannot reproduce. Individuals that are better suited to survive do not need to depend on the soil for nutrition and instead can trap and digest insects for nutrients. They can survive to produce offsprings and pass on these strong, helpful traits. This process has happened and will continue to happen slowly over time.

Lamarckian Evolution

If Jean Baptiste de Lamarck had seen this plant he would have described the evolution of this trait according to the theory of inheritance of acquired traits. He would have said, whatever traits the Venus fly trap has acquired during its lifetime, it has passed it on to its offspring. For example, if the plant grew really healthy because it has received a lot of sunlight, perfect soil condition, and sufficient nutrients, it will pass on this trait to its offspring too and they will also be healthy.