DNA

DNA consists basically of 2 parts, the Sugar-phosphate backbone which forms the double helix, and pairs of Bases that form the linkage between the helices. Genetic codes are passed along by the sequence of pairing between the Bases. Various physical and chemical forces come into play in the the DNA , both repulsive and attractive, that cause its particular form.

Rainforest Ecosystems

A Rainforest ecosystem is a large physical environment which is home a huge variety of wildlife. Although the flora and fauna are all subject to the same larger conditions of the rainforest, several environmental factors vary depending on which layer of the jungle they belong to. There are 4 layers to the forest, each of which is perfectly adapted to the particular set of conditions that exist in its immediate vicinity. The forest itself works as a comprehensive system; several parts that come together to form a whole.

The regions of the forest are:

The Emergent Layer
Tall trees that are over 200 feet in height form this layer.

Conditions:

High wind speeds, plentiful sunlight

Adaptations:
Small leaves with waxy coatings to avoid water loss
Proliferation is through wind dispersal of seeds

The Canopy Layer
This layer consists of trees with a wide spread that form an umbrella over the lower parts of the forest.

Conditions:
Abundant sunlight, lots of rainfall

Adaptations:
These trees have very dense foliage to capture maximum sunlight
Since the leaves are very dense, they hold a lot of water during rainfall, and are adapted with special ‘drip tips’ that allow water to drip out easily

The Under canopy/Shrub Layer
This layer is formed of smaller plants and trees that exist right above the forest floor.

Conditions:
Very little sun due to the shelter of the canopy layer, very little air movement or evaporation occurs here.

Adaptations:
Broad leaves to capture maximum sunlight
Pollination by insects and animals
Many plants form symbiotic or parasitic relationships with larger trees

The Forest Floor

Conditions:
The floor of the forest has almost no sunlight, and very little air movement. Humidity is excessive due to the moisture trapped by upper layers.
No vegetation grows here, but it is rich and fertile ground because the conditions favour quick decomposition of fallen leaves.

Anthill Optimization

A very interesting aspect of ants arrange their environment, is their process of finding and maintaining the shortest route between a source of food and the anthill.
Ants wander randomly while foraging for food and upon finding a source, they return to the anthill so as to transport the food back. They lay pheromones along their path so that others may come across and recognize it. If other ants find such a trail, they abandon their wandering and follow it, thus reinforcing the path with pheromones of their own.
A process of positive feedback occurs to strengthen the shortest path. Pheromones evaporate over time, thus making longer paths weaker – the longer it takes the ant to travel a path, the more time the pheromones have to evaporate. The shorter paths are also reinforced because of the number of times the ant can travel over it in a shorter span of time, thus attracting other ants to a stronger scent of pheromones.