During the period of Cenozoic era, co-evolution between plants and animals species occur. It has been profound that certain plants and insects influence another in evolution, in a process known as mutualism where all organisms benefit from each other. They firstly evolve in the aquatic environment before they evolve on land.

Species that co evolve were single cell plant and multicelled eukaryote organism, the blue-green algae was the single cell plant which evolve on the sea. It was the first species to generate its own food in a process known as photosynthesis where sunlight and water are used; during this process oxygen is also generated. While animal cannot produce its own food, they depend direct or indirectly on plants for its survival, and for animal to be evolved on earth it is traced back to plant this show dependency of animal to plant.

The oxygen that the algae produce spread all over the aquatic environment, it began to fill the atmosphere and this made it possible for other organism to develop. Because of high concentration of oxygen produced by algae in the atmosphere, it tends to give access to animal species to evolve on land. Oxygen form part of ozone layer in the upper atmosphere which tends to block the dangerous ultraviolet rays of the sun, these rays was making it impossible for organism to live out of water. But it was simple for plant to survive on land because they can utilise the ultra violet rays into food.

Simplicity of plant to convert sunlight into food made it possible for plant to evolve on land, and the first plant to evolve on land was Mosses. This made it possible for other animal to evolve on land, because of the oxygen generated by plant which forms the ozone layer that block the ultraviolet which restrict life of organisms to exist on land.

Mutualisation which develop between plant species and animal species during co evolution influenced by the resource that one need to survive, plant release oxygen as by products which is used by animal for its survival while animal release carbon dioxide as by products which plant species use it during the process of photosynthesis. For each species to survive it have to depend on the other directly or indirectly.

This dependency between plant and animal species can be seen during reproduction, where plant depends on organism to transfer pollen grains to the female flowers. This helps the plant to reproduce and increase plant population, which is simple method to transfer pollen than wind pollination which need quality seed to be dispersed. While organisms benefit from plant through food and habitant for reproduction that the plant provides, mostly this happens to insects such as moth and bees.

Sometimes plant and organisms become total depend on each other, this happen when one insect only function to pollinate their pollen grains only and it find habitant on the same type of plant ‘s flower. Some become specific to that species only and they protect that species form herbivores. For example, species such as Yucca (Plant) and Moth(organism)they depend on each other yucca provide habitant for moth and allows it to reproduce on its flower where its larvae (caterpillar) live in developing ovary and eat yucca seeds, while moth function as the pollinator.

This mutualism can also be seen in the acacia trees and acacia ants, these ants are specifically depends on the acacia tree for foods. They tend to protect the acacia tree from the herbivores which feed on it and also prune the seeds of any plants that found under acacia tree. This ants sting the animal that feed on acacia or scratch on it, and the ants benefit from the substance that the acacia produce as a food.

In conclusion, plants and organisms depend on each other in a process known as mutualism where all benefit. plant play a role in bring life on earth as the primary producer of factors that sustain life, while animals generate carbon dioxide that sustain plants and also increase the population of plants in the process of reproduction, organisms function as the pollinator.
All in all most of the species in the environment depend directly or indirectly to the other.

References:

1. Kazlev.A.M. 2002, Plants, (Land plants) [Internet] 2003 April 28 [cited 2006 May 08].Available from: http://www.palaeos.com/Plants/default.htm

2. Kohler, S. Plants, [Internet] 2006 May 8, 14:30. UTC [cited 2006 May 07]. Available from: http://www.blueplanetbiomes.org/plants.htm

Largely species of insect organisms have males and females species that mate and reproduce sexually. They can reproduce by lying eggs, while in some insects egg produced inside the female and are born after a short time. And for those species to do reproduction they have to underwent mating period which is different depending on the type of insect’s species. 2

In some insects they have Courtship ritual. Which they perform before they can have mate, while on the other insect there is no sign prior mating, female are often stroked by males, using legs or antennae dance patterns may be performed.2

There is different method that the insect use to attract mating; it can be regarded as mating calls or courtship. Some insects release gland known as pheromones mostly it happens on intraspecific interaction, while intraspecific interaction species release allelochemicals.all this chemical are known as semiochemicals it is used for attraction, repellents and stimulants of male insects species for mating.1

These pheromones are unique for each species to know that there is an insect of the same species which is ready for mating, and it is simple for male species to follow the scent trail. Insect can detect the smell from distance. It was suggested that moth insect can detect the scent close to eleven kilometres. 1

In some species during the arrival at the female territory male secrete the scent for courtship, and it helps females to access the quality and quantity of the male. And most of the scent or pheromones that the male release are the scent from the flowers.

Insect like butterflies use colours and movement for attraction, male butterflies will be attracted by the coloured imitation of females, while other flies also forms a compact swarms that attract the females.1

Other species uses sound for attraction, frogs croak and chucks to attract male frogs for mating and bird sing a song for mating calls. Some insect that use sound for attracting males for mating , are Female grasshoppers, crickets and cicadas males.

Envious, happens in every species, most of the organisms that use signals for mating they have different method to protect their sperms from other male some stay with their mated females to guard them preventing her for mating again. They also extend copulation which prevents other males to mate with her in that period. There is completion for mating in species so they have to prevent other to mate with the species that they mate. some species produce chemicals that plugs the vagina of the female after mating and this give her opportunity for her to mate once while other have genital apparatus that push the arriving sperms back out of the way in the female spermathecae. Because most of the species like to have their own product some have the apparatus that they use to remove the sperms of previous males from females. 1

In general most of the species that cannot undergo courtship they use pheromones and allelochemicals to attract males for mating while other uses sound to indicate that they are ready for mating. So this method of mating call or signals that they use helps the male insect to identify the insect which is ready for mating, different species know signs and smell the scent for attraction of the species of the same group.


Reference

1. Entomology [Internet] updated 2004 [cited 2006- 05- 08] Available from: http://bugs.bio.usyd.edu.au/Entomology/InternalAnatomy/reproduction.html

2. Encyclopedia Smithsonian; Mating Insects, [internet] [cited 2006-05-08] Available from: http://www.si.edu/RESOURCE/FAQ/nmnh/buginfo/mating.htm