One big reason for this is because individuals of the same species often have to fight over shared resources (this means shared food and shared environment).
Because they fight over a limited amount of space and food, competition between individuals within one species can be present and very tough.
On the other hand, having members of different species also possibly means different territories and different food sources. A lion has no quarrel with dolphins, while it can have a lot of fights with lions from different prides (large group of lions).
<span>Sterilization of animals reduces the level of circulating reproductive hormones leading to increased longevity, typically due to reduce cancer mortality. The primary aim of animal sterilization is avoiding overpopulation, but this increased longevity could be an added benefit for an individual animal.</span>
Animal body is made of four different types of tissues.
Epithelial Tissue
Muscle Tissue
Connective Tissue
Nerve Tissue
Plant structure is different from the animal skeletal structure. A plant tissue is different from those in animals. Plant tissues are basically divided into two: Meristematic tissue and Permanent tissue.