Life in our world is based on a branched network of connections and interactions between different organisms. Basic needs such as food, reproduction, defense, and dispersal are essential to the existence of life and are facilitated by the diverse connections between organisms. These are sometimes predator-prey relationships, sometimes exploitative or parasitic relationships, and sometimes mutualistic relationships, in which both sides benefit.
The Acacia Tree: A Web of Life in the desert
In the arid desert, the acacia tree is a center of life. Dozens of species of animals and plants, living on or near the tree, maintain a complex network of connections with each other, which provides them with food and shelter. For them as for us, the tree is an oasis.
The Food web
All organisms require energy to live. Plants (and some bacteria) acquire their energy from sunlight. All other organisms acquire their energy from the food they eat. Some of them are herbivores – plant eaters. Others are predators or scavengers.
The Acacia Tree: Web of Life in the DesertThe Steinhardt Museum of Natural History
Dorcas gazelle and Gray wolf
Mountain gazelleThe Steinhardt Museum of Natural History
Dorcas gazelle
This herbivorous mammal feeds on the leaves and fruit of the acacia and facilitates seed dispersal across the landscape.
Egyptian spiny-tailed lizardThe Steinhardt Museum of Natural History
Egyptian spiny-tailed lizard
This herbivorous reptile's diet includes the leaves and fruit of the acacia that fall to the ground.
Gray wolfThe Steinhardt Museum of Natural History
Gray wolf
An apex predator it enjoys the tree's shade in the heat of the desert feeds on animals in the tree's surroundings.
Carcal and White-crowned wheateaterThe Steinhardt Museum of Natural History
Caracal and White-crowned wheatear
Organisms like us, who feed on several food sources, are called omnivores. Last are the decomposers, which feed on dead plants and animals, and facilitate the recycling of nutrients in nature.
Nature’s Sanitation Department
Carcasses are fertile ground for a range of disease vectors. Scavengers feed on dead animals and remove them from the environment. In this way they prevent the spread of disease and other sanitation hazards and keep the ecosystems cleaner and healthier.
Like all organisms, humans also cannot live alone on earth. To ensure the existence of the human species we need interactions with all of the natural systems as healthy, diverse, and functioning systems.