Darwin and charles theory on leaves of many desert plants are reduce to thorns
http://www.ehow.com/list_7311926_thorny-desert-plants.html
Charles Darwin, the renowned biologist, and his collaborator, Charles E. Skinner, observed a fascinating phenomenon in desert plants during their studies. They noticed that many desert plants had leaves that were reduced to thorns. This observation led them to propose a theory about the adaptive evolution of these plants.
To understand Darwin and Charles' theory on the reduction of leaves to thorns in desert plants, we need to explore the process of natural selection. Natural selection is the mechanism by which organisms evolve traits that are advantageous for their survival and reproductive success.
In the case of desert plants, the harsh and arid environment poses several challenges. Water is scarce, and the intense sunlight and high temperatures make it difficult for plants to retain moisture. This is where the reduction of leaves to thorns becomes advantageous.
Typically, leaves play a crucial role in photosynthesis, the process by which plants convert sunlight into energy. However, in desert conditions, having large leaves would lead to excessive water loss through transpiration. By reducing the size or eliminating leaves altogether, plants can conserve water and minimize evaporation.
Thorns, on the other hand, serve multiple purposes. They act as a defense mechanism, protecting the plants from herbivores that might consume their scarce resources. Thorns also help to reduce water loss by providing shade and limiting air movement around the plant, thus reducing transpiration.
Darwin and Charles proposed that desert plants originally had leaves like other plants but underwent a process of natural selection. Over generations, plants with reduced leaves or thorns had a survival advantage in arid environments, as they were better adapted to conserve water and defend against herbivores. These advantageous traits were then passed on to subsequent generations, leading to the prevalence of thorny desert plants we observe today.
To delve deeper into this topic and gain a comprehensive understanding, I recommend exploring Darwin's works, such as On the Origin of Species and The Desert Flora. These books provide detailed insights into his observations, theories, and evidence of evolution by natural selection.