The Glory of Leaves

Summary:

Rob Dunn talks about how and why leaves come in so many different shapes and sizes, using natural selection and competitive exclusion as examples. He starts out by mentioning that most leaves take in light energy and carbon dioxide, and then the plant makes glucose and oxygen through a process called photosynthesis in the chloroplasts. According to the article, leaves can come in so many shapes and sizes because of how they adapted to their location on Earth. "Desert leaves tend to be small, thick-skinned, waxy, or spiny, just like leaves in salty regions or other harsh lands...Rain forest plants have narrow leaves with long, thin 'drip tips', to drain away excess water" (68). These are two examples of how the plants adapted to their environment by changing the size and shape of their leaves based on the amount of water they have access to. Not all plants make their own food. Some plants such as those that live in bogs low on nutrients, are carnivorous plants. They eat animals such as flies. Competitive exclusion affects the shaped and size of leaves. An example of this is in the rain forest, leaves must be big and broad in order to catch the small amount of sunlight that seeps through the canopy. Leaves also change their shape and size as defense, to keep animals from eating their leaves. If you pick up two leaves you will notice how different they look, but on the inside, most leaves have something in common, and that is to take in energy from the sun and convert it into glucose.

Relevance:

This article is relevant to our biology class; because leaves are part of the study of ecology which is the unit we studied term one. We also talked about biomes and the different kinds of plants that lived in each environment based on temperature, precipitation, etc. We also did an entire plant project in term one, study different plants and how they look different from one another. Based on what the leaves looked like, we could tell what kind of plant it belonged to and sometimes we could even tell where it lived.

http://ngm.nationalgeographic.com/2012/10/leaves/dunn-text

Written by Rob Dunn, published october, 2012