Cactus and Lizard Symbiosis

cactus Symbiosis is one of the more interesting processes on our planet today. What happens in a symbiotic relationship is that two organisms are in a mutually dependent relationship to such an extent that they totally supply each other's needs. In New Scientist, July 3, 1993, page 15, is an article by Jonathan Beard about two forms of life that have an incredible example of symbiosis-the lizard Tropidurus torquatus and the cactus Melocactus violaceus. House

What happens in this situation is that the cactus provides the lizard with food and water and the lizard provides for the reproduction of the cactus in a unique way. These two life forms exist in the Linhares Game Preserve north of Rio de Janeiro, a very hot place where air temperatures can exceed 50°C (over 140°F) during the hottest time of the day. Every day the cactus produces anywhere from one to four small pink fruits which it pushes up and out of the top of the cactus. Dr. João Vasconcellos-Neto, who has been studying these two life forms says "The exposure of the fruit is synchronized with the lizard's period of greatest activity in the morning. As the temperature goes up, the velocity with which the fruits rise increases, and they are left most accessible to the lizards."

When the lizard sees a fruit, it climbs up the side of the cactus and grabs it. The fruit has a high water content so it is valuable to the lizard. The seeds pass through the lizard's intestinal tract and are dispersed to other areas as the lizard defecates. Each fruit contains 22 seeds on the average. The amazing thing is that the seeds of the cactus will not germinate unless they go through the lizard's digestive system. Scientists are unsure of the cause, but apparently there are chemicals in the lizard's digestive system which trigger germination. Seeds taken from the cactus and put into soil will not sprout-no matter how good the soil is or how much moisture is present. Only the digestive system of the lizard will trigger the germination of the seeds. Scientists have not been able to find any another animal that eats the fruit of the cactus. Apparently the lizard is the sole agent responsible for the reproduction of the cactus.

One can propose hypothetical scenarios which would suggest how these two life forms may have become dependent upon each other, but we would suggest that there is a plan here which makes life possible in a very inhospitable environment. By providing two life forms, a bridge to solve their most pressing survival need, an ecological niche is uniquely provided for.

This bridge is difficult to explain on a chance basis because so many things could disrupt it. As Romans 1 says, "We can know there is a God through the things He has made." This design shows wisdom that speaks of this making.

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