LORI DUNN SCRATCHBOARD ART
promoting conservation through artistic efforts
10 x 22
We all know the basic premise; giraffes evolved to have longer necks in order to fill an unoccupied feeding niche of African herbivores, as they were able to reach higher browse on the trees.
This was the theory put forth by Jean Baptiste Lamarck in 1809, who suggested that this "reaching up" caused giraffe necks to elongate over successive generations. Later, Charles Darwin gave a more plausible explanation, using his theory on natural selection, suggesting that giraffes with longer necks were able to eat more available foliage, therefore survived longer over those with shorter necks, thereby passing on their genes. But is this all there is to the story?
There was also a theory that giraffes evolved longer necks to attract mates by winning battles with rival males. Giraffe males combat each other in a ritual known as "necking". By swinging and hitting the other male with its neck, or by wrapping it's neck around the other male's in a show of power and strength, a giraffe is able to send the other guy packing, thus winning favor with a female. Clearly, in this theory, males with longer necks would have an advantage and their genes would be forwarded to new generations.
This year, a new theory was put forth, that giraffes have long necks to aid in thermoregulation by increasing the surface area of their bodies through which internal heat can escape. It was further suggested that the somewhat flattened body shape of the animal is an advantage. Giraffes are often observed facing the sun, exposing the least amount of surface area as possible to the heat.
Personally, I'd still like to think that the original hypothesis is correct, and that the other two explanations were simply "bonuses" that helped giraffes out along the way. But this is all about science, and about exploring new ideas and theories as we learn new information about the amazing animals that share our world.