Today we watched an animated version of "The Elephant's Child," one of Rudyard Kipling's Just So Stories from the early 1900s. Here's the link for the 12-minute video:
Elephant's Child animated video
The idea that an individual can change in its lifetime and pass on this change to its ancestors is known as Lamarckism, for its founder, or "Inheritance of Acquired Characteristics." All strange traits can be explained this way, as the adaptation of an elephant's trunk was in the story—stretched out by a predatory crocodile, a trunk was useful, so all elephants after that had long trunks.
Instead, biologists understand that these strange features are brought about by natural selection, a slow process that results in generation-by-generation changes in a trait. Natural selection starts with random genetics mutations that create a new version of the trait that give individuals a survival and/or reproductive advantage. Then, the genes that cause those traits get passed on to more offspring in the next generation.
How could natural selection have worked to fashion an elephant's trunk from ancestors who didn't have a trunk?
2nd assignment: Birds descended from a dinosaur ancestor that had 4 legs and no wings. Describe how birds might have first developed wings:
a) as a "Just So Story."
b) using the step-by-step ideas of natural selection. Thus, rudimentary (basic) wings must have been advantageous, even if they weren't complete like the wings of modern birds.
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