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Question

Savanna ecosystems are tropical grasslands with warm temperatures year-round and are characterized by grasses, small and tall trees that are dispersed. Describe how an adaptation may have allowed giraffes to survive in savanna ecosystems. Then suppose a population of giraffes in a certain savanna thrives. More giraffes eat more leaves from the trees, until the trees that are closest to the ground are picked clean. Which giraffes would be most likely to survive in this changing environment?

Answer 1

Hi Vika! This is a classic question, contrasting the hypotheses put forward by Charles Darwin and another famous scientist, Jean-Baptiste Lamarck. The short answer is: giraffes with longer necks are going to survive. However, to provide a bit more description, I want to talk about Lamarck and Darwin's ideas on this. Keep in mind the theory of evolution wasn't well known yet. While both believed that traits could be transferred from parents to offspring, they differed in their understanding of how those traits came about. Lamarck believed that behavior drove change, which in this case would mean that individuals who reached up their necks further would develop further necks. By contrast, Darwin believed that traits were determined by random chance before birth, although the probablility of developing certain traits were influenced by the traits of the parents. As we now know, with the advent of DNA, Darwin ended up being more correct.

Here is a blog post also explaining this: https://blog.helix.com/lamarck-darwin-epigenetics-dna/#:~:text=In%20terms%20of%20the%20giraffe,that%20other%20animals%20couldn't.