UCSB Science Line
Sponge Spicules Nerve Cells Galaxy Abalone Shell Nickel Succinate X-ray Lens Lupine
UCSB Science Line
Home
How it Works
Ask a Question
Search Topics
Webcasts
Our Scientists
Science Links
Contact Information
Why does the Earth have grass?
Answer 1:

This is an interesting question -- "why" questions are very difficult to answer. While there are several levels of "why" a person could ask, ranging from existential/philosophical to mechanistic, I think we can probably answer the "why didn't grass go extinct" question. It seems that grass evolved about 65 million years ago, proliferating mostly after the Cenozoic period, which is when the mass extinction of dinosaurs is thought to have occurred. Grasses are hard to chew and digest for many animals, which suggests at least from an evolutionary standpoint why they flourished: the many herbivores that were left over after the mass extinction would have a tough time eating them.


Answer 2:

Grass is a plant (actually, it's a family of plants). Plants grow where plants grow. Grass, being an herb (a non-woody plant), tends not to live where it can get shaded by trees, so you generally get grasses mainly in areas where the trees are sparse (there are grasses that do tolerate shade, but most do better in sun).



Click Here to return to the search form.

University of California, Santa Barbara Materials Research Laboratory National Science Foundation
This program is co-sponsored by the National Science Foundation and UCSB School-University Partnerships
Copyright © 2015 The Regents of the University of California,
All Rights Reserved.
UCSB Terms of Use