Study Guide

Plant Evolution and Diversity

Plant Evolution and Diversity Introduction

Let's imagine a world without plants. Oh that was really really scary. Never mind, don't imagine a world without plants. You know what we saw in that imaginary world? Nothing. Absolutely nothing. That's right. In our imagined, non-plant world, there was No. Life. At. All. (Gasp.) It was dark, and slimy, and surprisingly toxic to breathe.

But that is just an imaginary world anyway, right? In reality, life does not depend that much on plants. After all, vegetables are gross and we don't need grass lawns to play on anymore because we have iPhones and videogames, and football fields are all turf these days. Right?
Well…maybe that is a bit of an exaggeration. Maybe a few plants are okay. Like, palm trees are pretty scenic and strawberries are delicious. Also, chocolate is really tasty and it does technically come from a plant. It's also nice to be able to print something out on paper and put gas in the car, and those products come from plants. Yup, paper comes from trees and gasoline comes from dead plants that lived thousands of years ago. All right, so plants are not so bad after all. In fact, they are actually pretty useful.

Plants are not just useful; they can be interesting too. Interesting in the way that reading the dictionary is "interesting"? No…plants are sexually promiscuous. That's right. They spread their sperm all over the place trying to make babies. Because they spread their sperm, and sometimes their seeds, we have allergies, food, and an atmosphere with oxygen. The allergies are not so good, but the food and atmosphere aren't half bad.

The plants we see outside today have evolved over millions of years. The ancestors of plants lived in the ocean, as teeny, tiny bacteria that could photosynthesize. That is, they could convert sunlight into food. Those bacteria, called cyanobacteria, started living on land about 1.2 billion years ago. They made our atmosphere hospitable to more life. By making an atmosphere that we could breathe in, they paved the way for animal life, including humans.

Of course, plant evolution only started with cyanobacteria. Bacteria aren't plants but they did develop some crucial cellular machinery for photosynthesis. Then came algae, then mosses, and a bunch of other plants, and we couldn't help but noticing, but there are a lot of different plants out there. How many? Almost 300,000 kinds of plants. Whew. Hope you don't have to memorize them all for the test…

Plant Evolution and Diversity Resources

Websites

How Evolution Works
The UC Berkeley Museum of Paleontology has a great website for students trying to understand how evolution works. Please excuse the MS Paint diagrams. Public universities have limited resources.

Plant Evolution Timeline
If you love colorful graphs talking about plant evolution, have we got the website for you. This timeline lets you see the different evolutionary events in the plant world.

Intro to Phylogenetics
Here's an introduction to phylogenetics from the National Center for Biotechnology Information. There are a lot of words on the page, but it's a good primer if you're curious about the flakiest of all the sciences. Wait, that's phyllogenetics. Nevermind.

Radiometric Dating
Combine the words "radioactive clock" and "Cambrian explosion," and you either have the best supervillain scheme ever or an article on radiometric dating. We'll let you decide for yourself.

Evolve or Perish Game
Imagine combining all the wonders of Chutes and Ladders with the glory of evolution. Then add tiles like "Hop ahead one on a giant mammal" or "Chomped on by a T. rex. Lose a turn." Then call it "Evolve or Perish." Download it for free, and have the most epic board game party ever.

Images

Carboniferous Slideshow
National Geographic is the king of awesome science-related slideshows. Check out this one with images of the Carboniferous Period.

Fossil Plant Pictures
The only thing better than pictures of plants are pictures of really old plants, arewerite? Enjoy it in all its plant-y goodness.

Videos

Michael Pollan TED Talk
Author Michael Pollan gives a TED talk about seeing the world from a plant’s point of view. And if we really are all pawn's in corn's evil plan of world domination, we're in big trouble.

David Attenborough Wins at Life
See the transformation as plants flower, fern fronds unfurl, and David Attenborough narrates in a short clip from the BBC's Life. We really wish he would narrate our lives. It would be like living Harry Potter.

Jonathan Drori TED Talk
Get up close and personal with pollen. Unless you're allergic, in which case, you're excused.