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Evolution of Multicellularity--animals, plants, fungi

Wish List

Multicellularity
- multiple origins
- experimental appearance in lab
- role in origin of plants/animals
Fungi Diversity--major groups
Animal diversity
- Cambrian Explosion and Burgess Shale, appearance of shells
- Major groups of animals
- Major events during paleontological history
  - How are geological eras defined?
  - Role of end Permian, end Cretaceous extinctions
Plant Diversity
- Origin of plants
- Stages in plant evolution
- Modern groups of plants
Timeline History of LIfe
Major Events in Evolution--onto land, into the air, going underground

T.P. Timeline of Life--class demo

Let a roll of toilet paper represent the four billion (4.0 B) year history of life on Earth
If the roll has 1000 sheets (Scott brand), then each sheet represents four million (4.0 M) years
If the roll has about 200 sheets (more typical smaller rolls), then each sheet represents 20 million (20.0 M) years
Here are some key events:

EVENT	TIME BEFORE PRESENT (BYA--billions of years ago (MYA--millions of years ago)	SHEET NUMBER ON THE TYPICAL ROLL
Formation and Solidification of Earth	4.6-4.0 BYA	1
Oldest Rocks Known	3.8 BYA	10
Earliest evidence of life--carbon forms in rock	3.8 BYA	10
Earliest fossil prokaryotic cells	3.5 BYA	25
Oxygen levels rise steeply due to increase in photosynthetic activity	2.5 BYA	75
Complex eukaryotic cells appear in fossil record	1.5 BYA	125
First multicellular organisms in fossil record	600 MYA	170
Burgess Shale--exposion of multicellular diversity--most multicellular animal groups represented in primitive form	515 MYA	176
First land vertebrates	350 MYA	183
Archaeopteryx--precursor to birds (and other dinosaurs)	150 MYA	192
End Cretaceous Extinction--goodbye dinos, hello mammalian, bird, flowering plant diversity	65 MYA	196
Lucy--Australopithecus	4 MYA	1 (last 1/4 of sheet)
Homo erectus, fire	1 MYA	1 (last 1/20 of sheet)
Start of agriculture, settlements	10,000-20,000 years ago	1 (last fibers)

Teaching notes for this activity [link]

Worsley school in Canada has a very nice page on the Toilet Paper Timeline

Elizabeth Roettger's page has a template for using a regular (250 sheet) roll of toilet paper to make a Toilet Paper Geologic Time Scale

Best Online Interactive Universe Timeline ever, from John Kyrk

MULTICELLULARITY

Multicellularity, and various mid-points, is common

An unrooted phylogenetic tree shows how multicellularity evolved independently in several eukaryotic lineages. The lineages are represented by branching lines. All of the lines are connected and radiate outward from the middle of the diagram. The taxa are represented by circles at the ends of the lines. The color of each circle indicates the taxon’s degree of multicellularity.