The Diversity of Life

1
The Diversity of Life I. An Overview
2
The Diversity of Life I. An Overview A.
Classifying Organisms
3
The Diversity of Life I. An Overview A.
Classifying Organisms Initially, using a
Platonic, typological concept, Linnaeus and
others created a nested, hierarchical system.
4
The Diversity of Life I. An Overview A.
Classifying Organisms Initially, using a
Platonic, typological concept, Linnaeus and
others created a nested, hierarchical
system. Evolution explained this nested pattern
as a consequence of descent from common
ancestors.
5
The Diversity of Life I. An Overview A.
Classifying Organisms Initially, using a
Platonic, typological concept, Linnaeus and
others created a nested, hierarchical
system. Evolution explained this nested pattern
as a consequence of descent from common
ancestors. Modern biologists view the
classification system as a means of showing the
phylogenetic relationships among groups.
6
The Diversity of Life I. An Overview A.
Classifying Organisms Initially, using a
Platonic, typological concept, Linnaeus and
others created a nested, hierarchical
system. Evolution explained this nested pattern
as a consequence of descent from common
ancestors. Modern biologists view the
classification system as a means of showing the
phylogenetic relationships among groups. Genetic
relatedness should be the basic for biological
classification...
Genus Felis
Genus Panthera
Family Felidae
7
The Diversity of Life I. An Overview A.
Classifying Organisms B. Kingdoms
8
The Diversity of Life I. An Overview A.
Classifying Organisms B. Kingdoms
Phylogenetic analysis revealed that the "Monera"
were an incredibly diverse group genetically.
Also, one subgroup - the Archea, were more
similar to Eukaryotes than to the other group of
prokaryotes (the 'Eubacteria').
9
The Diversity of Life I. An Overview A.
Classifying Organisms B. Kingdoms
Phylogenetic analysis revealed that the "Monera"
were an incredibly diverse group genetically.
Also, one subgroup - the Archea, were more
similar to Eukaryotes than to the other group of
prokaryotes (the 'Eubacteria'). This required a
new way of looking at the most fundamental
groupings of life - and the introduction of a new
term Domains
10
The Diversity of Life I. An Overview A.
Classifying B. Kingdoms C. Domains
11
The Diversity of Life I. An Overview A.
Classifying B. Kingdoms C. Domains
Curiously, the very root of life may be invisible
to genetic analysis. Bacteria transfer genes by
division (to 'offspring'), but they also transfer
genes "laterally" to other living bacteria. This
makes reconstructing bacterial phylogenies
difficult.
12
The Diversity of Life I. An Overview A.
Classifying B. Kingdoms C. Domains
Also, early evolution involved bacterial
symbioses and gene sharing between hosts and
symbionts
13
The Diversity of Life I. An Overview A.
Classifying B. Kingdoms C. Domains
So, reconstructing the patterns of relatedness
among these ancient life forms is difficult.
14
The Diversity of Life I. An Overview D. Timeline
4.5 bya Earth Forms
15
The Diversity of Life I. An Overview D. Timeline
4.5 bya Earth Forms
4.0 bya Oldest Rocks
16
The Diversity of Life I. An Overview D. Timeline
4.5 bya Earth Forms
4.0 bya Oldest Rocks
3.8 bya Oldest Fossils
17
The Diversity of Life I. An Overview D. Timeline
4.5 bya Earth Forms
4.0 bya Oldest Rocks
3.8 bya Oldest Fossils
Stromatolites - communities of layered 'bacteria'
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The Diversity of Life I. An Overview D. Timeline
2.3-2.0 bya Oxygen in Atmosphere
4.5 bya Earth Forms
4.0 bya Oldest Rocks
3.8 bya Oldest Fossils
19
The Diversity of Life I. An Overview D. Timeline
2.3-2.0 bya Oxygen
1.8 bya first eukaryote
4.5 bya Earth Forms
4.0 bya Oldest Rocks
3.8 bya Oldest Fossils
20
The Diversity of Life I. An Overview D. Timeline
2.3-2.0 bya Oxygen
1.8 bya first eukaryote
0.9 bya first animals
4.5 bya Earth Forms
4.0 bya Oldest Rocks
3.8 bya Oldest Fossils
21
The Diversity of Life I. An Overview D. Timeline
2.3-2.0 bya Oxygen
1.8 bya first eukaryote
0.9 bya first animals
0.5 bya Cambrian
4.5 bya Earth Forms
4.0 bya Oldest Rocks
3.8 bya Oldest Fossils
22
The Diversity of Life I. An Overview D. Timeline
2.3-2.0 bya Oxygen
1.8 bya first eukaryote
0.9 bya first animals
0.5 bya Cambrian
0.24 byaMesozoic
4.5 bya Earth Forms
4.0 bya Oldest Rocks
3.8 bya Oldest Fossils
23
The Diversity of Life I. An Overview D. Timeline
2.3-2.0 bya Oxygen
1.8 bya first eukaryote
0.9 bya first animals
0.5 bya Cambrian
0.24 byaMesozoic
0.065 byaCenozoic
4.5 bya Earth Forms
4.0 bya Oldest Rocks
3.8 bya Oldest Fossils
24
The Diversity of Life I. An Overview D. Timeline
4.5 million to present
(1/1000th of earth history)
2.3-2.0 bya Oxygen
1.8 bya first eukaryote
0.9 bya first animals
0.5 bya Cambrian
0.24 byaMesozoic
0.065 byaCenozoic
4.5 bya Earth Forms
4.0 bya Oldest Rocks
3.8 bya Oldest Fossils
25
The Diversity of Life I. An Overview D. Timeline
5 million to present
2.3-2.0 bya Oxygen
1.8 bya first eukaryote
0.9 bya first animals
0.5 bya Cambrian
0.24 byaMesozoic
0.065 byaCenozoic
4.5 bya Earth Forms
4.0 bya Oldest Rocks
3.8 bya Oldest Fossils
for 1/2 of life's history, life was exclusively
bacterial.... what were they doing? Spheres,
rods, and spirals were all they could come up
with?? Let's look...