Transcript The Diversity of Life I. An Overview II. An Overview of

The Diversity of Life
I. An Overview
The Diversity of Life
I. An Overview
A. Classifying Organisms
The Diversity of Life
I. An Overview
A. Classifying Organisms
Initially, using a Platonic,
typological concept, Linnaeus and
others created a nested, hierarchical
system.
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.
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.
The Diversity of Life
I. An Overview
Genus Felis
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 Panthera
Family Felidae
The Diversity of Life
I. An Overview
A. Classifying Organisms
B. Kingdoms
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').
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
The Diversity of Life
I. An Overview
A. Classifying
B. Kingdoms
C. Domains
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.
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
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.
The Diversity of Life
I. An Overview
A. Classifying
B. Kingdoms
C. Domains - "Ring of Life" hypothesis (2004)
The Diversity of Life
I. An Overview
4.5 bya: Earth Forms
D. Timeline
The Diversity of Life
I. An Overview
4.0 bya: Oldest Rocks
4.5 bya: Earth Forms
D. Timeline
4.0 bya: Oldest Rocks
3.5 bya: Oldest Fossils
4.5 bya: Earth Forms
The Diversity of Life
I. An Overview
D. Timeline
The Diversity of Life
I. An Overview
4.0 bya: Oldest Rocks
3.5 bya: Oldest Fossils
4.5 bya: Earth Forms
D. Timeline
Stromatolites - communities of layered 'bacteria'
2.3-2.0 bya: Oxygen in
Atmosphere
4.0 bya: Oldest Rocks
3.4 bya: Oldest Fossils
4.5 bya: Earth Forms
The Diversity of Life
I. An Overview
D. Timeline
1.8 bya: first eukaryote
2.3-2.0 bya: Oxygen
4.0 bya: Oldest Rocks
3.4 bya: Oldest Fossils
4.5 bya: Earth Forms
The Diversity of Life
I. An Overview
D. Timeline
0.9 bya: first animals
1.8 bya: first eukaryote
2.3-2.0 bya: Oxygen
4.0 bya: Oldest Rocks
3.4 bya: Oldest Fossils
4.5 bya: Earth Forms
The Diversity of Life
I. An Overview
D. Timeline
0.5 bya: Cambrian
0.9 bya: first animals
1.8 bya: first eukaryote
2.3-2.0 bya: Oxygen
4.0 bya: Oldest Rocks
3.4 bya: Oldest Fossils
4.5 bya: Earth Forms
The Diversity of Life
I. An Overview
D. Timeline
0.5 bya: Cambrian
0.24 bya:Mesozoic
0.9 bya: first animals
1.8 bya: first eukaryote
2.3-2.0 bya: Oxygen
4.0 bya: Oldest Rocks
3.4 bya: Oldest Fossils
4.5 bya: Earth Forms
The Diversity of Life
I. An Overview
D. Timeline
0.5 bya: Cambrian
0.24 bya:Mesozoic
0.065 bya:Cenozoic
0.9 bya: first animals
1.8 bya: first eukaryote
2.3-2.0 bya: Oxygen
4.0 bya: Oldest Rocks
3.4 bya: Oldest Fossils
4.5 bya: Earth Forms
The Diversity of Life
I. An Overview
D. Timeline
0.5 bya: Cambrian
0.24 bya:Mesozoic
0.065 bya:Cenozoic
0.9 bya: first animals
1.8 bya: first eukaryote
2.3-2.0 bya: Oxygen
4.0 bya: Oldest Rocks
3.4 bya: Oldest Fossils
4.5 bya: Earth Forms
The Diversity of Life
4.5 million to present
I. An Overview
D. Timeline
(1/1000th of earth
history)
The Diversity of Life
5 million to present
I. An Overview
0.5 bya: Cambrian
0.24 bya:Mesozoic
0.065 bya:Cenozoic
0.9 bya: first animals
1.8 bya: first eukaryote
2.3-2.0 bya: Oxygen
4.0 bya: Oldest Rocks
3.4 bya: Oldest Fossils
4.5 bya: Earth Forms
D. Timeline
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...
The Diversity of Life
I. An Overview
II. An Overview of 'The Bacteria'
The Diversity of Life
I. An Overview
II. An Overview of 'The Bacteria'
The Diversity of Life
I. An Overview
II. An Overview of 'The Bacteria'
The key thing about bacteria is their metabolic diversity. Although they
didn't radiate much morphologically (spheres, rod, spirals), they DID radiate
metabolically. As a group, they are the most metabolically diverse group of
organisms.
The Diversity of Life
I. An Overview
II. An Overview of 'The Bacteria'
The key thing about bacteria is their metabolic diversity. Although they
didn't radiate much morphologically (spheres, rod, spirals), they DID radiate
metabolically. As a group, they are the most metabolically diverse group of
organisms.
A. Oxygen Demand
all eukaryotes require oxygen.
The Diversity of Life
I. An Overview
II. An Overview of 'The Bacteria'
The key thing about bacteria is their metabolic diversity. Although they
didn't radiate much morphologically (spheres, rod, spirals), they DID radiate
metabolically. As a group, they are the most metabolically diverse group of
organisms.
A. Oxygen Demand
all eukaryotes require oxygen.
bacteria show greater variability:
- obligate anaerobes - die in presence of O2
- aerotolerant - don't die, but don't use O2
- facultative aerobes - can use O2, but don't need it
- obligate aerobes - require O2 to live
The Diversity of Life
I. An Overview
II. An Overview of 'The Bacteria'
The key thing about bacteria is their metabolic diversity. Although they
didn't radiate much morphologically (spheres, rod, spirals), they DID radiate
metabolically. As a group, they are the most metabolically diverse group of
organisms.
A. Oxygen Demand
all eukaryotes require oxygen.
bacteria show greater variability:
- obligate anaerobes - die in presence of O2
represents an interesting
continuum, perhaps
- aerotolerant - don't die, but don't use O2
correlating with the
- facultative aerobes - can use O2, but don't need it
presence of O2 in the
atmosphere.
- obligate aerobes - require O2 to live
The Diversity of Life
I. An Overview
II. An Overview of 'The Bacteria'
The key thing about bacteria is their metabolic diversity. Although they
didn't radiate much morphologically (spheres, rod, spirals), they DID radiate
metabolically. As a group, they are the most metabolically diverse group of
organisms.
B. Nutritional Categories:
The Diversity of Life
I. An Overview
II. An Overview of 'The Bacteria'
The key thing about bacteria is their metabolic diversity. Although they
didn't radiate much morphologically (spheres, rod, spirals), they DID radiate
metabolically. As a group, they are the most metabolically diverse group of
organisms.
B. Nutritional Categories:
- chemolithotrophs: use inorganics (H2S, etc.) as electron
donors for electron transport chains and use energy to fix carbon dioxide. Only
done by bacteria.
The Diversity of Life
I. An Overview
II. An Overview of 'The Bacteria'
The key thing about bacteria is their metabolic diversity. Although they
didn't radiate much morphologically (spheres, rod, spirals), they DID radiate
metabolically. As a group, they are the most metabolically diverse group of
organisms.
B. Nutritional Categories:
- chemolithotrophs: use inorganics (H2S, etc.) as electron
donors for electron transport chains and use energy to fix carbon dioxide. Only
done by bacteria.
- photoheterotrophs: use light as source of energy, but harvest
organics from environment. Only done by bacteria.
The Diversity of Life
I. An Overview
II. An Overview of 'The Bacteria'
The key thing about bacteria is their metabolic diversity. Although they
didn't radiate much morphologically (spheres, rod, spirals), they DID radiate
metabolically. As a group, they are the most metabolically diverse group of
organisms.
B. Nutritional Categories:
- chemolithotrophs: use inorganics (H2S, etc.) as electron
donors for electron transport chains and use energy to fix carbon dioxide. Only
done by bacteria.
- photoheterotrophs: use light as source of energy, but harvest
organics from environment. Only done by bacteria.
- photoautotrophs: use light as source of energy, and use this
energy to fix carbon dioxide. bacteria and some eukaryotes.
The Diversity of Life
I. An Overview
II. An Overview of 'The Bacteria'
The key thing about bacteria is their metabolic diversity. Although they
didn't radiate much morphologically (spheres, rod, spirals), they DID radiate
metabolically. As a group, they are the most metabolically diverse group of
organisms.
B. Nutritional Categories:
- chemolithotrophs: use inorganics (H2S, etc.) as electron
donors for electron transport chains and use energy to fix carbon dioxide. Only
done by bacteria.
- photoheterotrophs: use light as source of energy, but harvest
organics from environment. Only done by bacteria.
- photoautotrophs: use light as source of energy, and use this
energy to fix carbon dioxide. bacteria and some eukaryotes.
- chemoheterotrophs: get energy and carbon from organics
they consume. bacteria and some eukaryotes.
The Diversity of Life
I. An Overview
II. An Overview of 'The Bacteria'
The key thing about bacteria is their metabolic diversity. Although they
didn't radiate much morphologically (spheres, rod, spirals), they DID radiate
metabolically. As a group, they are the most metabolically diverse group of
organisms.
B. Nutritional Categories:
- chemolithotrophs: use inorganics (H2S, etc.) as electron
donors for electron transport chains and use energy to fix carbon dioxide. Only
done by bacteria.
- photoheterotrophs: use light as source of energy, but harvest
organics from environment. Only done by bacteria.
- photoautotrophs: use light as source of energy, and use this
energy to fix carbon dioxide. bacteria and some eukaryotes.
- chemoheterotrophs: get energy and carbon from organics
they consume. bacteria and some eukaryotes.
The Diversity of Life
I. An Overview
II. An Overview of 'The Bacteria'
The key thing about bacteria is their metabolic diversity. Although they
didn't radiate much morphologically (spheres, rod, spirals), they DID radiate
metabolically. As a group, they are the most metabolically diverse group of
organisms.
C. Their Ecological Importance
The Diversity of Life
I. An Overview
II. An Overview of 'The Bacteria'
The key thing about bacteria is their metabolic diversity. Although they
didn't radiate much morphologically (spheres, rod, spirals), they DID radiate
metabolically. As a group, they are the most metabolically diverse group of
organisms.
C. Their Ecological Importance
- major photosynthetic contributors (with protists and plants)
The Diversity of Life
I. An Overview
II. An Overview of 'The Bacteria'
The key thing about bacteria is their metabolic diversity. Although they
didn't radiate much morphologically (spheres, rod, spirals), they DID radiate
metabolically. As a group, they are the most metabolically diverse group of
organisms.
C. Their Ecological Importance
- major photosynthetic contributors (with protists and plants)
- the only organisms that fix nitrogen into biologically useful
forms that can be absorbed by plants.
The Diversity of Life
I. An Overview
II. An Overview of 'The Bacteria'
The key thing about bacteria is their metabolic diversity. Although they
didn't radiate much morphologically (spheres, rod, spirals), they DID radiate
metabolically. As a group, they are the most metabolically diverse group of
organisms.
C. Their Ecological Importance
- major photosynthetic contributors (with protists and plants)
- the only organisms that fix nitrogen into biologically useful
forms that can be absorbed by plants.
- primary decomposers (with fungi)
The Diversity of Life
I. An Overview
II. An Overview of 'The Bacteria'
The key thing about bacteria is their metabolic diversity. Although they
didn't radiate much morphologically (spheres, rod, spirals), they DID radiate
metabolically. As a group, they are the most metabolically diverse group of
organisms.
C. Their Ecological Importance
- major photosynthetic contributors (with protists and plants)
- the only organisms that fix nitrogen into biologically useful
forms that can be absorbed by plants.
- primary decomposers (with fungi)
- pathogens