Download presentation
Presentation is loading. Please wait.
1
AP Biology Big Idea 1: Part D
Natural Processes and the Origin of Living Systems: Hypothesis and evidence of these origins: 4.1, 25.1, 25.3 Scientific evidence from many disciplines: 26.6
2
Concept 4.1: Organic chemistry is the study of carbon compounds
Organic chemistry is the study of compounds that contain carbon Organic compounds range from simple molecules to colossal ones Most organic compounds contain hydrogen atoms in addition to carbon atoms Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
3
Vitalism, the idea that organic compounds arise only in organisms, was disproved when chemists synthesized these compounds Mechanism is the view that all natural phenomena are governed by physical and chemical laws
4
Sample for chemical analysis
Fig. 4-2 EXPERIMENT “Atmosphere” CH4 Water vapor Electrode NH3 H2 Condenser Cooled water containing organic molecules Cold water Figure 4.2 Can organic molecules form under conditions believed to simulate those on the early Earth? H2O “sea” Sample for chemical analysis
5
Concept 26.6: New information continues to revise our understanding of the tree of life
Recently, we have gained insight into the very deepest branches of the tree of life through molecular systematics
6
From Two Kingdoms to Three Domains
Early taxonomists classified all species as either plants or animals Later, five kingdoms were recognized: Monera (prokaryotes), Protista, Plantae, Fungi, and Animalia More recently, the three-domain system has been adopted: Bacteria, Archaea, and Eukarya The three-domain system is supported by data from many sequenced genomes Animation: Classification Schemes
7
EUKARYA BACTERIA ARCHAEA Fig. 26-21 Land plants Dinoflagellates
Green algae Forams Ciliates Diatoms Red algae Amoebas Cellular slime molds Euglena Trypanosomes Animals Leishmania Fungi Sulfolobus Green nonsulfur bacteria Thermophiles (Mitochondrion) Figure The three domains of life Spirochetes Halophiles Chlamydia COMMON ANCESTOR OF ALL LIFE Green sulfur bacteria BACTERIA Methanobacterium Cyanobacteria ARCHAEA (Plastids, including chloroplasts)
8
BACTERIA Green nonsulfur bacteria (Mitochondrion) Spirochetes
Fig a Green nonsulfur bacteria (Mitochondrion) Spirochetes Chlamydia COMMON ANCESTOR OF ALL LIFE Green sulfur bacteria Figure The three domains of life BACTERIA Cyanobacteria (Plastids, including chloroplasts)
9
ARCHAEA Sulfolobus Thermophiles Halophiles Methanobacterium
Fig b Sulfolobus Thermophiles Halophiles Figure The three domains of life Methanobacterium ARCHAEA
10
EUKARYA Dinoflagellates Land plants Forams Ciliates Red algae Amoebas
Fig c EUKARYA Land plants Dinoflagellates Green algae Forams Ciliates Diatoms Red algae Amoebas Cellular slime molds Euglena Trypanosomes Animals Leishmania Figure The three domains of life Fungi
11
A Simple Tree of All Life
The tree of life suggests that eukaryotes and archaea are more closely related to each other than to bacteria The tree of life is based largely on rRNA genes, as these have evolved slowly
12
There have been substantial interchanges of genes between organisms in different domains
Horizontal gene transfer is the movement of genes from one genome to another Horizontal gene transfer complicates efforts to build a tree of life
13
Bacteria Eukarya Archaea 4 3 2 1 Billions of years ago Fig. 26-22
Figure The role of horizontal gene transfer in the history of life 4 3 2 1 Billions of years ago
14
Is the Tree of Life Really a Ring?
Some researchers suggest that eukaryotes arose as an endosymbiosis between a bacterium and archaean If so, early evolutionary relationships might be better depicted by a ring of life instead of a tree of life
15
Fig Eukarya Bacteria Archaea Figure A ring of life
16
Node Taxon A Taxon B Sister taxa Taxon C Taxon D Taxon E Most recent
Fig. 26-UN2 Node Taxon A Taxon B Sister taxa Taxon C Taxon D Taxon E Most recent common ancestor Polytomy Taxon F
17
Monophyletic group A A A B B B C C C D D D E E E F F F G G G
Fig. 26-UN3 Monophyletic group A A A B B B C C C D D D E E E F F F G G G Paraphyletic group Polyphyletic group
18
Fig. 26-UN4 Salamander Lizard Goat Human
19
Fig. 26-UN5
20
Fig. 26-UN6
21
Fig. 26-UN7
22
Fig. 26-UN8
23
Fig. 26-UN9
24
Fig. 26-UN10
25
Fig. 26-UN10a
26
Fig. 26-UN10b
27
You should now be able to:
Explain the justification for taxonomy based on a PhyloCode Explain the importance of distinguishing between homology and analogy Distinguish between the following terms: monophyletic, paraphyletic, and polyphyletic groups; shared ancestral and shared derived characters; orthologous and paralogous genes Define horizontal gene transfer and explain how it complicates phylogenetic trees Explain molecular clocks and discuss their limitations
Similar presentations
