Fig. 25-1 History of Life on Earth
Spontaneous Generation Prevailing theory before Pasteur Life arises spontaneously from nonlife
Redi disproves Spontaneous Generation Conclusion: flies from eggs from other flies
Lazzaro Spallanzani s 1700 s Experiment Why not widely supported? Others got bad results (contamination) Boiling destroyed vital principle for spont. Gen.
1860 s Pasteur Experiment
Early Earth Conditions Possible for: Abiotic organic molecule synthesis Macromolecule formation Protobionts formation Origins of self-replication First atmosphere: Water vapor nitrogen CO 2 CH NH3 H 2 H 2 S
Oparin & Haldane 1920 s Reducing atmosphere Energy from: Lighting Sunlight UV radiation Volcanoes Primitive soup
Fig. 4-2 Miller & Urey (1953) EXPERIMENT Water vapor CH 4 Atmosphere Electrode Condenser Cooled water containing organic molecules Cold water Jeffery Bada, Scripps 22 AA, 10 more H 2 O sea Sample for chemical analysis
Fig. 25-2 Aquatic vs atmospheric synthesis Water temperature (50C cooler ~ 100C) Stephan Fox (2009) salt crust
Relative turbidity, an index of vesicle number Protobionts 0.4 0.2 Precursor molecules plus montmorillonite clay Precursor molecules only 0 0 20 40 Time (minutes) 60 (a) Self-assembly 10 µm Vesicle boundary 1 µm (b) Reproduction (c) Absorption of RNA
Fig. 25-3 Protobionts 20 µm Glucose-phosphate Glucose-phosphate Phosphatase Phosphate Starch Maltose Amylase (a) Simple reproduction by liposomes Maltose (b) Simple metabolism What metabolic pathway does not require oxygen?
Cech & Altman (1980 s) Ribozymes genetic info & catalyzes different reactions RNA world hypothesis Ribozymes complementary RNA copies (short) How stable? How quickly replicated? RNA in vesicles protocells Template for DNA
Fossil Record (sedimentary layers) Limitations Dating & origins of new groups Present 100 mya 1 m Figure 25.5 Rhomaleosaurus victor 175 200 Dimetrodon 0.5 m 270 300 Tiktaalik Coccosteus cuspidatus 4.5 cm 375 400 Hallucigenia 1 cm Stromatolites 500 510 560 600 2.5 cm Dickinsonia costata 1,500 3,500 Tappania
Fig. 25-5 1 / 2 Accumulating daughter isotope Remaining parent isotope 1 / 4 1 / 8 1 /16 1 2 3 4 Time (half-lives)
OTHER TETRA- PODS Synapsids Therapsids Synapsid (300 mya) Dimetrodon Cynodonts Reptiles (including Figure 25.7 dinosaurs and birds) Very late (nonmammalian) cynodonts Mammals Key to skull bones Articular Quadrate Early cynodont (260 mya) Temporal fenestra (partial view) Hinge Later cynodont (220 mya) Dentary Squamosal Temporal fenestra Hinge Therapsid (280 mya) Original hinge New hinge Very late cynodont (195 mya) Temporal fenestra Hinge Hinge
Synapsid (300 mya) Temporal fenestra Figure 25.7b Key to skull bones Articular Quadrate Dentary Squamosal Hinge Therapsid (280 mya) Temporal fenestra Hinge
Early cynodont (260 mya) Temporal fenestra (partial view) Hinge Later cynodont (220 mya) Figure 25.7c Key to skull bones Articular Quadrate Dentary Squamosal Original hinge New hinge Very late cynodont (195 mya) Hinge
Table 25.1
Figure 25.8-1 Origin of solar system and Earth Hadean 4 Archaean 3 Prokaryotes Atmospheric oxygen
Fig. 25-4i Stromatolites 3.5 BYA, earliest prokaryotes
Fig. 25-4j Fossilized stromatolite
Fig 25-UN3 1 4 2 3 Atmospheric oxygen
(percent of present-day levels; log scale) 1,000 Figure 25.9 Atmospheric O 2 100 10 1 0.1 0.01 0.001 Oxygen revolution 0.0001 4 3 2 Time (billions of years ago) 1 0
Photosynthesis and the Oxygen Revolution Most atmospheric oxygen (O 2 ) is of biological origin Source of O 2? Cyanobacteria like bacteria Reacted with Fe oxides Posed a challenge for life Provided opportunity to gain energy from light Allowed organisms to exploit new ecosystems
Fig 25-UN5 1 4 2 3 Multicellular eukaryotes
Ancestral prokaryote Plasma membrane Cytoplasm DNA Endoplasmic reticulum Nuclear envelope Nucleus Autogenous Model for Eukaryotes Figure 25.10-1
Ancestral prokaryote Plasma membrane Cytoplasm DNA Endoplasmic reticulum Nucleus Engulfed aerobic bacterium Endosymbiosis & Eukaryotic Origins Nuclear envelope Figure 25.10-1
Ancestral prokaryote Plasma membrane Cytoplasm DNA Endoplasmic reticulum Nucleus Engulfed aerobic bacterium Endosymbiosis & Eukaryotic Origins Nuclear envelope Mitochondrion Ancestral heterotrophic eukaryote Figure 25.10-1
Cytoplasm DNA Endosymbiosis & Eukaryotic Origins Ancestral prokaryote Plasma membrane Endoplasmic reticulum Nuclear envelope Nucleus Engulfed aerobic bacterium Serial endosymbiosis Engulfed photosynthetic bacterium Mitochondrion Ancestral heterotrophic eukaryote 5 Evidence? Inner membrane similar plasma DNA structure Cell division Protein synthesis Ribosomes Ancestral photosynthetic eukaryote Mitochondrion Plastid Figure 25.10-1
Figure 25.8-2 Animals Origin of solar system and Earth 1 Proterozoic 4 Hadean Archaean Multicellular eukaryotes Single-celled eukaryotes 2 3 Prokaryotes Atmospheric oxygen
Figure 25.8-3 Humans Colonization of land Animals Origin of solar system and Earth 1 Proterozoic 4 Hadean Archaean Multicellular eukaryotes Single-celled eukaryotes 2 3 Prokaryotes Atmospheric oxygen
Fig 25-UN4 1 4 Singlecelled eukaryotes 2 3
Millions of years ago Sponges Cnidarians Echinoderms Chordates Brachiopods Annelids Molluscs Arthropods Fig. 25-10 Cambrian Explosion 500 Gould & Eldridge Punctuated Equilibrium Early Paleozoic era (Cambrian period) 542 Late Proterozoic eon
Cambrian Explosion Gould & Eldridge Punctuated Equilibrium Sponges Cnidarians Echinoderms Chordates Brachiopods Annelids Molluscs Arthropods PROTEROZOIC PALEOZOIC Ediacaran Cambrian 635 605 575 545 515 485 0 Time (millions of years ago) Figure 25.11
Fig. 25-11 Embryonic Cleavage? (a) Two-cell stage 150 µm (b) Later stage 200 µm
Fig 25-UN7 Colonization of land 1 4 2 3
Rise & Fall of Organisms 1) Continental drift 2) Mass extinctions 3) Adaptive radiation (speciation)
Fig. 25-12 & 25.13 1) Continental drift Crust Mantle Inner core Outer core (a) Cutaway view of Earth Juan de Fuca Plate Cocos Plate Pacific Plate North American Plate Caribbean Plate Nazca Plate South American Plate Scotia Plate (b) Major continental plates Arabian Plate African Plate Eurasian Plate Antarctic Plate Indian Plate Philippine Plate Australian Plate
Cenozoic Mesozoic Paleozoic Figure 25.16 Present 1) Continental drift Changes habitat 45 mya Collision of India with Eurasia Reduction in shallow water habitat Climatic changes on land Oceanic circulation 65.5 mya South America Eurasia Africa India Madagascar Present-day continents Allopatric speciation Antarctica 135 mya Laurasia Laurasia and Gondwana landmasses 251 mya The supercontinent Pangaea
Figure 25.19 Relative extinction rate of marine animal genera 3 Mass extinctions 2 1 0 1 2 3 2 1 0 1 2 3 4 Cooler Warmer Relative temperature
Total extinction rate (families per million years): Number of families: Fig. 25-17 5 Major Mass Extinctions 20 800 700 15 600 500 10 400 300 5 200 100 0 Era Period 542 Volcanoes eruptions Global warming Ocean acidification Decrease O2 in oceans Paleozoic Mesozoic E O S D C P Tr J 488 444 416 359 299 251 200 145 Time (millions of years ago) Cenozoic C P N 65.5 0 Meteors? Iridium 0
Fig. 25-18 Cretaceous mass extinction Yucatán Peninsula NORTH AMERICA Chicxulub crater
Predator genera (percentage of marine genera) Fig. 25-20 Mass Extinctions (alters ecological niches available) Adaptive radiation (especially predators) competition & selection 50 40 30 20 10 0 Era Paleozoic Mesozoic Cenozoic Period E O S D C P Tr J C P N 542 488 444 416 359 299 251 200 145 65.5 0 Time (millions of years ago)
Dinosaurs gone adaptive radiation of mammals Following mass extinctions Novel characteristics Colonization of new regions Ancestral mammal ANCESTRAL CYNODONT Monotremes (5 species) Marsupials (324 species) Eutherians (placental mammals; 5,010 species) 250 200 150 100 50 Millions of years ago 0 Fig. 25-21
Fig. 25-22 Adaptive Radiation - colonization Close North American relative, the tarweed Carlquistia muirii Dubautia laxa KAUAI 5.1 million years MOLOKAI 1.3 MAUI million years OAHU 3.7 LANAI million years HAWAII 0.4 million years Argyroxiphium sandwicense Dubautia waialealae Dubautia scabra Dubautia linearis
Fig. 25-23 Major changes in body form: 1) Heterochrony developmental rate or timing Newborn 2 5 15 Age (years) (a) Differential growth rates in a human Adult Chimpanzee fetus Chimpanzee adult Human fetus Human adult (b) Comparison of chimpanzee and human skull growth
Fig. 25-24 Major changes in body form 2) Paedomorphosis Timing (repro rate faster than body development Gills
Fig. 25-21 Major changes in body form 3) Spatial Pattern Homeotic genes (placement & organization of body parts) HOX genes (positional information) Hypothetical vertebrate ancestor (invertebrate) with a single Hox cluster First Hox duplication Hypothetical early vertebrates (jawless) with two Hox clusters Second Hox duplication Vertebrates (with jaws) with four Hox clusters
Figure 25.23 Changes in Spatial Pattern Homeotic genes (HOX)
Fig. 25-25 Changes in genes and gene regulation (timing & location) Hox gene 6 Hox gene 7 Hox gene 8 Ubx About 400 mya Drosophila Artemia
Fig. 25-26 Changes in genes regulation RESULTS Test of Hypothesis A: Differences in the coding sequence of the Pitx1 gene? Test of Hypothesis B: Differences in the regulation of expression of Pitx1? Marine stickleback embryo Result: No Result: Yes The 283 amino acids of the Pitx1 protein are identical. Pitx1 is expressed in the ventral spine and mouth regions of developing marine sticklebacks but only in the mouth region of developing lake stickbacks. Lake stickleback embryo Close-up of mouth Close-up of ventral surface
Figure 25.28 Evolutionary Novelties (a) Patch of pigmented cells (b) Eyecup Pigmented cells (photoreceptors) Epithelium Pigmented cells Nerve fibers Nerve fibers (c) Pinhole camera-type eye (d) Eye with primitive lens (e) Complex camera lens-type eye Epithelium Fluid-filled cavity Cellular mass (lens) Cornea Cornea Lens Optic nerve Example: Nautilus Pigmented layer (retina) Optic nerve Example: Murex, a marine snail Optic nerve Example: Loligo, a squid Retina
Eocene Oligocene Miocene Propalaeotherium Orohippus Pachynolophus Palaeotherium Epihippus Haplohippus Millions of years ago Miohippus Parahippus Sinohippus Megahippus Hypohippus Archaeohippus Hipparion Neohipparion Nannippus Hippidion and close relatives Callippus Holocene 0 Pleistocene Figure 25.29 Equus Pliocene 5 10 Pliohippus 15 Anchitherium 20 Merychippus 25 30 35 40 Mesohippus Grazers Browsers 45 50 55 Hyracotherium relatives Hyracotherium
Millions of years ago Eocene Propalaeotherium Orohippus Pachynolophus Palaeotherium Epihippus Haplohippus Oligocene Miohippus 25 30 Figure 25.29a Grazers Browsers 35 40 Mesohippus 45 50 55 Hyracotherium relatives Hyracotherium
Miohippus Millions of years ago Parahippus Miocene Sinohippus Megahippus Hypohippus Archaeohippus Hipparion Neohipparion Holocene 0 Pleistocene Pliocene 5 Figure 25.29b Equus Grazers Browsers 10 Pliohippus 15 Anchitherium 20 Merychippus 25
Table 25-1