Life on a Young Planet (53 page)

NADPH,
86
–
87

Namacalathus
,
175
–
177
,
185
,
221

Nama Group,
162
–
165
,
170
–
171
,
173
–
175
,
221
; age of,
163
–
164
; fossils in,
162
,
164
–
167
,
171
,
172
–
177
,
plate 7

nanofossils,
232

nanometer,
142
,
230

natural selection,
11
,
13
,
18
,
72
,
80
,
83
–
85
,
87

nematodes,
180
,
186
–
187
,
194
,
204

nerves,
184

Newton, Isaac,
246

Nijman, Wouter,
57

Niklas, Karl,
115

nitrate (NO
₃
−),
20
,
22
,
101
,
159
–
160

nitrate reductase,
159

nitrogen,
22
–
23
,
75
,
159
,
241
; cycle of,
22
–
23
,
68
; fixation of,
23
,
111
,
159

North Pole, Australia,
50
–
51
,
56

nucleic acid(s),
72
,
79
,
81
–
84
,
87

nucleomorph,
129
–
130
nucleotide(s),
79

nucleus,
124
–
125
,
130
,
132
,
137
,
153
; putative fossils of,
143

Nursall, J. R.,
217

Ohmoto, Hiroshi,
98
,
103

Olenellus
,
plate 8

Olsen, Gary,
29

Oman,
221

ooid(s),
37
–
39
,
43
,
117

Opabinia
,
191
–
192

Oparin, Alexander,
74

Orakei Korako, New Zealand,
plate 1

Ordovician Period,
189
–
190
,
208

organs, in animals,
185

Oró, Juan,
79

Ovatoscutum
,
166

oxygen (O
₂
),
21
–
22
,
29
,
31
,
42
,
67
,
75
,
93
,
99
,
101
,
106
–
107
,
108
,
111
,
135
,
158
–
159
,
210
,
213
,
217
,
241
; in animal physiology,
217
–
218
; content of Archean atmosphere,
68
; cycle of,
103
–
104
; increase in early Proterozoic biosphere,
89
,
95
–
98
,
102
–
103
,
106
–
107
; increase in late Proterozoic biosphere,
139
,
157
–
159
,
206
,
218
–
219
,
223
–
224

Packer, Bonnie,
60

paleomagnetism,
210

paleontology,
4
,
35
,
49
,
65
,
188
,
193
,
206
,
218

parabasalids,
127

parasites,
134
–
135
,
232

Parvancorina
,
172

Pasteur, Louis,
72
,
73
,
123

Pauling, Linus,
23

peptide nucleic acid,
80

Peterson, Kevin,
202

Pflug, Hans,
165

Phanerozoic Eon,
2
,
9

phosphate: in
3
.8-billion-year-old rocks,
70
–
71
; fossiliferous,
139
–
141
,
144
–
146
,
149
,
162
,
180
,
plate 5
; in the origin of life,
79
,
82
; in skeletons,
185
,
189

phospholipid(s),
82
–
83

photosynthesis,
20
–
21
,
28
,
68
,
124
,
126
–
127
; bacterial,
28
; C-isotopic fractionation during,
46
–
48
; cyanobacterial,
103
; in eukaryotes,
123
–
124
,
126
–
131
,
159
; evolution of,
86
–
88

photosystem,
86

Phyllozoon
,
168

phylogeny,
19
,
23
–
28
,
30
; molecular,
23
–
24
,
132
,
183

pigment(s),
76
,
86

planets, extrasolar,
240

plants,
22
–
23
,
31
,
126
,
127
,
142
,
155
,
157
,
182
,
244

plasmodia,
138

plate tectonics,
38
–
39
,
67

Polybessurus bipartitus
,
40
–
41
,
110
,
117
,
plate 2

polycyclic aromatic hydrocarbons,
230

Popper, Karl,
234

Porifera,
180
,
194

Porter, Susannah,
150
–
151

Portuguese man-of-war,
169

potassium-argon, in geochronology,
54

Praecambridium
,
173

Prave, Tony,
214

Precambrian,
31

Precambrian-Cambrian boundary,
9
,
173
,
181
; environmental perturbation at,
206
,
219
–
220
,
222

predation,
139
,
156
,
184
–
185
,
222
–
223