1
00:00:37,487 --> 00:00:42,038
Many animals
have extreme physical powers.
2
00:00:42,087 --> 00:00:45,079
Some push their bodies to the limit.
3
00:00:45,127 --> 00:00:48,722
0thers tolerate
the harshest conditions on earth.
4
00:00:52,407 --> 00:00:57,356
Escaping a bush fire, a cheetah
is the fastest animal on foot.
5
00:01:00,247 --> 00:01:05,002
At 100 kilometres an hour,
its muscles are starved of oxygen,
6
00:01:05,047 --> 00:01:08,483
its temperature soars
to near lethal levels.
7
00:01:09,847 --> 00:01:12,566
Like other animals with extreme powers,
8
00:01:12,607 --> 00:01:15,599
it takes physical endurance to the edge.
9
00:01:27,367 --> 00:01:32,316
0n this journey, we explore the life
found in extreme environments.
10
00:01:33,367 --> 00:01:37,883
Microscopic life forms that can
endure harsh conditions in space
11
00:01:37,927 --> 00:01:40,316
often invade our homes.
12
00:01:41,727 --> 00:01:44,924
Riding the wind,
the spores of the pinhead fungus
13
00:01:44,967 --> 00:01:47,765
colonise almost every corner of earth.
14
00:01:53,407 --> 00:01:57,798
When they find perfect conditions,
they quickly exploit them.
15
00:02:00,927 --> 00:02:04,761
Invading mycelia reduce fruit to pulp.
16
00:02:11,287 --> 00:02:15,075
The next generation of spores
develops in just a few days.
17
00:02:15,127 --> 00:02:18,517
Housed in capsules, they wait for liftoff.
18
00:02:24,287 --> 00:02:28,075
Young money spiders
also tolerate extreme conditions.
19
00:02:28,127 --> 00:02:31,164
To disperse,
they climb to the highest points
20
00:02:31,207 --> 00:02:33,641
and wait for a gust of wind.
21
00:02:34,367 --> 00:02:37,518
(TV) T minus ten, nine, eight, seven,
22
00:02:37,567 --> 00:02:41,355
six, five, four, three,
23
00:02:41,407 --> 00:02:45,639
two, one, zero.
24
00:02:45,687 --> 00:02:47,803
Ignition.
25
00:02:47,847 --> 00:02:51,999
Liftoff. Liftoff 30 minutes after the hour.
26
00:02:59,127 --> 00:03:01,880
(Cat yowls)
27
00:03:11,247 --> 00:03:14,159
The spores and spiders
have begun a journey
28
00:03:14,207 --> 00:03:16,801
that will take them to new worlds.
29
00:03:27,887 --> 00:03:29,684
Buoyed by air currents,
30
00:03:29,727 --> 00:03:33,402
they´re transported
high into the atmosphere.
31
00:03:33,447 --> 00:03:38,043
Here, they´ll encounter some of
the most extreme environments.
32
00:03:45,327 --> 00:03:50,321
Higher forms of life also tolerate
these high-altitude conditions.
33
00:03:51,687 --> 00:03:54,155
The Himalayas.
34
00:03:58,447 --> 00:04:01,837
Ten kilometres up, no life should survive.
35
00:04:03,967 --> 00:04:07,676
Unidentified flying objects
demand investigation.
36
00:04:15,887 --> 00:04:19,084
(Geese honking)
37
00:04:22,727 --> 00:04:25,195
Migrating bar-headed geese
38
00:04:25,247 --> 00:04:30,275
ride the 200 kilometres-an-hour
winds that blow at this altitude.
39
00:04:36,607 --> 00:04:39,804
Here, pilots breathe pure oxygen.
40
00:04:39,847 --> 00:04:43,556
Geese extract their oxygen
from the thin air.
41
00:04:43,607 --> 00:04:46,360
0nce every second they take a breath.
42
00:04:46,407 --> 00:04:49,922
Each minute their heart pumps 400 times.
43
00:04:49,967 --> 00:04:53,596
Special blood cells
absorb every trace of oxygen.
44
00:04:54,687 --> 00:04:57,804
At minus 55,
only the heat from their exertion
45
00:04:57,847 --> 00:05:00,077
stops them freezing solid.
46
00:05:08,127 --> 00:05:10,402
Bar-heads breathe at high altitude
47
00:05:10,447 --> 00:05:13,405
more efficiently than any other bird.
48
00:05:19,167 --> 00:05:24,161
The ocean presents air-breathing
animals with a different extreme.
49
00:05:26,207 --> 00:05:28,801
Sea lions are natural divers.
50
00:05:28,847 --> 00:05:32,840
We push our bodies to the limit
in an effort to compete.
51
00:05:37,767 --> 00:05:42,636
Free divers meditate
to prepare for the challenge ahead.
52
00:05:47,327 --> 00:05:51,240
Ten metres down
and the pressure doubles.
53
00:05:57,607 --> 00:06:01,122
At 60 metres, the pressure
can squash the diver´s lungs
54
00:06:01,167 --> 00:06:04,125
enough to tear them from his ribcage.
55
00:06:04,167 --> 00:06:08,797
The sea lion´s chest is designed to collapse.
56
00:06:10,527 --> 00:06:15,157
Both man and sea lion lower
their metabolism to save oxygen
57
00:06:15,207 --> 00:06:19,120
and drop their heartbeats
to below ten a minute.
58
00:06:21,327 --> 00:06:25,115
The human depth record is 134 metres.
59
00:06:28,327 --> 00:06:30,761
Sea lions double this with ease.
60
00:06:30,807 --> 00:06:34,277
Their blood holds
five times more oxygen.
61
00:06:52,087 --> 00:06:57,241
2,000 metres down, squid
provide food for the elephant seal.
62
00:06:57,287 --> 00:07:01,678
It uses its two-ton body as a huge oxygen store
and can remain submerged for two hours.
63
00:07:05,327 --> 00:07:09,843
It stays active even though its heart
beats just four times a minute.
64
00:07:13,767 --> 00:07:16,327
The deepest diving mammal,
the sperm whale,
65
00:07:16,367 --> 00:07:19,757
reaches two and a half kilometres.
66
00:07:20,727 --> 00:07:24,083
Its lungs are proportionately
smaller than ours,
67
00:07:24,127 --> 00:07:27,324
but its muscles
act as a huge oxygen store.
68
00:07:29,287 --> 00:07:33,326
Four kilometres down, volcanic
vents erupt from the sea bed.
69
00:07:37,247 --> 00:07:40,557
These black smokers spew out toxic waste
70
00:07:40,607 --> 00:07:43,360
and yet life is found.
71
00:07:44,927 --> 00:07:47,885
Deep-sea shrimps graze bacteria
72
00:07:47,927 --> 00:07:51,044
that thrive near the superheated vents.
73
00:07:53,247 --> 00:07:56,796
Mats of bacteria harness heat
and chemical energy.
74
00:07:56,847 --> 00:08:02,126
The first forms of life, they survive
boiling and crushing pressures.
75
00:08:04,887 --> 00:08:07,196
Journey into the earth
76
00:08:07,247 --> 00:08:10,796
and we may find more bacteria
than at the surface.
77
00:08:23,487 --> 00:08:25,955
Three and a half kilometres down,
78
00:08:26,007 --> 00:08:29,238
bacteria are brought to light for the first time.
79
00:08:31,967 --> 00:08:34,561
Surviving huge pressures and heat,
80
00:08:34,607 --> 00:08:37,565
each individual can live for a thousand years.
81
00:08:37,607 --> 00:08:40,167
They eat nothing but rock.
82
00:08:44,287 --> 00:08:48,644
In this South African mine,
they also play a unique role.
83
00:08:52,927 --> 00:08:55,805
(Siren wails)
84
00:09:17,767 --> 00:09:21,157
Bacteria living here
are natural alchemists.
85
00:09:21,207 --> 00:09:23,801
They create deposits of gold.
86
00:09:25,127 --> 00:09:27,516
As they break down the mineral ores,
87
00:09:27,567 --> 00:09:31,446
the bacteria attract
molecules of gold to their surface.
88
00:09:31,487 --> 00:09:34,001
0ver millions of years, the gold builds up
89
00:09:34,047 --> 00:09:37,119
to form a glittering seam.
90
00:09:47,127 --> 00:09:50,756
The world of extremes
is also inhabited by fairies.
91
00:09:52,807 --> 00:09:54,923
(Echoing voices )
92
00:10:02,167 --> 00:10:05,796
Smaller than a grain of sand,
the eggs of the fairy shrimp
93
00:10:05,847 --> 00:10:09,476
may wait 10,000 years for life-giving water.
94
00:10:18,327 --> 00:10:21,046
They have evolved
to survive prolonged exposure
95
00:10:21,087 --> 00:10:24,124
to the intense heat of southern Africa.
96
00:10:26,327 --> 00:10:30,240
This must be their severest
test of survival.
97
00:10:33,327 --> 00:10:35,522
Besides their tough outer coating,
98
00:10:35,567 --> 00:10:40,163
the embryo´s cells are protected
by chemical heat shields.
99
00:11:03,687 --> 00:11:08,044
As the water cools, a miraculous
transformation begins.
100
00:11:11,047 --> 00:11:13,641
The fairies hatch.
101
00:11:14,727 --> 00:11:19,323
These crustaceans are the only
animals that can withstand boiling.
102
00:11:26,887 --> 00:11:29,560
This just-add-water technique
103
00:11:29,607 --> 00:11:32,075
allows the fairy shrimp to exploit pools
104
00:11:32,127 --> 00:11:35,244
that may appear only once every ten years.
105
00:11:40,727 --> 00:11:43,878
But predators, like the
prehistoric-looking Triops,
106
00:11:43,927 --> 00:11:46,725
also hatch from hard-boiled eggs.
107
00:11:46,767 --> 00:11:48,758
(Shouting)
108
00:11:51,447 --> 00:11:53,915
In the Middle East,
some plants are consumed
109
00:11:53,967 --> 00:11:56,356
by a different kind of heat.
110
00:11:59,407 --> 00:12:04,606
The aromatic cistus bush gives off
inflammable vapours in sunlight.
111
00:12:05,607 --> 00:12:08,280
0n still days, these shroud the plant,
112
00:12:08,327 --> 00:12:11,524
turning it into a living petrol bomb.
113
00:12:19,807 --> 00:12:22,116
0ne spark is enough to ignite.
114
00:12:46,687 --> 00:12:49,963
The bush may burn,
but so do its competitors.
115
00:12:50,007 --> 00:12:53,602
This clears the ground
for the next generation.
116
00:13:03,207 --> 00:13:08,076
As the seeds are freed, they crack
in the heat, ready for germination.
117
00:13:11,207 --> 00:13:14,165
The biblical story of
the burning bush may have arisen
118
00:13:14,207 --> 00:13:16,926
from this natural miracle.
119
00:13:23,007 --> 00:13:27,717
In Florida, there´s a creature
with a passion for fire.
120
00:13:37,207 --> 00:13:41,678
The fire beetle can sense infrared rays
beyond our visual range
121
00:13:41,727 --> 00:13:44,400
that are given off by forest fires.
122
00:14:01,807 --> 00:14:04,241
The signal radiates 80 kilometres,
123
00:14:04,287 --> 00:14:06,517
drawing the solitary beetles together
124
00:14:06,567 --> 00:14:09,161
to seek the source of the fire.
125
00:14:25,287 --> 00:14:28,882
As Florida´s Division of Forestry
dampens the inferno,
126
00:14:28,927 --> 00:14:33,239
the females´ scent inflames
the interest of the males.
127
00:14:47,527 --> 00:14:52,840
Spurred on by the females,
there´s hot competition to be first.
128
00:15:03,207 --> 00:15:05,721
The burnt wood is a vital prize.
129
00:15:05,767 --> 00:15:10,761
It´ll provide a home and food for
the next generation of fire beetles.
130
00:15:30,567 --> 00:15:34,355
Water can provide a refuge
from temperature extremes.
131
00:15:35,007 --> 00:15:36,998
While it´s there.
132
00:15:40,527 --> 00:15:44,918
Southern Africa is frequently
ravaged by severe droughts.
133
00:15:47,327 --> 00:15:51,764
For a fish out of water,
death is usually inevitable.
134
00:15:55,527 --> 00:15:58,519
But these fish
are not gulping air in vain.
135
00:15:58,567 --> 00:16:01,525
Their swim bladder forms a crude lung,
136
00:16:01,567 --> 00:16:05,560
allowing them to take in oxygen
directly from the air.
137
00:16:08,607 --> 00:16:12,236
The lungfish escapes the desiccating heat
by burrowing.
138
00:16:15,287 --> 00:16:18,040
It swallows the mud
to excavate a chamber,
139
00:16:18,087 --> 00:16:21,238
passing it out again through the gills.
140
00:16:25,807 --> 00:16:28,401
Then it coats itself in mucus.
141
00:16:32,887 --> 00:16:36,402
As the mucus dries,
it forms an impervious body bag
142
00:16:36,447 --> 00:16:39,757
that seals off the fish from the drought.
143
00:16:41,607 --> 00:16:45,077
River mud makes a secure
chamber for the lungfish,
144
00:16:45,127 --> 00:16:48,961
but it´s equally suitable for making bricks.
145
00:16:57,167 --> 00:16:59,522
As things go from bad to worse,
146
00:16:59,567 --> 00:17:04,083
the lungfish shuts down and waits
for conditions to improve.
147
00:17:09,367 --> 00:17:13,360
Central Australia also suffers
prolonged droughts.
148
00:17:15,407 --> 00:17:19,764
Beneath the dried lake bed,
other animals are buried alive.
149
00:17:25,287 --> 00:17:30,156
The desert frog can survive
entombed for seven years.
150
00:17:30,207 --> 00:17:33,005
It sheds layers of skin
that form a waterproof barrier
151
00:17:33,047 --> 00:17:35,845
which prevents the frog drying out.
152
00:17:39,447 --> 00:17:42,484
Above, the search for water continues.
153
00:17:44,687 --> 00:17:48,441
The thorny devil can survive
for years without drinking.
154
00:17:48,487 --> 00:17:53,481
Black ants provide all the moisture
it needs, and it eats nothing else.
155
00:18:14,367 --> 00:18:18,406
There are other ways
of quenching thirst in the desert.
156
00:18:46,407 --> 00:18:50,241
The frog´s bladder holds
a reservoir of drinking water,
157
00:18:50,287 --> 00:18:54,724
providing a good
emergency supply for Aborigines.
158
00:19:15,407 --> 00:19:17,682
In the desert, little is wasted.
159
00:19:19,887 --> 00:19:24,597
The thorny devil has a unique way
of collecting water.
160
00:19:24,647 --> 00:19:27,286
Capillary action.
161
00:19:28,047 --> 00:19:31,403
Its skin sucks up the liquid
like blotting paper.
162
00:19:34,047 --> 00:19:37,676
A darkening band traces the
water´s progress across the skin
163
00:19:37,727 --> 00:19:40,560
until it reaches the eyes and mouth.
164
00:19:43,247 --> 00:19:46,557
A network of channels
directs the water to the mouth.
165
00:19:50,527 --> 00:19:53,166
In this way, the lizards
drink the morning dew
166
00:19:53,207 --> 00:19:55,596
that forms on the desert sand.
167
00:20:04,327 --> 00:20:07,000
Even in Africa, droughts must end.
168
00:20:11,207 --> 00:20:15,723
The lungfish may wait four years
before the rainwater arrives
169
00:20:15,767 --> 00:20:18,884
to release it from suspended animation.
170
00:20:32,727 --> 00:20:34,718
By the end of the dormant period,
171
00:20:34,767 --> 00:20:38,362
the lungfish has started to process
its muscles as food.
172
00:20:41,207 --> 00:20:46,839
But enough power remains in them
to drag the fish back to water.
173
00:21:00,767 --> 00:21:05,079
Many animals use dormant periods
to escape extreme conditions,
174
00:21:05,127 --> 00:21:07,118
particularly the cold.
175
00:21:09,247 --> 00:21:12,956
In Manitoba, Canada,
thousands of red-sided garter snakes
176
00:21:13,007 --> 00:21:15,567
emerge from their winter hibernation.
177
00:21:18,247 --> 00:21:21,205
They live further north
than any other snake.
178
00:21:21,247 --> 00:21:24,523
The summers are short here,
and it´s a race to mate.
179
00:21:29,007 --> 00:21:31,726
The larger females
are overwhelmed by males
180
00:21:31,767 --> 00:21:34,645
which may outnumber them
a thousand to one.
181
00:21:34,687 --> 00:21:39,283
They live dangerously, for the
winter weather can quickly return.
182
00:21:41,167 --> 00:21:43,806
The drop in temperature
cools their passion
183
00:21:43,847 --> 00:21:48,523
and they race back to their dens
to escape the approaching freeze.
184
00:21:58,647 --> 00:22:02,686
Not all make it. Cold-blooded
reptiles become immobilised
185
00:22:02,727 --> 00:22:05,321
as the temperature drops.
186
00:22:06,367 --> 00:22:11,361
Trapped in an icy grip, the water
in their bodies starts to freeze.
187
00:22:15,927 --> 00:22:17,997
They turn into ice sculptures.
188
00:22:35,087 --> 00:22:39,399
With the dawn thaw,
a resurrection slowly begins.
189
00:22:49,087 --> 00:22:54,081
Red-sided garter snakes are the only
snakes that can survive freezing.
190
00:23:00,047 --> 00:23:02,800
While the rest of their bodies freeze solid,
191
00:23:02,847 --> 00:23:08,126
their vital organs are protected
by a natural antifreeze.
192
00:23:08,167 --> 00:23:11,796
The black stripes act as solar
panels to speed defrosting.
193
00:23:15,327 --> 00:23:20,526
Soon the heat of passion returns,
as the males risk the cold to mate.
194
00:23:27,127 --> 00:23:32,281
Even further north, the polar bear
regularly withstands minus 45 degrees,
195
00:23:32,327 --> 00:23:34,716
insulated by its thick coat.
196
00:23:40,367 --> 00:23:43,723
In a thermal image that depicts
temperature as colour,
197
00:23:43,767 --> 00:23:47,555
its coat is as blue
as the cold background.
198
00:23:47,607 --> 00:23:52,158
The bears show so little heat
escaping, they almost vanish.
199
00:23:55,447 --> 00:23:57,881
In late summer,
as they wait for the freeze,
200
00:23:57,927 --> 00:24:02,239
the bears are actually in danger of overheating.
201
00:24:16,007 --> 00:24:18,919
Protected by clothing, heat can only escape
202
00:24:18,967 --> 00:24:21,845
from the scientist´s face and hands.
203
00:24:23,447 --> 00:24:26,519
The bear leaks body heat
only from here too.
204
00:24:26,567 --> 00:24:30,845
It has such perfect insulation,
at rest it loses no more heat
205
00:24:30,887 --> 00:24:33,117
than a 200-watt light bulb does.
206
00:24:39,207 --> 00:24:41,596
Like the heat print
on the weather balloon,
207
00:24:41,647 --> 00:24:46,163
the only trace left by the bear
is a heat print on the ground.
208
00:24:47,927 --> 00:24:50,395
The bears have starved for six months,
209
00:24:50,447 --> 00:24:54,201
longer than any other
land mammal could tolerate.
210
00:24:55,927 --> 00:24:59,966
To survive, it conserves energy
by dropping its body temperature
211
00:25:00,007 --> 00:25:03,044
to levels lethal to us.
212
00:25:04,087 --> 00:25:06,965
If there´s a chance of a meal, they´ll take it.
213
00:25:10,007 --> 00:25:14,205
It can smell food from
as much as 30 kilometres away.
214
00:25:24,527 --> 00:25:26,961
The polar bear
is one of the few predators
215
00:25:27,007 --> 00:25:29,362
that will deliberately hunt a man.
216
00:25:50,087 --> 00:25:52,078
(Growling)
217
00:26:12,007 --> 00:26:15,920
Tripwires and flares
218
00:26:15,967 --> 00:26:17,958
prove their worth.
219
00:26:24,887 --> 00:26:29,324
Weather balloons probe
earth´s other coldest region.
220
00:26:29,367 --> 00:26:33,679
Five kilometres up, our money
spiders exploit high-altitude winds
221
00:26:33,727 --> 00:26:36,116
to continue their journey.
222
00:26:39,447 --> 00:26:42,598
At minus 30, ice forms over their surface,
223
00:26:42,647 --> 00:26:46,640
but their bodies are protected
by a natural antifreeze.
224
00:26:50,687 --> 00:26:53,804
80 kilometres up, above the ozone layer,
225
00:26:53,847 --> 00:26:56,998
our spores from the strawberries
survive extreme cold
226
00:26:57,047 --> 00:26:59,607
and damaging ultraviolet rays.
227
00:27:00,807 --> 00:27:04,004
Gravity has little effect
on these tiny spores,
228
00:27:04,047 --> 00:27:06,845
and, repelled by the earth´s electric field,
229
00:27:06,887 --> 00:27:09,321
they could be launched into space.
230
00:27:11,447 --> 00:27:14,803
In this infinite vacuum, it´s minus 90.
231
00:27:14,847 --> 00:27:17,839
0nly modern technology
can take us here.
232
00:27:20,407 --> 00:27:23,683
Although fungal spores
have yet to be recorded here,
233
00:27:23,727 --> 00:27:27,322
they are capable of surviving
these conditions.
234
00:27:27,367 --> 00:27:31,645
Living for 10,000 years, they make
the perfect space travellers
235
00:27:31,687 --> 00:27:34,076
to colonise new worlds.
236
00:27:40,487 --> 00:27:43,604
0n earth, with the change
in temperature and pressure,
237
00:27:43,647 --> 00:27:46,445
our defrosting spiderlings descend.
238
00:27:46,487 --> 00:27:50,480
They have crossed oceans
to settle in their new world.
239
00:27:53,247 --> 00:27:55,966
0ur quest for extraterrestrial life is helped
240
00:27:56,007 --> 00:28:00,125
by a growing understanding
of the earth´s extreme organisms.
241
00:28:01,407 --> 00:28:04,479
The harsh conditions these creatures endure
242
00:28:04,527 --> 00:28:08,361
make the probability of life in space a certainty.
243
00:28:21,207 --> 00:28:22,799
0n our next journey,
244
00:28:22,847 --> 00:28:26,840
Supernatural explores
the hidden forces of nature.
245
00:28:53,487 --> 00:28:55,478
(Geese honking)