Transcript 440humanevdiv

Human Evolution
Human Evolution
I. What are humans related to?
Human Evolution
I. What are humans related to?
- Morphologically similar to apes
Human Evolution
I. What are humans related to?
- Morphologically similar to apes
- hands, binocular vision (Primates)
No tail
Human Evolution
I. What are humans related to? Apes
Human Evolution
I. What are humans related to? Apes
II. How do we differ?
Human Evolution
I. What are humans related to? Apes
II. How do we differ?
- Behaviorally (walk erect)
Human Evolution
I. What are humans related to? Apes
II. How do we differ?
- Behaviorally (walk erect)
- Behaviorally (intelligence and learning)
Human Evolution
I. What are humans related to? Apes
II. How do we differ?
- Behaviorally (walk erect)
- Behaviorally (intelligence and learning)
- Morphologically, humans have:
- larger head/body ratio
Human Evolution
I. What are humans related to? Apes
II. How do we differ?
- Behaviorally (walk erect)
- Behaviorally (intelligence and learning)
- Morphologically, humans have:
- larger head/body ratio
- smaller jaw/head ratio
Human Evolution
I. What are humans related to? Apes
II. How do we differ?
- Behaviorally (walk erect)
- Behaviorally (intelligence and learning)
- Morphologically, humans have:
- larger head/body ratio
- smaller jaw/head ratio
- shorter arms/body ratio
Human Evolution
I. What are humans related to? Apes
II. How do we differ?
- Behaviorally (walk erect)
- Behaviorally (intelligence and learning)
- Morphologically, humans have:
- larger head/body ratio
- smaller jaw/head ratio
- shorter arms/body ratio
- less hair
Human Evolution
I. What are humans related to? Apes
II. How do we differ?
- Morphologically
Human
Chimp Gorilla Orangutan Gibbon
Human Evolution
I. What are humans related to? Apes
II. How do we differ?
- Genetically: Big Surprize!
Human
Chimp Gorilla Orangutan Gibbon
Human Evolution
I. What are humans related to? Apes
II. How do we differ?
- Genetically: Big Surprize!
Human
Chimp Gorilla Orangutan Gibbon
< 1% difference
in gene sequence
Human Evolution
I. What are humans related to? Apes
II. How do we differ?
III. Resolution?
Can this 1% difference account for the dramatic
behavioral and morphological differences we see?
Human Evolution
I. What are humans related to? Apes
II. How do we differ?
III. Resolution?
Can this 1% difference account for the dramatic
behavioral and morphological differences we see?
Yes, some genes have big effects. These are
regulatory genes, acting during development. They
influence the expression of lots of other genes…
Human Evolution
I. What are humans related to? Apes
II. How do we differ?
III. Resolution?
Can this 1% difference account for the dramatic
behavioral and morphological differences we see?
Yes, some genes have big effects. These are
regulatory genes, acting during development. They
influence the expression of lots of other genes…
- Can we test this hypothesis? Do the differences
correlate with developmental effects?
- Yes. All differences correlate with developmental
differences between juvenile primates and adults…
Juveniles
Adults
Larger Head/body ratio
smaller
Smaller jaw/head ratio
larger
Shorter limb/body ratio
longer
Less hair
more hair
Better learning
poorer learning
- Yes. All differences correlate with developmental
differences between juvenile primates and adults…
Juveniles
Adults
Larger Head/body ratio
smaller
Smaller jaw/head ratio
larger
Shorter limb/body ratio
longer
- Yes. All differences correlate with developmental
differences between juvenile primates and adults…
Juveniles
Adults
Larger Head/body ratio
smaller
Smaller jaw/head ratio
larger
Shorter limb/body ratio
longer
Less hair
more hair
Better learning
poorer learning
Human-like
Ape-like
Human Evolution
I. What are humans related to? Apes
II. How do we differ?
III. Resolution?
Can this 1% difference account for the dramatic
behavioral and morphological differences we see?
Yes, if the small change is in developmental genes,
they can have BIG effects…humans might be a type
of ape that didn’t grow up…
The ways we differ supports this hypothesis…
Yes, if the small change is in developmental genes,
they can have BIG effects…humans might be a type
of ape that didn’t grow up…
Small changes in development, especially
if they occur early in development, can
result in big effects.
Human
Chimp
Primate developmental trajectory
What are some of these genetic differences?
The HAR1 RNA molecule.
- not a coding RNA; probably regulatory
Beniaminov A, Westhof E, and Krol A. 2008.
Distinctive structures between chimpanzee and human in a brain noncoding RNA. RNA
14:1270-1275.
What are some of these genetic differences?
The HAR1 RNA molecule.
- not a coding RNA; probably regulatory
- nearby genes associated with transcriptional
regulation and neurodevelopment are upregulated in
humans.
Beniaminov A, Westhof E, and Krol A. 2008.
Distinctive structures between chimpanzee and human in a brain noncoding RNA. RNA
14:1270-1275.
What are some of these genetic differences?
The HAR1 RNA molecule.
- not a coding RNA; probably regulatory
- nearby genes associated with transcriptional
regulation and neurodevelopment are upregulated in
humans.
- only 2 changes in sequence between chicks and
chimps; 18 between chimps and humans… “HAR”
stands for “human accelerated region” – changing
more rapidly than drift can explain… why? Selection.
Beniaminov A, Westhof E, and Krol A. 2008.
Distinctive structures between chimpanzee and human in a brain noncoding RNA. RNA
14:1270-1275.
What are some of these genetic differences?
The HAR1 RNA molecule.
- not a coding RNA; probably regulatory
- nearby genes associated with transcriptional
regulation and neurodevelopment are upregulated in
humans.
- only 2 changes in sequence between chicks and
chimps; 18 between chimps and humans… “HAR”
stands for “human accelerated region” – changing
more rapidly than drift can explain… why? Selection.
-Changes result in a profound change in RNA
structure and, presumably, binding efficiency.
Beniaminov A, Westhof E, and Krol A. 2008.
Distinctive structures between chimpanzee and human in a brain noncoding RNA. RNA
14:1270-1275.
Two distinct experimentally supported secondary structure models for HAR1 RNAs.
HUMAN
CHIMP
Beniaminov A et al. RNA 2008;14:1270-1275
Copyright © 2008 RNA Society
Human Evolution
I. What are humans related to? Apes
II. How do we differ?
III. Resolution?
IV. Are there common ancestors?
Human Evolution
I. What are humans related to? Apes
II. How do we differ?
III. Resolution?
IV. Are there common ancestors?
Yes. Just where evolution predicts they should be
(After other monkeys and apes, before humans and
existing apes).
Molecular clock analyses
Science, Nov 19, 2004
Pierolapithecus catalaunicus
12-13 mya: oldest ‘great ape’
‘apes’ – no tail
V. Are there common ancestors?
- Fossil and genetic analysis independently
predicted a common ancestor between humans and
chimps lived 5-8 million years ago.
Chimpanzee
Human
Homo sapiens
V. Are there common ancestors?
- Fossil and genetic analysis independently
predicted a common ancestor between humans and
chimps lived 5-8 million years ago.
Chimpanzee
Human
Sahelanthropus tchadensis – discovered in Chad in
2001. Dates to 6-7 mya. Only a skull. Is it on the
human line? Is it bipedal? Probably not (foramen
magnum). Primitive traits, as a common ancestor might
have.
Homo sapiens
Human Evolution
I. What are humans related to? Apes
II. How do we differ?
III. Resolution?
IV. Are there common ancestors?
V. Are there intermediate links to modern humans?
V. Are there intermediate links to modern humans?
- yes, and in a nearly continuous sequence….
Chimpanzee
Human
Homo sapiens
V. Are there intermediate links to modern humans?
- with a divergence of two types of hominids around 2 mya
V. Are there intermediate links to modern humans?
- with a divergence of two types of hominids around 2 mya
V. Are there intermediate links to modern humans?
- with a divergence of two types of hominids around 2 mya
“slender”
species
V. Are there intermediate links to modern humans?
- with a divergence of two types of hominids around 2 mya
“slender”
species
“robust”
species
V. Are there intermediate links to modern humans?
- with a divergence of two types of hominids around 2 mya
Primitive, bipedal species
Orrorin tugenensis: 5.6-6.2 mya. Discovered in 2000 by Brigitte Senut.
Processes on femus suggest bipedality in this forest-dwelling species,
refuting the savannah-bipedality link. Some suggest the femur is more
humanlike than those of Australopithecines, suggesting those are a side
group in human evolution.
Ardipithecus kadabba: 5.6 mya. Discovered in 2004 by Haile-Sailasse,
Gen Suwa, and Tim White. Initially thought to be chronospecies of A.
ramidus, tooth size in recent fossils suggested a new species.
Ardipithecus ramidus: 4.3-4.5 mya. Discovered in 1994 by Haile-Sailasse,
Suwa, and White, with the most complete fossils were not described until
2009. Arboreal, but facultatively bipedal. Grasping toes.
video
Australopithecus anamensis: 3.9-4.4 mya. About 100 fossils, from an
estimated 20 individuals; all from the Lake Turkana region of east Africa.
Found in 1965, 1987, 1995, and 2006, it was only in 1995 when Meave
Leakey distinguished it from other Australopithecine species. Probably the
direct ancestor of A. afarensis. Dr. Meave Leakey is spouse of Dr. Richard
Leakey, son of Louis and Mary Leakey – discoverers of several ancient
hominids at Olduvai Gorge.
Australopithecus afarensis: 2.8-3.9 mya. A femur discovered in 1973 by
Donald Johansson suggested an upright gait, confirmed by his discovery in 1974
of the ‘Lucy” specimen. Also, the Laetoli prints (found by Mary Leakey) were
probably made by A. afarensis, and in 2006, a juvenile A. afaresis was found.
And, as we’ve discussed, Australopithecus afarensis walked
erect.
video
And, as we’ve discussed, Australopithecus afarensis walked
erect.
A. Afarensis prints at Laetoli,
approximately 3.56 myr, were
made by an obligate biped:
- heel strike.
- Lateral transmission of force
from the heel to the base of the
lateral metatarsal.
- A well-developed medial
longitudinal arch.
- Adducted big toe, in front of the ball of the foot and parallel
to the other digits.
- A deep impression for the big toe commensurate with toe-off.
Australopithecus bahrelghazali: 3.6 mya; discovered in Chad in 1993 by
Michel Brunet – who won’t release it for others to study. Most paleontologists
suggest it is within the range of variation for A. afarensis. First australopithecine
outside of east Africa.
Kenyanthropus platyops: 3.2-3.5 mya – Discovered by Meave
Leakey’s team at Lake Turkana; most dispute it warrants another
genus, and some even include it in A. afarensis.
Australopithecus africanus: 2-3 mya, discovered by Raymond Dart in
South Africa in 1924 – the ‘Taung child’. Then, in 1947, Robert Broom
found a skull he classified as Plesianthropus, but was grouped with A.
africanus.
Australopithecus garhi: 2.5-2.6 mya; discovered by Asfaw and White in 1996,
but the skull below was discovered by Haile-Selasse in 1997. The tooth
morphology is a bit different from A. afarensis and A. africanus, being much
larger than even the robust forms. There are associated stone tools!
Australopithecus sebida: 1.9 mya, describe in 2010 by LE Berger; it has many
characteristics like A. africanus, but also similar to genus Homo.
Paranthropus aethiopicus: 2.5-2.7 mya, discovered by Alan Walker and
Richard Leakey, the “black skull” is one of the most imposing hominid
fossils there is! Aside from the high cheekbones and the sagittal crest, it
has similar proportions to A. afarensis and is probably a direct descendant.
It probably gave rise to the “robust” lineage of Paranthropus.
Paranthropus boisei: 1.2-2.6 mya. Discovered by Mary Leakey in Olduvai
Gorge in 1959, it was originally classified as Zinjanthropus and nicknamed
“Zinj” or “nutcracker man” because of the large grinding molars.
Paranthropus robustus: 1.2-2.0 mya. Discovered in South Africa in 1938
by Robert Broom.
Homo habilis: 1.4-2.3 mya, discovered by Louis and Mary Leakey, in
association with stone tools. “Handy man”. Longer arms and smaller brain than
other members of the genus.
Homo rudolphensis: 1.9 mya; Discovered by Richard and Meave Leakey’s team.
Different from H. habilis, yet a contemporary. Either may be ancestral to recent
Homo.
Homo georgicus: 1.7 mya; the oldest hominid fossils found outside of
Africa – found in Dmanisi, Georgia, in 1999. Thought to be a potential
intermediate between H. habilis and H. ergaster/H. erectus.
Homo erectus: 0.2-1.8 mya; originating in Africa, but then leaving for Asia
(Peking and Java Man). Discovered in Java by Eugene Dubois in 1891.
Certainly one of the most successful hominid species in history; perhaps lasting
as relictual species on islands in Indonesia as:
Homo floresiensis: 94,000-13,000 years,
discovered by Mike Mormood on the island of
Flores. Shoulder anatomy is reminiscent of H.
erectus, but could be an allometeric function
of the small size (3 ft).
Homo ergaster (H. erectus): 1.3-1.8 mya, the most
complete fossil hominid skeleton was discovered in 1984
by Alan Walker who called it “Turkana Boy”. Some
consider this species intermediate to H. habilis and H.
heidelbergensis/H. sapiens, leaving H. erectus as a
distinct Asian offshoot of the main line to H. sapiens.
However, most paleontologists suggest that H. ergaster
is the African ancestor – even a chronospecies or
population - of H. erectus, which is ancestral to more
recent Homo species.
Homo cepranensis: 350,000-500,000 years old; discovered by Italo Biddittu
in 1994 in Italy. It is just a skull cap, but seems to be intermediate between H.
erectus and H. heidelbergensis.
Homo antecessor: 800,000-1.2
mya; fossils from 20 individuals
found in Spain in 1994-5; may be H.
heidelbergensis or an intermediate
between it and H. ergaster.
Homo heidelbergensis: 250-600,000 in
Europe and Africa; ancestral to H.
neaderthalensis and H. sapiens; may
have buried their dead.
Homo rhodesiensis: 125-300,000; may
be H. heidelbergensis or intermediate to it
and H. sapiens.
Homo neaderthalensis: 30,000-150,000;
first discovered in 1829. Descended from
H. heidelbergensis.
Homo sapiens idaltu: 160,000 –
oldest Homo sapiens fossil – found
in Africa in 2003… Afar valley.
VIII. And what of our species?
- From Africa 200,000 years ago (earliest fossils, genetic
variability, etc.)
(Brazil)
(Brazil)
VIII. And what of our species?
- From Africa 200,000 years ago (earliest fossils, genetic
variability, etc.)
- Bands of hunter gatherers
VIII. And what of our species?
- From Africa 200,000 years ago (earliest fossils, genetic
variability, etc.)
- Bands of hunter gatherers
- Cave Art about 30,000 years ago
VIII. And what of our species?
- From Africa 200,000 years ago (earliest fossils, genetic
variability, etc.)
- Bands of hunter gatherers
- Cave Art about 30,000 years ago
- 14,000 years ago, bands settled in different areas of the
globe and began to grow local crops.
First Agricultural Revolution….
Where and when:
Fertile
Crescent
Eastern U. S.
Sahel?
Mesoamerica
Amazon?
Andes
West
Africa?
Ethiopia
?
China
New
Guinea
HUMAN PREHISTORY – Where did humans come from?
agricultur
e
burial
5.0
mya
75,000
14,000
99.6% before art
And Now…
The Anthropocene:
- 14,000 years to present.
Score of human impact due to land transformation,
soil, water, and air quality. (Each biome has it’s own
scale, however, so they are not explicitly
comparable).
“The pale blue dot” …. Earth from the Voyager spacecraft, > 4 billion miles away
http://solarsystem.nasa.gov/multimedia/display.cfm?IM_ID=2148
http://www.solstation.com/stars/earth.htm
http://nssdc.gsfc.nasa.gov/photo_gallery/photogallery-mars.html
http://www.thew2o.net/#
http://www.misterteacher.com/rainforestwebquest.html
CO2
N2
H2O
Ar
Earth
Mars
0.035%
77%
1%
0.93%
95%
2.7%
0.007%
1.6%
O2
http://www.misterteacher.com/rainforestwebquest.html
21%
trace
http://science.kennesaw.edu/~jdirnber/BioOceanography/Lectures/LecPhysicalOcean/LecPhysicalOcean.html
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
Earth History
4.5 million to present
(1/1000th of earth
history)
All genera
The “big five” Mass Extinction Events
Millions of Years Ago
http://en.wikipedia.org/wiki/File:Phanerozoic_biodiversity_blank_01.png
Thousands of Genera
“well described” genera
(% of Genera)
Permian mass extinction: 96% of all marine species and 70% of
terrestrial vertebrate species
WHY?
WHY?
WHY?
WHY?
WHY?
http://science.nationalgeographic.com/science/prehistoric-world/mass-extinction/
ecological
collapse
Almost all animals
over 25kg (~55 lbs)
went extinct.
(The things that require the most
energy to survive)
http://we.vub.ac.be/~dglg/Web/Claeys/Chicxulub/Chixproject.html
BIODIVERSITY NOW
http://www.coral.org/node/3230
Millenium Ecosystem Assessment (2006)
http://englishontour.blogspot.com/2011/03/beetles.html
http://www.illuminatedorigin.com/The_Illuminated_Origin_of_Species/Blog/Entries/2011/9/22_Beetles!.html
Detritivores
Pollinators
Insect predators
Herbivores
http://www.sbs.utexas.edu/jcabbott/abbottlab/
http://www.dendroboard.com/forum/photography/42636-incredible-costa-rican-euglossine-bees.html
Pollinators
Insect Parasitoids (lay eggs on other insects)
Insect Predators
http://magicbelles.com/flutterbudclub/special-wonders/beetles
Jewel Bug
Herbivores
Pollinators
Parasites
Detritivores
Malagasy Sunset Butterfly
http://www.brisbaneinsects.com/brisbane_flies/images/PWC_8410.jpg
http://buggirl.tumblr.com/post/12568644622/bugs-that-break-the-rules-themadagascar-sunset
http://www.trekearth.com/gallery/Africa/South_Africa/West/Eastern_Cape/Kob_Inn/photo915391.htm
Herbivores
Detritivores
http://www.flowersociety.org/Redwood-profile.htm
PRODUCERS
http://www.paulsanghera.com/infonential-Contact.html
Most vertebrate species are fishes
http://www.elp.manchester.ac.uk/pub_projects/2003/MNZO0MLK/lecture1.htm
http://ambergriscaye.com/critters/redeyedtreefrog.ht
ml
http://australian-animals.net/plat.htm
http://freakz.info/2011/09/21/10-interesting-seahorse-facts/
http://www.pbase.com/image/37557333
http://www.bbc.co.uk/nature/life/Blue_Whale
Herbivores, Predators, Detritivores, Pollinators
http://www.hodag.info/what%E2%80%99s-going-on-herethen-100
But do we
NEED all these
species??
There’s a lot of redundancy in nature…
http://katherinegerdes.com/portfolio/11/rainy-day-jewels
Are all species equally important? If not, which ones are critical?
with
without
We don’t know
which species
are critical
So we need to
save them all to
maintain
ecosystem
function
But what does
biodiversity
do??
1) Biodiversity increases “productivity” ... FOOD
Monoculture
They all need the same things at
the same concentrations; they
compete.
“Niche Complementarity”
Monoculture
Polyculture
They all need the same things at Combinations of different plants can be
the same concentrations; they
planted at higher density, and they use
compete.
different "niches" and coexist. Even if
abundance of "most productive" species
drops, this loss can be offset.
“Positive Effects”
Monoculture
They all need the same things at
the same concentrations; they
compete.
Polyculture
without
beans
with
beans
Nitrogen fixing legumes (beans) nutrify
the soil, increasing the growth of other
plants. And you have beans!
2) Biodiversity
improves
ecosystem
services
Estimates of various Ecosystem Services $U.S. trillions
Ecosystem services
Value
(trillion $US)
Soil formation
Recreation
Nutrient cycling
Water regulation and supply
Climate regulation
(temperature and
precipitation)
Habitat
Flood and storm protection
Food and raw materials
production
Genetic resources
Atmospheric gas balance
Pollination
All other services
Total value of ecosystem
services
17.1
3.0
2.3
2.3
1.8
1.4
1.1
0.8
0.8
0.7
0.4
1.6
33.3
Source: Adapted from R. Costanza et al., “The
Value of the World’s Ecosystem Services and
Natural Capital,” Nature, Vol. 387 (1997), p. 256,
Table 2.
TOTAL GLOBAL GNP (1997) = 18 trillion.
3) Aesthetics and
Inspiration: Biodiversity
enriches our cultures
3) Aesthetics and
Inspiration: Biodiversity
enriches our cultures
How is our biodiversity doing?
Genetic diversity within species
Species diversity in communities
Ecosystem diversity
How is our biodiversity doing?
Humans used hundreds of crop species worldwide;
now 3 species (rice, wheat, corn) provide 60% of our
calories from crop plants.
According to the FAO of the UN, 70% of the genetic
diversity of crop plants has been lost in the last 75
years as we’ve shifted to industrial farming and the
use of GM strains.
How is our biodiversity doing?
2000 Pacific Island bird species (15% of global total)
have gone extinct after human colonization
20 of the 297 mussel species in N.A. have gone
extinct in the last 100 years; 60% are endangered
40 of 950 fish species in N. A. have gone extinct in
the last century; 35% are threatened or endangered
http://www.americanscientist.org/issues/pub/the-real-biodiversity-crisis/1
Yellow-finned cutthroat trout
http://www.fishdecoys.net/pages/LDC_Collection/BenzieJoDecoys.htm
http://www.nps.gov/sacn/planyourvisit/st-croixcurrents.htm?customel_dataPageID_206517=289024
How is our biodiversity doing?
1 in 4 mammal species is endangered
1 in 8 bird species is endangered
1 in 3 amphibian species is endangered
48% of primate species are threatened
Data from: http://iucn.org/what/tpas/biodiversity/
How is our biodiversity doing?
35% of mangrove habitat has been lost in the
last 20 years
In the Caribbean, hard coral cover has declined
from 50% to 10% in the last 20 years
Since 2000, 232,000 sq miles of old growth
forest have been lost (size of Texas).
WHY?
7 billion in 2011 (12 years later)
http://news.mongabay.com/2011/1009-amazon_deforestation_revised.html
13,000 sq kilometers is about the size of Connecticut
Extent of Virgin Forest, Contiguous U. S.
http://mvh.sr.unh.edu/mvhinvestigations/old_growth_forests.htm
Millenium Assessment 2006
Humans use/control
40% of the ‘food’
produced on the
planet.
1
10 million?
Fragmentation
Fragmentation
Area Effects
CARNIVORES
HERBIVORES
PLANTS
LARGE AREA OF HABITAT
Fragmentation
HABITAT FRAGMENTATION
Fragmentation
1)Carnivores lost - (reduce diversity)
2)Herbivores compete – (reduce diversity)
3)Plants overgrazed – (reduce diversity)
HABITAT FRAGMENTATION
We are a geological force, operating
on an ecological timescale
Mountaintop removal in West Virginia
We are a geological force, operating
on an ecological timescale
Gold mining in Peruvian Amazon
We are a geological force, operating
on an ecological timescale
We are a geological force, operating
on an ecological timescale
We are a geological force, operating
on an ecological timescale
Hmmmm….
Sixth major mass extinction event - NOW
All genera
The “big five” Mass Extinction Events
Millions of Years Ago
http://en.wikipedia.org/wiki/File:Phanerozoic_biodiversity_blank_01.png
Thousands of Genera
“well described” genera
22 May 2010 –Secretary-General Ban Ki-moon:
“Biodiversity loss is moving ecological systems ever
closer to a tipping point beyond which they will no
longer be able to fulfill their vital functions.”
What Can We Do?
We need to protect and
preserve large intact,
biodiverse ecosystems.
This is great, but it ain’t gonna do it…
We need to rethink our model of community…
nature
nature
Development
Development
Development
Development
We need to find out what’s out there!
We need to appreciate the societal and
economic value of biodiversity
Corporate Social Responsibility (CSR)
http://www.justmeans.com/Stop-Loss-CSR-Biodiversity/28856.html
“Protection of biodiversity should be the underlying reason for every CSR
effort. Biodiversity loss is the most severe threat to human-wellbeing on the
planet. It rates even higher than climate change and related problems….
The head of Deutsche Bank's Global Markets predicts that our current rate of
biodiversity loss could see 6% of global GDP wiped out as early as 2050.
The Economics of Ecosystems and Biodiversity executive summary (2010)
reports that “over 50% of CEOs surveyed in Latin America and 45% in Africa
see declines in biodiversity as a challenge to business growth. In contrast, less
than 20% of their counterparts in Western Europe share such concerns”
If we recognize the grandeur of life, we might
appreciate it…
If we appreciate it, we might value it…
If we value it, we might sustain it…
If we sustain it, we might be able to sustain our societies
and economies, as well.
ECONOMY
SOCIETY
ENVIRONMENT
If we don’t, we won’t…
Thylacine - 1936
Tecopa Pupfish - 1981
Quogga - 1883
Vietnamese Rhinoceros - 2010
Yangtze River Dolphin - 2006
Golden Toad - 1989
A few extinct animal species.
Study questions:
In what two major ways does the earth differ from Mars?
How have each of these differences influenced the dramatic loss of CO2 from
the earth atmosphere, relative to Mars?
Dinosaurs went extinct because a meteor struck the earth and caused an
‘ecological catastrophe’ in which the animals with the greatest energy
demand went extinct. Why is humanity similarly vulnerable with respect to
the amount of resources we use, and the range of food we consume?
What are the two main ways that we are causing the extinction of other
organisms?
Why is maintaining diversity important?
(Brief answers on the next slides – try them yourselves first!!!!)
Study questions:
In what two major ways does the earth differ from Mars?
Lots of liquid water at the surface, and the presence of life.
How have each of these differences influenced the dramatic loss of CO2 from
the earth atmosphere, relative to Mars?
First, CO2 dissolves in water. Then, it is available to organisms that make
shells and reefs out of calcium carbonate. This material accumulates as
sedimentary deposits (Cliffs of Dover) in the lithosphere. Likewise, the
evolution of photosynthesis (specifically the ‘light independent reaction’)
allow CO2 in the atmosphere to be stored as glucose, cellulose, and other
organic molecules. Although respiration and decomposition would return
CO2 to the atmosphere, much of the organic remains have been preserved as
fossil fuel deposits in sedimentary rocks – again representing a transfer of
CO2 from the atmosphere to the lithosphere, mediated by living organisms.
Study questions:
Dinosaurs went extinct because a meteor struck the earth and caused an
‘ecological catastrophe’ in which the animals with the greatest energy
demand went extinct. Why is humanity similarly vulnerable with respect to
the amount of resources we use, and the range of food we consume?
We use 40% of the food produced on land. If there was an ecological
catastrophe that reduced food production, we would feel it worse than other
species. In addition, we get 60% of our calories from just three species!!!
So, if a calamity befalls any of these three species, we will feel it.
What are the three main ways that we are causing the extinction of other
organisms?
1. Competition – we are consuming most the food.
2. This is largely by changing their habitats (prairie, forest, etc.) into our
agricultural land.
3. Changing the climate faster than it has changed before, and faster than
many species can adapt.
Why is maintaining diversity important?
Study questions:
Why is maintaining diversity important?
Natural ecosystems provide ‘services’ upon which humanity depends, such
as making food, cleaning the air, cleaning the water, stabilizing the climate,
and fertilizing the soil. Ecology has shown that more diverse systems are
more effective and efficient at performing these functions. Although there is
redundancy in nature, we don’t yet know which species are the key ‘drivers’
of ecosystem function. As such, in order to maintain ecosystem function, we
must ‘keep all the pieces’. As the percentage of endangered species in
different groups shows, we aren’t doing such a great job at this.
BUT! The first step in solving a problem is identifying it. Now we know. Now
we must act.