Transcript Student Presentation: Extinction

The
Accelerating
Loss of
Species:
The Sixth
Extinction
By: Mary A. Rodrigues
Mass
Extinctions
 A Mass Extinction is:

When at least half of all species (including animals and
plants) die within a relatively short time.
 We know these extinctions occurred


Through the fossil record
Fossils of plants and animals in early layers are suddenly
not present in later rock layers
 Scientists believe that 99% of all plant and animal species that have
ever lived are now extinct
The First Five Extinctions
 1st (Ordivician-Silurian) Extinction: 440 mya
 Caused by: sudden global cooliing
 Extinction of marine organisms
 2nd (Denovian) Extinction: 370 mya
 Caused by: possible climate change
 Extinction of tropical marine species
 3rd (Permian-Triassic) Extinction: 245 mya
 Caused by: climate change, plate tectonic movements,
 possible comet or meteor impact.
 largest mass extinction (so far)
 Killed a range of species, including vertebrates
 Only 10% of species survived
 4th (Triassic-Jurrasic)
Extinction: 210 mya


Unknown cause
Extinction of land vertebrates
 5th (Cretaceous-Tertiary)
Extinction: 65 mya





Caused by: collision of comet
or meteor and/or volcanic
eruption
Extinction of dinosaurs, marine
life, and many other plant and
animal species
50-75% of animals extinct
Global temperature decreased
Rise of the primates
How is the Sixth
Extinction Different?
 The sixth extinction is happening today
 All other mass extinctions were caused by
natural disasters, the sixth extinction is being
caused by modern humans
When did the Sixth
Extinction begin?
 When modern homo sapiens
began to radiate to different parts
of the world.
 Only in places where early
hominids lived, (Africa, Europe
and Asia) did native plant and
animal species survive in the
beginning.
 Some paleoanthropologists
believe that the Neanderthals
became extinct due to warfare or
competition from modern humans.
 Quickly after the arrival of
modern humans, native
species began to disappear.



North America – 12,500 years
ago
 Butchering killed off
mammoths, mastodons,
ancient buffalos
Caribbean – 8,000 years ago
 Lost all larger native
species
Madagascar – 2,000 years
ago
 Lost larger lemurs, elephant
birds, a species of hippo,
etc.
How are modern humans causing the
Sixth Extinction?
1.
2.
3.
4.
5.
Pollution
Warfare
Exploitation of
Species
Overpopulation
Unnatural Rates of
Consumption
6-Agriculture
“Single most profound ecological
change in the entire 3.5 billion
history of life”(Eldredge,N.)
- Pre-agricultural humans lived in niches in ecosystem and
worked with nature.
-Agriculture was invented 10,000-12,000 years ago in the
Middle East
- Agricultural humans live outside the natural
ecosystem.
-Accelerated rates of extinction
 Humans do not have to rely on other species for survival
 Humans do not have to rely on ecosystem’s carrying
capacity (how many species a local habitat can sustain)
Agriculture
(continued)
Results in:
Modern Humans living outside the natural
eco-system
Treating native plants as weeds
Treating native animals/insects as pests
The Sixth Extinction:
Specifics
 30,000 species are lost annually

(3 species an hour)
 Up to 1/5 of all living species could become extinct
within 30 years
 Nearly all loss is due to human activity

Mostly through the destruction of plant and animal
habitats
What can we do to help?
-get informed
-get involved
 http://www.well.com/~davidu/extinction.html
 http://en.wikipedia.org/wiki/Mass_extinction
 http://en.wikipedia.org/wiki/Sixth_extinction
 http://images.google.com
 http://www.amnh.org/exhibitions/dinosaurs/extinction/
mass.php
 Park, M. (2002). Biological anthropology. 3rd edition.
Boston:McGraw-Hill.
The Great Apes:
Their Battle Against Extinction
By: Angela Rodrigues
What is the Status of the Great Apes?
 Chimpanzees:
150, 000
 Bonobos: 50,000-100,000
 Gorillas: 130,000 (wild), 350
(captive)
Chimps, Bonobos, and Gorilla
Distribution: Africa
 Orangutans:12,000-15,000
remaining in Borneo
Orangutan Distribution: Asia
Chimpanzees/Bonobos:
Status: Endangered
1. Habitat Loss:

Fact: The only
true threat to
Great Apes are
humans
Human population increase;
Africa has highest growth rate
in world!
2. Biomedical Research:

Used as “models” for human
diseases; 99% similar DNA
3. Disease:


HIV
Ebola
4. Hunting:

Bushmeat Trade
Gorillas: Gorilla gorilla
Status: Critically Endangered
Threats:
1. Habitat Loss:

Deforestation-Competition for
natural resources
2. Disease:

Ebola
3. Poaching:


Not for food
Traps for other animals
Orangutan: Pongo pygmaeus
Status: Critically Endangered
1. Habitat Loss:


Palm Oil Plantations:
“Slash and Burn”-a process of
clearing areas for agriculture by
setting it on fire.
Logging: 80% is done illegally
2. Pet Trade


Infant’s mother killed to obtain baby.
4-5 orangutans die for every baby
reaching the market
3. Poaching

Bushmeat
Bushmeat Trade: #1 Threat
 Over 1 million metric tons of bushmeat are distributed per year in
Africa—not all are Great Apes, however.
 No longer is this done just by poor locals needing food/income; it is
becoming a commercial business
 40-60% of Africans rely on bushmeat for source of protein
 Not just a Great Ape problem; many endangered animals, such as
leopards and elephants, are also killed yearly.
What Does Their Future Hold?
Some Statistics:

For every 20,000 humans, there is one
chimpanzee

It is estimated that apes may become
extinct within the next generation

Some estimates even say that some
species may be extinct as soon as 5-10
years!

The bottom line: People need to be
educated about the seriousness of the
Great Ape Extinction
We started this extinction:
it is up to us to end it.
If we don’t help,
who will?
References:
1. Great Apes in Peril (2001). BBC World News. Retrieved May 1, 2006, from
http://news.bbc.co.uk/1/hi/sci/tech/1341609.stm
2. The BushMeat Trade (2005). Retrieved May 1, 2006, from
http://www.rainforestlive.org.uk
3. Chimpanzee Conservation (2006). The Jane Goodall Institute. Retrieved April 27, 2006,
from http://www.janegoodall.org/default.asp
4. Primate Info Net (2005). Retrieved April 26, 2006, from University of WisconsinMadison: http://pin.primate.wisc.edu/about.html
5. Orangutan Conservancy (2006). Retrieved April 26, 2006, from
http://www.orangutan.com/orangutans_threats.html
6. Great Ape Project (2006). Retrieved May 1, 2006, from http://en.wikipedia.org from
Wikipedia.
7. Threats to Gorillas (n.d.). Retrieved May 26, 2006, from
http://www.mountaingorillas.org/gorillas/gorillas_threats.htm
8. Park, M. (2005). Biological Anthropology (4th ed.). New York: McGraw-Hill Companies.