Transcript last lecture

The Human Disconnection
Questions
Does our species have the power to
shape the evolution of so many others?
Is biological evolution inseparable from
cultural change?
Human Impact on the Planet and
Other Life-Forms
The greatest challenges faced by humans
today is from the environments we’ve created
Human Population Growth
Humans and the Impact of
Culture
Human impact on the environment increased
dramatically when sedentary life developed
Increasingly exhausted nonrenewable
resources
Global Climate Change
Burning fossil fuels releases carbon dioxide,
which traps heat
Deforestation diminishes planet’s ability to
absorb excess carbon dioxide
Global Climate Change
Excess carbon dioxide contributes to acidification of
the oceans
Soon reaching levels not seen in 20 million years.
Diminishing marine biodiversity and food sources
Impact on Biodiversity
Humans now the “world’s greatest
evolutionary force”
History of Earth characterized by several
mass extinctions
The ongoing mass extinction caused by Homo
sapiens
Impact on Biodiversity
Hunting, introducing non-native species to new
environments and habitat reduction
Acceleration of Evolutionary
Processes
Human activities also accelerate evolutionary
processes for bacteria and viruses
Use of antibiotics led to evolution of resistant strains
DDT used to reduce mosquitoes, but also proved
disastrous to many bird species
Such cases make understanding evolutionary
relationships essential
Looking for Solutions
Most problems faced by humans are result of
our adaptive strategy gone awry
Many actions could be taken to curb the
negative effects
Is There Any Good News?
Population growth has slowed
Improvements in education reduce family size and
curb growth
Ecotourism represents compatibility of environmental
sustainability and economic growth
Some international cooperation has begun