The Origins of Life: Other Ideas

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Transcript The Origins of Life: Other Ideas

Other ideas
Panspermia (aka cosmozoan)
Life came from somewhere else and
seeded Earth
The support for this depends up on
evidence that life exists elsewhere than on
and the evidence that it may travel through
open space
© 2008 Paul Billiet ODWS
Mars Viking Probe (1976)
revealed conflicting evidence
of life
Mariner Probe (1997) did not
reveal any more evidence
Tantalising evidence of water
on Mars
Venus has inhospitable
conditions (surface
temperatures of over
© 2008 Paul Billiet ODWS
Water and geothermal energy is the key
The moons of Jupiter
and Saturn could
provide the right
Europa appears to be
covered in ice
Io shows volcanic
Titan has organic
molecules present
© 2008 Paul Billiet ODWS
Life can survive in outer space
Bacteria, inadvertently left
on a lunar probe
Collected and cultured
successfully after nearly 2
years in space
Meteorites of Martian origin
show that its early
atmosphere would have
been similar to Earth’s early
They also showed
(debatable) evidence of
bacteria transported by
© 2008 Paul Billiet ODWS
Surveyor 3
Alien Earth
Life has been shown to
exist on Earth in very
inhospitable conditions
that could exist on
other planets
Antarctic dry valleys
Mid-ocean ridges
earth science australia
© 2008 Paul Billiet ODWS
Earliest evidence of life
The origin of the Earth itself is estimated as
4.5 billion years
Earliest evidence of life processes 3.9 billion
years ago
This leaves little time for biochemical
© 2008 Paul Billiet ODWS
The eternal question
If it can be shown that life came from an
extraterrestrial source the question still
How did life evolve in the first place?
© 2008 Paul Billiet ODWS
Special creation
The non-scientific hypothesis
Some supernatural being brought life into
existence from nothing
Literal interpretation of religious documents
9:00am on 23rd October 4004BC
© 2008 Paul Billiet ODWS
Intelligent Design
Creationists have tried to imply that life is so
complex and specialised that it could only
have come about through the design of a
supernatural creator
Once created it remained the same through
They accept microevolution
They reject the fact that new species can
come about by the natural selection of
chance mutations
© 2008 Paul Billiet ODWS
Special creation is based on belief
As these ideas are developed from a
theological view point they are impossible to
Creationists focus on trying to disprove the
theory of evolution rather than by testing their
own hypothesis
A scientific fact is an observation that has
been repeatedly confirmed and for practical
purposes is accepted as true
Special creation fails this criterion
© 2008 Paul Billiet ODWS