benson pecha kucha
Post on 17-Jan-2015
537 Views
Preview:
DESCRIPTION
TRANSCRIPT
Life in the Universe
Alien life
forms?
Life has changed over time –
evolved.
New species have evolved…while some organisms have
hardly changed at all.
Stromatolite
Ancient trilobites & their present-day cousins, the chitons
Cockroaches Jurassic & Modern
Environmental Pressure & Survival of the Fittest
Horses – Eocene to modern
Requirements of life, (as we know it)
• Carbon-based molecules
• Energy source
• Water
DNA
Present in all of Earth’s life
forms
The Goldilocks Principle
“This porridge is too hot.”
“This porridge is too cold.”
“This is just right.”
Why does life exist on Earth ?
• Life began here • Life traveled here from other worlds - exogenesis
Exogenesis – Did life travel here from a distant world?
top related