Transcript 24 Hour Life Timeline

• Defined: Collection of every
known fossil
• Most fossils found in
sedimentary rock
• Age determined by depth
– Law of Superposition: new
rock forms on top of older
rock
• Evidence Conclusions:
– 1) Newer fossils are more
complex
– 2) Common ancestors:
similarities between ancient &
modern life
Comparing old fossils to modern life
shows change
Ancient Kelp
Modern Kelp
Radiometric Dating
• Carbon Dating helps determine age of fossils
Timelines like this are accurate, but the scale of time it too massive for us
to visualize…So let’s try a different scale of time
24 Hour Life Timeline
Scale:
1 minute = 3 million years
This timeline shrinks Earth’s existence to a 24 hour day. We all can
visualize 24 hours.
Fossils show that the oldest life is
~3.5 byo…bacteria
24 Hour Life Timeline
Bacteria (3.5 billion)
Scale:
1 minute = 3 million years
Fossils show the first vertebrates
(fish) lived ~510mya.
24 Hour Life Timeline
Fish (510 million)
Bacteria (3.5 billion)
Scale:
1 minute = 3 million years
Fossils show the first land animals
(amphibians) lived ~340mya
Amphibians (340 million)
Fish (510 million)
Bacteria (3.5 billion)
24 Hour Life Timeline
Scale:
1 minute = 3 million years
Fossils show that reptiles first lived
~310mya
Amphibians (340 million)
Fish (510 million)
Scale:
1 minute = 3 million years
Reptiles (310 million)
Bacteria (3.5 billion)
24 Hour Life Timeline
Fossils show that mammals and
dinosaurs first lived ~250mya
Amphibians (340 million)
Fish (510 million)
Bacteria (3.5 billion)
Reptiles (310 million)
Scale:
1 minute = 3 million years
Dinosaurs & mammals (250m)
24 Hour Life Timeline
Fossils show that flowering plants and
birds first lived ~175mya
Amphibians (340 million)
Flowers and birds (175 m)
Fish (510 million)
Bacteria (3.5 billion)
Dinosaurs & mammals (250m)
Scale:
1 minute = 3 million years
Reptiles (310 million)
24 Hour Life Timeline
Fossils show that humans first lived
~200,000 years ago
Flowers and birds (175 m)
Amphibians (340 million)
Fish (510 million)
Humans (200,000)
Bacteria (3.5 billion)
Reptiles (310 million)
Scale:
1 minute = 3 million years
Dinosaurs & mammals (250m)
24 Hour Life Timeline
Dinosaurs extinct
Flowers and birds (175 m)
Amphibians (340 million)
Humans (200,000)
Fish (510 million)
Reptiles (310 million)
Unicellular
eukaryotes
Obvious conclusion:
Life began very simple
and gradually became
more complex
First plants (aquatic)
Bacteria (3.5 billion)
Scale:
1 minute = 3 million years
Dinosaurs & mammals (250m)
Other Notable Events
Cool Website
http://learn.genetics.utah.edu/content/variation/time/index2.html
Whale
Evidence
Reptile
Fish
evidence
Evidence
Long
Teeth spine
Scales
Amphibian
evidence
Land
Bird Evidence
Eyes on
top of head
Wolf-like
Wishbone
teeth
Found
in dried up
Bony tail
Fins
oceans
Found in dried-up
oceans
Wrist Hind
bones
Feathers
legs
• AKA: Transition Fossils
– Archaeopteryx: shares both bird & reptile features
– Basilosaurus: shares whale & land mammal features
– Tiktaalik: shares fish & amphibian features
• Evidence Conclusion : Indicates common ancestry
• Defined: Organs which have lost
most or all their original function
• Vestigial Human Parts:
– Gill slits = once used to breath
oxygen in water
– Yolk sac = once used to nourish
developing embryo
– Tailbone = once used for balance
– Appendix = once used to digest
plants
– Wisdom teeth = once used to
grind plant tissue
• Evidence Conclusion : Indicates
common ancestry
Human Embryo w/ Vestigial Structures
Pythons have tiny femurs (leg bone)
• Defined: similar body structures with very different
functions
• Different environments lead to adaptations
– Ex: The forelimbs of animals
• Evidence Conclusion : Indicates common ancestry
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DNA, RNA, proteins compared
Genetic code same for most life
More related species have more similar biochemistry
Evidence Conclusion : Indicates common ancestry
• Different
species show
similar
development
patterns
• Different body
plans become
noticeable later
in development
• Evidence
Conclusion :
Indicates
common
ancestry
Bacteria
Fungus
• Antibiotics: drugs
designed to kill bacteria
– Obtained from fungi
• Antibiotic Resistance:
Bacteria are adapting to
the use of antibiotics
– Misuse of antibiotics
speeds up the process
– Importance: Bacteria
infections are becoming
harder to treat
– Example of natural
selection
Antibiotic Resistance
Bad
The antibiotics don’t kill the bacteria, that’s
why there is no clear area around them.
Good
The antibiotics kill the bacteria, so
the area around them are clear
• Pesticides
– Chemicals designed to kill
pests (rodents, insects,
etc…)
– Pesticides sprayed on
crops to kill pests
• Pesticide Resistance: pests
are adapting to the use of
pesticides
– “Strong” pests survive to
reproduce
– Importance: Crops are
being destroyed by pests
– Great example of natural
selection
• How does antibiotic and pesticide resistance show natural
selection?
• How do the following lines of evidence show change over time?
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Fossils
Homologous structures
Vestigial structures
Resistant organisms
Embryo development
Biochemical evidence
• Fossil age can be determined two ways. What are they?