Evolution: Change Over Time

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Evolution Change Over Time
Evolution Change Over Time
The Evidence
The Evidence
Evolution Change Over Time
Evolution Change Over Time
The Evidence
The Evidence
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Fossil Record

• 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

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Comparing old fossils to modern life shows change
Ancient Kelp
Modern Kelp
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Radiometric Dating

• Helps determine age of fossils
• Isotopes atoms of the same element with
  differing neutrons
• Ex 12C and 14C
• 12C 6 protons 6 neutrons
• 14C 6 protons 8 neutrons
• When organism dies 14C starts to decay
• Fossil age determined by comparing ratio of 12C
  to 14C

Both are Carbon
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Timelines like this are accurate, but the scale
of time it too massive for us to visualizeSo
lets try a different scale of time
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24 Hour Life Timeline
Scale 1 minute 3 million years
This timeline shrinks Earths existence to a 24
hour day. We all can visualize 24 hours.
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Fossils show that the oldest life is 3.5
byobacteria
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24 Hour Life Timeline
Scale 1 minute 3 million years
Bacteria (3.5 billion)
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Fossils show the first vertebrates (fish) lived
510mya.
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24 Hour Life Timeline
Scale 1 minute 3 million years
Fish (510 million)
Bacteria (3.5 billion)
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Fossils show the first land animals (amphibians)
lived 340mya
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24 Hour Life Timeline
Scale 1 minute 3 million years
Amphibians (340 million)
Fish (510 million)
Bacteria (3.5 billion)
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Fossils show that reptiles first lived 310mya
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24 Hour Life Timeline
Reptiles (310 million)
Scale 1 minute 3 million years
Amphibians (340 million)
Fish (510 million)
Bacteria (3.5 billion)
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Fossils show that mammals and dinosaurs first
lived 250mya
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24 Hour Life Timeline
Dinosaurs mammals (250m)
Reptiles (310 million)
Scale 1 minute 3 million years
Amphibians (340 million)
Fish (510 million)
Bacteria (3.5 billion)
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Fossils show that flowering plants and birds
first lived 175mya
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24 Hour Life Timeline
Dinosaurs mammals (250m)
Reptiles (310 million)
Scale 1 minute 3 million years
Amphibians (340 million)
Flowers and birds (175 m)
Fish (510 million)
Bacteria (3.5 billion)
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Fossils show that humans first lived 200,000
years ago
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24 Hour Life Timeline
Dinosaurs mammals (250m)
Humans (200,000)
Reptiles (310 million)
Scale 1 minute 3 million years
Amphibians (340 million)
Flowers and birds (175 m)
Fish (510 million)
Bacteria (3.5 billion)
1 second 50,000 years So if humans have been
around for 200,000 years, how many seconds before
midnight did we evolve?
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Other Notable Events
Dinosaurs mammals (250m)
First plants (aquatic)
Reptiles (310 million)
Humans (200,000)
Obvious conclusion Life began very simple and
gradually became more complex
Scale 1 minute 3 million years
Amphibians (340 million)
Flowers and birds (175 m)
Fish (510 million)
Bacteria (3.5 billion)
Dinosaurs extinct
Unicellular eukaryotes
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Missing Link Fossils
Whale Evidence Long spine Found in dried up
oceans
Amphibian evidence Eyes on top of head Wrist
bones
Reptile Evidence Teeth Bony tail
Bird Evidence Wishbone Feathers
Land Evidence Wolf-like teeth Hind legs
Fish evidence Scales Fins Found in dried-up
oceans

• 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

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flipper
leg
wing
arm
Homologous Structures
walking
flight
grasping
swimming

• 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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Vestigial Structures

• 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

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Human Embryo w/ Vestigial Structures
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Pythons have tiny femurs (leg bone)
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Biochemical Evidence

• DNA, RNA, proteins compared
• Genetic code same for most life
• More related species have more similar
  biochemistry
• Evidence Conclusion Indicates common ancestry

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• Different species show similar development
  patterns
• Different body plans become noticeable later in
  development
• Evidence Conclusion Indicates common ancestry

Embryo Development
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• 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
Bacteria
Fungus
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Strong Survive
Most bacteria killed
Bacterial Resistance
Strong Reproduce
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Antibiotic Resistance
Good
Bad
The antibiotics kill the bacteria, so the area
around them are clear
The antibiotics dont kill the bacteria, thats
why there is no clear area around them.
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Pesticide Resistance
"crop dusting"

• 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

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Kobe Kuiz

• How does antibiotic and pesticide resistance show
  natural selection?
• How do the following lines of evidence show
  change over time?
• Fossils
• Homologous structures
• Vestigial structures
• Resistant organisms
• Embryo development
• Biochemical evidence
• Fossil age can be determined two ways. What are
  they?