Post on 27-Jun-2020
C-Notes: Evidence of Evolution Stnd: 8 e
3/10/2014
Objective:
SWBAT analyze different types of evidence of evolution with regard to diversity of different organisms.
What evidence supports evolution?
1. Comparative Anatomy (Similar body structures)
2. Comparative Embryology (Patterns of early fetal development)
3. Comparative DNA/Molecular Biology (Similarities in DNA)
4. Fossils
**Conclusion: Things changed overtime and we all came from a Common Ancestor.**
What is comparative anatomy?
The study of the similarities and differences between the physical traits (genes) of different organisms. The more similar the anatomy, the more closely related the organisms are. Two Types: 1. Homologous structure 2. Vestigial Structure
How does comparative anatomy provide evidence that we evolved from a common ancestor?
Vertebrates all have similar bones, just shaped for their specific niches(habitat), which provides evidence that we are all related.
• Similar structures of the related species but different functions.
different shape but used for same thing
What are
homologous
structures?
What is ANALOGOUS Structures ?
Comparative Morphology = study of the forms/shapes of organisms.
HOMOLOGOUS Structures = same shape but different functions.
Comparative Morphology = study of the forms/shapes of organisms.
ANALOGOUS Structures = different shape but used for same thing.
What are Vestigial Structures?
Body part structures that you no longer use
Ex: wisdom teeth and appendix in humans. Whales hip bones is no longer attached to the spine or leg
How does vestigial structure provide evidence that we evolved from a common ancestor?
Shows the remainder of a body part that hasn’t completely been dissolved away
If it has no function, why is it there?
• Because it came from the common ancestor.
Vestigial organs = organs that are still present but
are no longer useful.
• Hind leg bones on whale fossils
Why would whales have pelvis & leg bones if they were always sea creatures?
Pelvis bone
What is Comparative Embryology (development)?
• Comparing how different species develop before birth.
• The more similar the development; the more closely related the organisms are
• Ex: Each develop a * tail *bud that becomes a limbs *pharyngeal pouches which contain gills
Comparative embryology =
• Development of embryo tells an evolutionary story
– similar structures during development
Human Fish Calf Salamander Hog Tortoise Rabbit chicken
1 2 3 4 5 6 7 8
Development of embryo tells an evolutionary story
They are later removed or develop into other structures.
How does comparative embryology provide evidence that we evolved from a common ancestor?
Shows that many organisms develop in a similar way, showing more evidence that we are related
What is Comparative DNA (Molecular Biology)?
• Comparing genes of different species to determine how closely related they are.
• The more similar the DNA sequences; the more closely related the organisms are
*Count the # of amino acids differences between the organisms. *The less differences the more closely related they are. • (ex: DNA, protein, etc.)
Which animal is more closely related to humans? How can you tell?
Animal Species
Amino Acid (Protein)
Difference Gorilla 1 Monkey 8 Mouse 27
Chicken 45 Frog 67
Lamprey 125
How does comparative DNA provide evidence that we evolved from a common ancestor?
The more similar the DNA sequences; the more closely related the organisms are
What are fossil records?
The remains or imprints of once-living organism found in layers of rock. (types of animal, location, age, etc) They provide clues to Earth’s past
lboeckl.net
Fossils = preserved remains of an
organism that lived many years ago.
www.greenriverstone.com
ngphotooftheday.blogspot.com
lovingthebigisland.wordpress.com
www.fossilmuseum.net
graphics8.nytimes.com images.icnetwork.co.uk
IDA: Revealing the Link http://www.revealingthelink.com/more-about-ida/the-film
What do we learn from fossils?
• Provides clues about how and when new species appeared, evolved, and became extinct.
• Look at similarities and differences in anatomy
Shows earlier forms of certain animals and transitional fossils. Look at similarities and differences in anatomy
Link between hoofed mammals and Whales 60 million years ago
Could walk like a sea lion But also swam 50 Million years ago
Spent little time on land, small hind legs useless for walking 40 Million years ago
Modern Whales have front flippers and small internal hind leg bones that do not have a function
Whale Evolution
What is gradualism?
• Idea that evolution occurs slowly but steadily
What is punctuated equilibria?
• Idea that evolution occurs quickly and is followed by long periods of little to no change.
• Explains gaps in fossil record.
http://www.youtube.com/watch?v=cC8k2Sb1oQ8