AP Biology Discussion Notes

Wednesday 11/18/2015

Goals for the Day1. Be able to describe & explain natural

selection & biological fitness

2. Be good AP readers & test takers!

11/18 Question of the Day

• What are some ways that one species could drive another to Extinction? (You could think about us or about other species.)

Evidence for EvolutionThe Tree of Life

• Is this theory saying that everything can be traced back to one common ancestor?

Your Questions

• How can one species have supposedly turned into another if there are still organisms from that species that still exist today? (Monkey’s “turned” into humans – monkeys still exist)

Your Questions

• How can one species have supposedly turned into another if there are still organisms from that species that still exist today? (Monkey’s “turned” into humans – monkeys still exist)

• Saying we shared a common ancestor..

Origin of Species

• Two Main Ideas– Natural Selection– Descent with Modification

Descent with Modification

• Descent -the fact or process of originating by generation from an ancestor

• Descent with modification all life comes from a common ancestor.

Evidence for Descent with Modification

• Fossil Record• Homologies

– Tree of Life– (Not chain of being)

The Fossil Record• Fossils provide an actual record of Earth’s

past life-forms and gives evidence that:

1. Earth is about 4.5 billion years old.

2. Organisms have inhabited Earth for most of its history.

3. All organisms living today share common ancestry with earlier, simpler life-forms.

Evidence for Natural Selection

• Fossil Record shows the– Succession of

Fossil forms

– Chronological appearance of vertebrates and other groups

Formation of Fossils

Why isn’t the fossil record complete?

Evidence for Descent with Modification

• Fossil Evidence– Cetaceans (Whales)– Whales are mammals,

unlike sharks which are fish !

• Tree of Life– Not chain of being

Evidence for Descent with Modification• Homologies – characteristics resulting

from common ancestry– Anatomical Homology– Embryological Homology– Molecular ( __ __ __ )Homology

How & why collect all of those animals?– To compare their structure and describe them.

Evidence for Descent with Modification• Anatomical Homologies – fore limbs of mammals have

the same bones, which have changed over time to adapt to different lifestyles of different organisms

Evidence for Descent with Modification• Embryological Homologies – development of vertebrates

is very similar in early stages

Evidence for Descent with Modification• Molecular Homologies

– All species of life use the same basic machinery (DNA & RNA)

• Used to build Molecular Phylogenies

Evidence for Descent with ModificationUsed to build Molecular Phylogenies

Evidence for Descent with ModificationUsed to build Molecular Phylogenies

Evidence for EvolutionMolecular Homologies

Used to build Molecular Phylogenies

Your Questions

• Is there any scientific evidence against natural selection? What are the theories, and are they convincing?

Your Questions• Are religion & evolution opposed to each

other – can you believe in both?

• What is behind nature?

• Is a theory saying all life is related “unreligious”?

CER – Evolution AP Questions• NO PHONES ALLOWED – REAL AP Qs

• Write question # and then write – C: – E:– R:

• The claim is the answer you are choosing, it does not have to be the first thing you write.

• Evidence – what supports your claim• Reasoning – why or how your evidence is

connected to your claim.

_______ 1. (32) I chose ___ as the answer to the question. (This is your claim.) Evidence: What evidence could you use to support your claim?  Birds and turtles both have lungs, but so do amphibians,

mammals, and lungfish Mammals do not share a direct common ancestor with

birds. Birds share a direct common ancestor with dinosaurs only. Reptiles, birds, and early mammals (i.e. platypus/echidna)

all lay amniotic eggs Crocodiles are not the direct descendent of ray-finned

fishes. Both lungfish and amphibians branch off much before crocodiles and after ray-finned fish.

 

_______ 1. (32) I chose __C_ as the answer to the question. (This is your claim.) 

•Reasoning: Tie your evidence back to your claim.•  Since reptiles, birds, and early mammals all

lay amniotic eggs the theory of evolution would suggest that is a trait from their common ancestor that these groups later diverged from.

CER – Evolution AP Questions• NO PHONES ALLOWED – REAL AP Qs

• Write question # and then write – C: – E:– R:

• The claim is the answer you are choosing, it does not have to be the first thing you write.

• Evidence – what supports your claim• Reasoning – why or how your evidence is

connected to your claim.

Looking Ahead

• Quiz on Chromatography Lab & Principles Friday 11/20– Will include water potential/diffusion questions

• 4th Reading Discussion – Thurs 12/03