1. Evolution Common Ancestry and Phylogeny Common Ancestry
Phylogenetic trees

2. Be able to
1.14 Pose scientific questions that identify essential properties of shared, core life processes that provide insights into the history of life on Earth.
1.15 Describe specific examples of conserved core biological processes and features shared by all domains or within one domain of life.
Explain how this is evidence for the common ancestry for all organisms.

3. Be able to
1.16 Justify the scientific claim that organisms share many conserved core processes and features that evolved and are widely distributed among organisms today

4. Evidence that all domains are related
Genetic information is encoded in DNA and RNA
These processes are identical within domains
e.g. all eukaryotes copy DNA the exact same way
Also very similar across domains
e.g. Bacterial DNA replication is similar to the eukaryotic process
🔗 DNA is the molecule of inheritance
Link: 3.A.1
Image: Wikipedia user C3lin

5. Evidence that all domains are related (cont.)
The Genetic code is universal
🔗 Evidence for evolution
🔗 Details in DNA chapter(s)
Link 1.A.4
Link: 3.A.1
User: Mouagip

6. Evidence that all domains are related (cont.)
Energy gets into and out of our cells in specific ways
🔗 Metabolic pathways
Many of these are exactly the same in every organism we have studied
🔗 Highly conserved
Ex. glycolysis occurs in nearly all organisms
Link: 2.A.1
Link: 3.D.1
glycolysis is the process turning sugar into pyruvate
exceptions include chemoautotroph, deep-sea vent bacteria

7. Evidence that all Eukaryotes are related
Cytoskeleton
structural proteins
facilitate cell movement
maintain shape
organelle transport
🔗 Details in cell structure chapter(s)
Present in all eukaryotes absent in prokaryotes
💬 Why does the structure of eukaryotes necessitate a cytoskeleton?
Link: 2.B.3; 4.A.2
Ans: The cell membrane itself is fragile, eukaryotes are complex and require transport and phago/exocytosis
Image:
Actin filaments are shown in red, microtubules are in green, and the nuclei are in blue.

8. Evidence that all Eukaryotes are related
All eukaryotic cells have membrane-bound organelles
💬 What does this mean?
Ans: All eukaryotic cells (plants, animals, etc) have subcellular components that are wrapped in their own membrane
Image: GrahamColm at English Wikipedia [GFDL ( or CC BY-SA 3.0 ( via Wikimedia Commons

9. Evidence that all Eukaryotes are related (cont.)
Mitochondria
found in most eukaryotic cells
essential for aerobic respiration
VERY similar to bacteria
Chloroplast
found in all plants and some algae
essential for photosynthesis
Very similar to bacteria
🔗 Details in cell structure chapter(s)
Link: 2.B.3; 4.A.2
mitochondria exceptions include Giardia lamblia an intestinal parasite which has evidence of mitochondria in its evolutionary history
Image: Louisa Howard

10. Evidence that all Eukaryotes are related (cont.)
Endosymbiosis
Theory that organelles of eukaryotes originated as a symbiotic relationship between single-celled organisms
one living inside the other
mitochondria (a single event) and chloroplasts (another, single event)
💬 What does it mean that it is a theory?
💬 What is the evidence?
Ans: That it is an explanation that has been verified, and that attempts to disprove it have failed
Ans: Many examples comparing the structure of these organelles to bacteria

11. Evidence that all Eukaryotes are related (cont.)
Eukaryotes have linear chromosomes, as opposed to the circular chromosomes found in prokaryotes
Image: National Institutes of Health
Image: Andrew S. Bajer

12. Evolution Common Ancestry and Phylogeny Common Ancestry
Phylogenetic trees

13. Be able to
1.17 Pose scientific questions about a group of organisms whose relatedness is described by a phylogenetic tree or cladogram in order to:
identify shared characteristics
make inferences about the evolutionary history of the group
identify character data that could extend or improve the phylogenetic tree

14. Be able to
1.18 Evaluate evidence provided by a data set, phylogenetic tree or cladogram to determine evolutionary history and speciation.
1.19 Create a phylogenetic tree or simple cladogram that correctly represents evolutionary history and speciation from a provided data set.

15. Phylogenetic trees and cladograms can represent traits
In the context of evolution
Model which traits are
derived
ex. 4 limbs in lizards, amphibians, birds, mammals
lost
ex. snakes’ legs

16. Phylogenetic trees and cladograms can represent traits (cont.)
Tuatara
Lizards
Snakes
Crocodiles
Bird
Cladogram of relationships of extant Sauria
What we call “lizards” includes multiple orders
Tuatara are found only in New Zealand and represent a distinct lineage
Image: Wikimedia: Benchill

17. Phylogenetic trees and cladograms illustrate speciation that has occurred
A and B share a common ancestor
The bottom of the chart points to a common ancestor for A through E A B C D E 1 2 3 4
Ans: D is more closely related to E
Ans: A and B are equally related to C
Image: Joshua Kaspar (CC-BY-SA)
💬 Is D more closely related to E or C?
💬 Is C more closely related to A or B?

18. Phylogenetic trees and cladograms illustrate speciation (cont.)B C D E 1 2 3 4 A B C D E 1 2 3 4
Image: Joshua Kaspar (CC-BY-SA)

19. They can be constructed from morphological similarities
Image:
"Cetacea-evolution" by Pakicetus_BW.jpg: Nobu Tamura ( Nobu Tamura ( Nobu TamuraProtocetus_BW.jpg: Nobu TamuraJanjucetus_BW_(mirrored).jpg: *Janjucetus_BW.jpg: Nobu Tamura work: Niusereset (talk)Squalodon_BW.jpg: Nobu Tamuraderivative work: Niusereset - This file was derived from:Pakicetus_BW.jpgAmbulocetus_BW.jpgKutchicetus_BW.jpgProtocetus_BW.jpgJanjucetus_BW_(mirrored).jpgSqualodon_BW.jpg. Licensed under Creative Commons Attribution-Share Alike 3.0 via Wikimedia Commons -

20. They can be constructed from morphological similarities (cont)
Image:
"Horseevolution" by Original uploader was Mcy jerry at en.wikipedia Later version(s) were uploaded by Obli at en.wikipedia. - Transferred from en.wikipedia. Licensed under Creative Commons Attribution-Share Alike 3.0 via Wikimedia Commons -

21. or from DNA and protein sequence similarities
Image:
"MyosinUnrootedTree" by T. Hodge and M.J.T.V. Cope - [ T. Hodge and M.J.T.V. Cope (2000). "A Myosin Family Tree". Journal of Cell Science 113: ]. Licensed under Creative Commons Attribution 1.0 via Wikimedia Commons -

22. These models are dynamic; based on current and emerging knowledge.
Ex. Scientists have agreed on the 3 domain system, but are researching and debating the number of kingdoms
Image:
Kingdom (biology). (2014, August 11). In Wikipedia, The Free Encyclopedia. Retrieved 03:20, September 3, 2014, from

23. These models are dynamic; based on current and emerging knowledge.
As our knowledge changes, so does our “tree of life.”
reflects our current understanding
💬 How is this like other scientific disciplines?
Ans: All scientific disciplines use models to represent current understanding, which change with new discoveries
Image: "Haeckel arbol bn". Licensed under Public domain via Wikimedia Commons -
Image: "Tree of life SVG" by Ivica Letunic: Iletunic. Retraced by Mariana Ruiz Villarreal: LadyofHats - The image was generated using iTOL: Interactive Tree Of Life, an online phylogenetic tree viewer and Tree Of Life resource. SVG retraced image from ITOL Tree of life.jpg[2]. Licensed under Public domain via Wikimedia Commons -
1866
2007