1. What are the eras of the Phanerozoic? Name one important evolutionary event in each of those eras.
Paleozoic
The big incident of this era is the Cambrian explosion that happened 540 million years ago. Mesozoic
Angiosperms were diversified during this era Cenozoic
Mammals increase in size
2. Define/explain the following terms: Ediacaran, diagenesis, stromatolite, permineralized, Cambrian explosion, trace fossil, index fossil
The Ediacaran Period (pronunciation: Spans 94 million years from the end of the Cryogenian Period 635 million years ago (Mya), to the beginning of the Cambrian Period 541 …show more content…
Stromatolite; calcium depositing bacteria
Permineralized; minerals depositing in the cells of organisms where a clear fossil is produced
Cambrian explosition; a rapid expansion of animals in around 540 million years ago
Trace fossil; a remains of fingerprint, impression, foorprint, etcs
Uncomformity; when fossils in the same layer contains different groups of animals that supposed to have existed in different time zone.
3. What are some biases of the fossil record? (i.e. what causes some organisms to be more commonly fossilized than others?)
Fossils that contain a hard materials like teeth and bone are easily fossilized than soft tissue material
4. What is the difference between relative and absolute age in the
geological …show more content…
What are some similarities and differences between parsimony and maximum likelihood methods of phylogenetic tree reconstruction?
Similarity= both assume to minimize the total number of changes that occure
Difference= parsimony is for unrooted tree and maximum likelihood is for a rooted tree. Maximum likelihood explains how characters evolve and parsimony does not explain the evolution of characters.
7. What is meant by long-branch attraction?
One of the shortcoming of parsimony is long-branch attraction along with homoplasy. Long branch attraction is an assumption made in parsimony in which a rate of change along branches is similar. According to our lecture slide, this phenomenon is often is not true for a real data as there will be rate of change variations exist along branches resulting in potentially miss-grouping of species as sister taxa.
Example, in the following picture A and C has undergone a lot of changes along the branches which resulted in homoplasy and convergent evolution. Thus they are wrongly classified as sister taxon. Thus as the rate of change increases, opportunity for convergent evolution and homoplasy also increases. In reality, the sister taxon of A is b not C.
8.
Paleozoic
The big incident of this era is the Cambrian explosion that happened 540 million years ago. Mesozoic
Angiosperms were diversified during this era Cenozoic
Mammals increase in size
2. Define/explain the following terms: Ediacaran, diagenesis, stromatolite, permineralized, Cambrian explosion, trace fossil, index fossil
The Ediacaran Period (pronunciation: Spans 94 million years from the end of the Cryogenian Period 635 million years ago (Mya), to the beginning of the Cambrian Period 541 …show more content…
Stromatolite; calcium depositing bacteria
Permineralized; minerals depositing in the cells of organisms where a clear fossil is produced
Cambrian explosition; a rapid expansion of animals in around 540 million years ago
Trace fossil; a remains of fingerprint, impression, foorprint, etcs
Uncomformity; when fossils in the same layer contains different groups of animals that supposed to have existed in different time zone.
3. What are some biases of the fossil record? (i.e. what causes some organisms to be more commonly fossilized than others?)
Fossils that contain a hard materials like teeth and bone are easily fossilized than soft tissue material
4. What is the difference between relative and absolute age in the
geological …show more content…
What are some similarities and differences between parsimony and maximum likelihood methods of phylogenetic tree reconstruction?
Similarity= both assume to minimize the total number of changes that occure
Difference= parsimony is for unrooted tree and maximum likelihood is for a rooted tree. Maximum likelihood explains how characters evolve and parsimony does not explain the evolution of characters.
7. What is meant by long-branch attraction?
One of the shortcoming of parsimony is long-branch attraction along with homoplasy. Long branch attraction is an assumption made in parsimony in which a rate of change along branches is similar. According to our lecture slide, this phenomenon is often is not true for a real data as there will be rate of change variations exist along branches resulting in potentially miss-grouping of species as sister taxa.
Example, in the following picture A and C has undergone a lot of changes along the branches which resulted in homoplasy and convergent evolution. Thus they are wrongly classified as sister taxon. Thus as the rate of change increases, opportunity for convergent evolution and homoplasy also increases. In reality, the sister taxon of A is b not C.
8.