Classifying Life and Reconstructing Phylogenies

Question 1

How do you turn phylogeny into a phylogenetic tree?

Answer 1

Need to plot it against geographical time

Question 2

What was the revolution in phylogenetics?

Answer 2

Phylogenetic analysis

AKA cladistic analysis

Question 3

How did cladistic analysis work?

Answer 3

1) Create a data metric of character states for the taxa under consideration

2) Use a computer package to analyse this data and create a cladogram

3) Creates a cladogram using the principles of parsimony or Bayesian methods

Question 4

What does analogous mean?

Answer 4

Organisms are similar due to convergent evolution (homoplasy)

Question 5

What does homologous mean?

Answer 5

Organisms have similarity due to common ancestors

Question 6

What does synplesiomorphis mean?

Answer 6

Organisms have shared ancestral characters

Question 7

What does synapomorphies mean?

Answer 7

Organisms have shared derived characters

Question 8

What does autapomorphies mean?

Answer 8

Organisms have characters that are unique to a taxon

Question 9

What type of group relationships are we searching for in phylogenies?

Answer 9

Sister group

Question 10

What is a monophyletic group?

Answer 10

Contains the latest common ancestor plus all, and ONLY all, of its descendants

This is what is used during taxonomy

Question 11

What is a paraphyletic group?

Answer 11

When one or more parts of a monophyletic group has been removed

Does not include all the descendants of a common ancestor

Question 12

What is a polyphyletic group?

Answer 12

When the most recent common ancestor is assigned to some other group and not the group itself.

Defined on the basis of convergence or non-homologous characters assumed to have been absent in the latest common ancestor

Question 13

What are the five kingdoms of life?

Answer 13

Animalia

Plantae

Fungi

Protista

Monera

Question 14

What can the kingdom, monera, be split into to create the eight kingdom system?

Answer 14

Bacteria (or eubacteria)

Archaea

Question 15

What are the factors of prokaryotes?

Answer 15

Bacteria or cyanobacteria

Generally 1-10um

Unicellular or colonial

Cell walls are made of particular sugars and peptides

Some have a flagella (made from flagellin protein)

No membrane-bound organelles

Anaerobic or facultative aerobic

Has a loop of DNA in the cytoplasm

Reproduce by binary fission

Dominantly asexual but some are parasexual

Question 16

What are some factors of eukaryotes?

Answer 16

Protists, fungi, plants, animals

Generally 10-100um

Mainly multicellular with tissues and organs (but protists are unicellular)

Cell walls are made of cellulose or chitin (lacking in animals)

Have flagella or cilia with microtubules

Have membrane-bound chloroplasts and mitochondria

Aerobic

DNA in chromosomes in membrane-bound nucleus

Have introns and exons

Reproduce by mitosis or meiosis

Dominantly sexual reproduction

Question 17

What is the sister group to eukaryotes?

Answer 17

Archaea