Evolution And Classification Of Organisms

Question 1

Convergent evolution

Answer 1

Process whereby organisms not closely related independently evolve similar traits as a results of having to adapt to similar environments or ecological niches

Question 2

Adaptive radiation

Answer 2

Event in which a lineage rapidly diversifies and are adapted to specialised modes of life

Question 3

Monophyletic taxon:

Answer 3

includes the most recent common ancestor and all of its descendants

Question 4

Paraphyletic taxon

Answer 4

Includes last common ancestor but not all descendants

Question 5

Polyphyletic

Answer 5

does not include the common ancestor of all members of the taxon
– Usually indicates convergent evolution

Question 6

Cladistics: Plesiomorphy

Answer 6

An ancestral or primitive character state

Question 7

Cladistics:

– Symplesiomorphy (subterm of plesiomorphy)

Answer 7

• A character state shared by a number of groups, but inherited from ancestors older than the last common ancestor

Question 8

Apomorphy

Answer 8

A derived or specialised character state

Question 9

Automorphy (subterm of apomorphy)

Answer 9

Apomorphy unique to one group

Question 10

Synapomorphy

Answer 10

• Apomorphy shared by two or more groups which originated in their last common ancestor
• Shared derived character states in two taxonomic groups indicate that they are evolutionarily related

Question 11

Homoplasies (convergent evolution)

Answer 11

– Similar character states that evolved independently = parallel evolution or convergence
– Could be the result of adaptation to similar ecological niche/environment

Question 12

Systematics

Answer 12

Catalogue of organisms

Question 13

When was the publication of Charles Darwins ‘On the origin of species by means of natural selection’?

Answer 13

1859

Question 14

Darwin’s concept of evolution consists of…

Answer 14

1) Generation of random variation- varied population
2) Natural selection- competition, not all reproduce
3) combination of two- hereditary advantage= better chance to reproduce

Question 15

The Tree of Life shows that…

Answer 15

All life forms on earth are related

Question 16

Domains: the basic subdivision

Answer 16

Prokaryotes (w.o. nucleus)= (Eu)Bacteria and Archaea

-Eukaryota

Question 17

Which domains possibly share a common ancestor?/

Answer 17

Eukaryota and Archaea

Question 18

Four kingdoms of Eukaryotes

Answer 18

1) Protists
2) Plants
3) Fungi
4) Animals

Question 19

Supergroups of eukaryotes (SOE):

Archaeplastida (Plantae)

Answer 19

• glaucophytes, red algae green algae, land plants

- united by posession of a plastid derived from primary endosymbiosis

Question 20

Plastid

Answer 20

double membrane bound organelles found inside plant and some algae. Responsible for activities related to making and storing food.

Question 21

Endosymbiosis

Answer 21

Process where one cell is taken up by another and retained internally

Question 22

SOE: Excavata

Answer 22

-free living and symbiotic forms
-e.g parasites for humans
many lack classical mitochondria
-e.g. euglenoids, zooflagellates

Question 23

SOE: Chromalveolata

Answer 23

e. g. diatoms, brown algae, dinoflagellates

- widespread presence of plastids- derived from secondary endosymbiosis with red algae.

Question 24

SOE: Rhizaria

Answer 24

e.g. foraminifers, amoebae

Question 25

SOE: Unikonta

Answer 25

e.g. animals, choanoflagellates, fungi, slime molds, amoebes

Question 26

Taxonomy

Answer 26

Hierarchical classification system

Question 27

Phylogeny

Answer 27

Evolutionary relationships between organisms

Question 28

Evidence for phylogeny

Answer 28

• Comparative morphology – homologous and related structures
• Palaeontology –features in fossils vs similar features in extant species and other fossils – Isotope dating gives time scale
• Molecular biology – DNA and protein sequences
• Developmental Biology -> Evo-devo, embryo development

Question 29

Homologous

Answer 29

related by common descent

Question 30

Cladistics

Answer 30

Reconstruction of phylogenetic trees

Question 31

Clade

Answer 31

Organisms related through a common branch

Question 32

Why use scientific names?

Answer 32

-Vernacular names lack precision, language barriers, different scripts

Question 33

Requirements for scientific name…

Answer 33

1) “unknown to science”
2)collected and preserved
3)described- sufficient detail for
future recognition
4)location in Animal Kingdom determined-anatomy and gene sequences (?)
5)suitable name selected
6)type specimen in a museum for future reference

Question 34

ICZN- International code of zoological nomenclature (1901)

Answer 34

1) only one correct name
2) genus names =unique
3) Latin grammar rules
4) first name is used
5) type specimens must be nominated

Question 35

Proper use of scientific names

Answer 35

Capital & Italics= genus
Lower Case& italics= species
Brackets= Author

Question 36

Character states that are informative for the construction of phylogenetic trees…

Answer 36

Synapomorphies

Question 37

Character states that show similarity as a result of convergent evolution

Answer 37

Homoplasies

Question 38

A taxonomic group that includes all species derived from a unique, single ancestor is called

Answer 38

Monophyletic