domain: archaea group: methanogens –methane releasing group: halophiles –lives in high salt...

Domain: Archaea

• Group: Methanogens– methane releasing

• Group: Halophiles– lives in high salt areas

• Group: Thermophiles– lives in extreme

temperatures

VirusesViruses

b

Virus Structure

Virus Structure• Capsid – Protein

coat covering virus; present in all viruses. Capsids are made from protein subunits called capsomeres.

• __________ – Layer of fat surrounding capsid; present in some viruses but not all.

Viral Replication• Only reproduce

when they enter a host cell

• They lack ribosomes and enzymes necessary for protein synthesis and simple metabolism

Viral Genome Structure

• dsDNA• ssDNA• dsRNA • ssRNA

– Serve as mRNA– Serve as template

for mRNA– Serve as template

for DNA (retro)

Bullet shaped envelope

HIV (a retrovirus)• Viruses that

causes AIDS• Peters Duesberg

______• ss RNA that can

serve as mRNA• Can cause paralysis

in motor neurons• Transmitted through

fecal contaminated food/water

• Worse in intermediately clean cities

• Salk vaccine, 1954

Hepatitis

• Inflammation of the liver

• At least 5 different types of the virus

• Hep A – ss RNA, no envelope; fecal-oral

• Hep C – ss RNA with envelope; sexually transmitted/ blood

__________• Bullet Shaped

Envelope (ss RNA)

• Long incubation period

• Almost always fatal if unvaccinated.

• Zoonosis• Host Range

Flu• Influenza, commonly

known as the flu• Symptoms include

fever, sore throat, myalgia, coughing, weakness

• Many Epidemic/

Episodes (1918-1919) 20-100 million died; Spanish Flu

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• Infectious Protein Particles

• Examples:• Mad Cow

Disease• Creutzfeldt-

Jakob Disease• Kuru (Fore tribe

of Papua New Guinea)

Cladistics

• ___________ – A type of chart showing the relationship of the different groups to one another.

• Clade – Any grouping on a cladogram that includes all of the descendents and a common ancestor.

• Sister Taxa

Cladistics• Shared ancestral

characters– ____________

• Shared derived characters– ____________

Cladistics• Outgroups – a clade

(species) closely related to the ingroup but less closely related than any of the ingroup members.

• Ingroups – The group we are trying to determine the relationships for.

• The Law of Parisimony (Occam’s Razor)

Cladistics Groupings• ___________ – Clade that includes ancestor and all

of its descendants.

• ____________ – Clade that includes ancestor and some, but not all, of it’s descendants.

• ____________ – Grouping that lacks a most recent common ancestor.

Data: AnatomyData: Anatomy

- Using similarities and differences (two kinds of similarities):

- _________ -likeness attributed to shared ancestry

Data: AnatomyData: Anatomy__________ - likeness

due to similar ecological roles and natural selection due to convergent evolution

Data: Molecular ComparisonsData: Molecular ComparisonsMolecular Homologies–

Comparing various molecules of different organisms. Many ways to do this…(Pg. 29 for example)

Data: Molecules as “clocks”

• Kimura, King• Neutral Theory• Molecular

Clocks

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Phylograms

Ultrametric Trees

Similar to a phylogram but all the branches that can be traced from the common ancestor to the present are of equal length. They do not imply evolutionary rates, but, they can place certain branching points in geological time.

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Fossil Record• __________ Rocks –

type of rock that usually makes best fossils

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Fossil Record

• Minerals replacing organic material

• Organic Material – when part of the organism remains

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Fossil Record• Casts –

impressions made by an organism

• Trace Fossils – footprints, burrows, or other signs of activity

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Fossil Record• Entire Organisms

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Limitations of the Fossil Record

• Habitat Bias – some habitat betters than others at making fossils

• Slow Decay – Some organisms decompose too quickly or get destroyed before fossilizing

• Temporal Bias – Time in which they lived and time of year.

• Common Bias – More common animals are more likely to fossilize if events are rare and somewhat random

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Dating FossilsAbsolute Dating (half-life)

Carbon -145,600 years

Carbon -145,600 years

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Relative Dating

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Data: Geology

New Rock – Sea floor spreading

Old Rock – Sea floor Disappearing

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Data: Geology

• Pangaea (245 mya)• Pangaea began to

break up (180 mya)– __________ (North)– __________ (South)

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Geological Time Scale

From here and down!

Comparing the genes or genomes of two species is the most direct measure of inheritance from shared ancestors. Comparisons can be made by using three methods: DNA-DNA hybridization, restriction maps, and DNA sequencing. Use the information to determine where species A through F belong in the phylogenetic tree. The information below is comparing the number of differences between an amino acid sequence from a blood protein found in rodents. (Assumption: The larger the number, the longer they have been separated from their common ancestor)

A B C D E F

A 0 10 4 9 14 10

B 10 0 11 5 16 2

C 4 11 0 10 15 10

D 9 5 10 0 15 6

E 14 16 15 15 0 16

F 10 2 10 6 16 0

CladogramPlace the taxa (outgroup, A, B, C, and D) on the

cladogram based on the presence or absence of the characters 1-4 as shown in this table. Indicate before each branch point, which shared derived character evolved in the ancestor of the clade.

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You are the first zoologist to penetrate the Timbasi Swamp and explore the Okongo Forest. You identify 7 new species of guenon monkeys. You collect blood sample and compare the new species blood proteins and facial markings to decide where on the current phylogenetic tree these new species belong. Match each of the new monkey species with one of the letters inserted into the revised phylogenetic tree. ____ 1. Ann’s: More closely related to Diana than any other species____ 2. Flat-topped: As close to Mona as Mona is to Campbell’s____ 3. Gladstone’s: Closer to redtail and moustached than any other new species____ 4. Bearded: Related to Diana but not as closely as Ann’s____ 5. Liebaert’s: A ground-dweller not closely related to any of the others____ 6. Perkins’s: Related to Mona and Campbell’s but it branched off earlier____ 7. Striped: Equally related to blue and redtail, but closer to ancestor