Unit 5

5.1 Evidence for Evolution

Understanding

• U1 Evolution occurs when heritable characteristics of species change.

• U2 The fossil record provides evidence for evolution.

• U3 Selective breeding of domesticated animals shows that artificial selection can cause evolution.

• U4 Evolution of homologous structures by adaptive radiation explains similarities in structure when there are differences in function.

• U5 Populations of a species can gradually diverge into separate species by evolution.

• U6 Continuous variation across the geographical range of related populations matches the concept of gradual divergence

Application

A1 Development of melanistic insects in polluted areas.

1. melanistic - dark variation of a common-lifght form of an organism

2. Peppered Moth (Bisto betulania) is usually light

3. darker variation appeared in 1800s England due to the industrial revolution

4. Peppered Moths are nocturnal

   1. unpollutued trees have light lichens to blend in

   2. polluted trees have soot and sulfur dioxide (SO₂) poisoning the lichens

5. melanistic moths were better camouflaged

6. birds and other predators hunted the peppered moths

7. melanistic moths continued breeding

A2 Comparison of the pentadactyl limb of mammals, birds, amphibians, and reptiles with different methods of locomotion.

Bat: the pentadactyl limb becomes its wing (used for flying)

Porpoise: the pentadactyl limb becomes its fin (used for swimming)

Human: the pentadactyl limb becomes its hand (used for holding)

Mole: the pentadactyl limb becomes its claw (used for digging)

Anteater: the pentadactyl limb becomes its paw (used for crawling)

Horse: the pentadactyl limb becomes its leg (used for moving)

Nature of Science

NOS 1 Looking for patterns, trends and discrepancies- there are common features in the bone structure of vertebrate limbs despite their varied use.

5.2 Natural Selection

Understanding

• U1 Natural selection can only occur if there is variation among members of the same species.

• U2 Mutation, meiosis and sexual reproduction cause variation between individuals in a species.

• U3 Adaptations are characteristics that make an individual suited to its environment and way of life.

• U4 Species tend to produce more offspring than the environment can support.

• U5 Individuals that are better adapted tend to survive and produce more offspring while the less well adapted tend to die or produce fewer offspring.

• U6 Individuals that reproduce pass on characteristics to their offspring.

• U7 Natural selection increases the frequency of characteristics that make individuals better adapted and decreases the frequency of other characteristics leading to changes within the species.

Application

A1 Changes in beaks of finches on Daphne Major.

1. Daphne Major is in the Galapagos Archipelago

2. the Medium Ground Finch (Geospiza fortis) feed on seeds of all sizes

3. larger seed = harder shell = bigger beak

4. Beak Size is heritable

5. to study their beaks, in 1973 they were barred from leaving

6. Galapagos Archipelago has varying climate

   1. El Niño brings heavy rains

   2. La Niña brings droughts

7. heavy rains = small seeds but droughts = big seeds

8. 1974-77 had a severe drought

9. bigger beaks better adapted = # of bigger beaks increased = mean beak size increased

10. when temps normalized, there were still more bigger beaks as they kept breeding

11. in 1983, El Niño raised temps = more small seeds = small more small beaks

A2 Evolution of antibiotic resistance in bacteria.

• Antibiotics are used to control diseases caused by bacteria in humans.

• some pathogens are becoming resistant to antibiotics

  • ex: pathogens susceptible to ciprofoxacin between 1990 and 2004.

Theory of Natural Selection explains the following:

1. Microorganisms that create antibiotics also contain genes that resist that antibiotic (or else they would be killed by the substance, duh)

2. pathogens can get a hold of the genes (plasmid transfer, etc.)

3. some pathogens have the gene, others don’t

4. antibiotics will only kill bacteria without the gene

5. resistant pathogens survive and reproduce

6. pathogens spread through cross-infection

7. more the antibiotic used = non-resistant bacteria die = # of resistant bacteria increases = gene spreads

8. excessive use of antibiotic = resistant bacteria

Nature of Science

NOS 1 Looking for patterns, trends and discrepancies- there are common features in the bone structure of vertebrate limbs despite their varied use.

5.3 Classification and Biodiversity

Understanding

• U1 The binomial system of names for species is universal among biologists and has been agreed and developed at a series of congresses.

• U2 When species are discovered they are given scientific names using the binomial system.

• U3 Taxonomists classify species using a hierarchy of taxa.

• U4 All organisms are classified into three domains.

• U5 The principal taxa for classifying eukaryotes are kingdom, phylum, class, order, family and genus and species.

• U6 In a natural classification, the genus and accompanying higher taxa consist of all the species that have evolved from one common ancestral species.

• U7 Taxonomists sometimes reclassify groups of species when new evidence shows that a previous taxon contains species that have evolved from different ancestral species.

• U8 Natural classification helps in identification of species and allows the prediction of characteristics shared by species within a group.

Application

A1 Classification of one plant and one animal species from domain to species level

A2 Recognition features of bryophyte, filicinophyta, coniferophyta, and angiospermophyta.

5.4