Unit 5

U: When does Evolution occur?

when heritable characteristics of species change

U: Outline what Fossil Records Show

evidence for evolution

• no modern organisms have fossils

  • organisms must change gradually

• fossil records appear in chronological order

  • older fossils have simpler organisms

U: Outline what does selective breeding shows

shows that artificial selection can cause evolution

• humans bred animals with favorable traits a.k.a. selective breeding

  • wild boars with more fat so we can eat yummy bacon

• change in traits was rapid

  • evolution was hyper-charged

U: Outline what homologous structures by adaptive radiation shows

similarities in origin, yet different structures and functions is best explained by evolution

the common ancestor gave the structure, the organisms changed the function

U: What happens to populations in a species?

can gradually diverge into separate species by evolution

U: What is an example of gradual divergence?

continuous variation across the geographical range of related populations

• populations in other places evolve separately and so over time, they become different species

A: Explain the 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

A: Compare 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)

U: What must occur for Natural Selection to initiate?

variation among members of the same species

What are Sources of Variation?

1. Mutation

2. Meiosis

3. Sexual Reproduction

U: Explain how Mutations are a Source of Variation

original source of variation

1. gene mutates

2. new alleles formed

3. enlarges gene pool

   1. more variation

U: Explain how Meiosis is a Source of Variation

1. diploid cells has certain combinations of alleles

2. meiosis occurs

3. crossing-over and change of bivalent orientation occurs

4. creates new alleles

U: Explain how Sexual Reproduction is a Source of Variation

1. gametes (sex cells) come from 2 different people

2. gametes fuse

3. alleles changed around

U: What are Adaptations?

characteristics that make an individual suited to its environment and way of life

U: What must be Stated about Populations and their Offspring?

the offspring are overproduced in relation to its environment’s resources

U: Explain Natural Selection

1. species produce more offspring than environment can support

2. there is a struggle for resources; some organisms die and others survive

3. In natural populations, there is variation between organisms

4. Some individuals are better adapted (A) than others

5. (A) individuals survive and reproduce worse adapted (B) die off

6. (A) individuals pass on their genes

7. frequency of (A) characteristics increases, while (B) decreases

8. species becomes better adapted

A: Explain 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

A: Explain Evolution of Antibiotic Resistance in Bacteria

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. excessive use of antibiotic = resistant bacteria

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

U: Outline the Binomial System of Nomenclature

• universal among biologists

• developed and agreed upon in a series of congresses

• used to give species scientific names

What are Taxonomists?

scientists who organize and name different living things

U: How do Taxonomists classify Species?

using a hierarchy of taxa

U: All organisms are classified into three ______. What are they? (just to be safe)

domains

1. Archaea

2. Eubacteria

3. Eukaryota

U: List the levels of principal taxa for classifying eukaryotes

1. Kingdom

2. Phylum

3. Class

4. Order

5. Family

6. Genus

7. Species

U: In a natural classification, the genus and accompanying higher taxa consist of…

all the species that have evolved from one common ancestral species

U: When do taxonomists have to change classifications?

when new evidence shows that a previous taxon contains species that have evolved from different ancestral species

U: What does Natural Classification help with?

identification of species and allows the prediction of characteristics shared by species within a group

What is the difference between Natural Classification and Artificial Classification?

• Artificial - categorizes based on specific criteria chosen by humans

• Natural - groups based on evolutionary relationships and shared characteristics

A: Classification of one plant and one animal species from domain to species level

Taxa	Blue Whale	Giant Redwood
Domain	Eukaryota	Eukaryota
Kingdom	Animalia	Plantae
Phylum	Chordata	Coniferophyta
Class	Mammalia	Pinopsida
Order	Cetecea	Pinales
Family		Mammalia
Genus
Species

A: