Untitled Flashcards Set

1. Briefly rewrite Darwin’s 5 observations (O) and 3 inferences (I) as they relate to Crows and Beetles. See the image below..  Observations 1-3 are done for you below.

O1: If all the beetles born each year survived to reproduce as adults, the population would increase exponentially.

O2: However, beetle populations remain stable in size.

O3: Beetle resources such as habitat and food are limited.  Crow resources such as food (beetles) are limited.

I1:

1. Your answers to these (and all) unit reading guide questions must be handwritten, typed answers will not be scored.

O4:  

O5:

I2:

I3: 

2. Explain “descent with modification”. (For example, review this video: https://www.youtube.com/watch?v=plVk4NVIUh8 

It means the evolutionary changes that have accumulated over time since two species split. Species change over time then give rise to a new species and share a common ancestor. 

3. Natural selection affects individuals or populations (circle one)?

Natural selection affects the population. 

4. What are structural homologies? (and, give an example)
   
   

5. What are molecular homologies? 

6. How does a theory differ from a hypothesis? 

7. Distinguish between artificial and natural selection:

Artificial selection- favorable traits are chosen in order to create a favorable phenotype. Selection is still acting on phenotype

Natural selection room- nature is not choosing the phenotypes that a organisms is born with that is decided by there genetic material. Natural selection is not random. The fittest survive and the one who is most adapted to the environment. 

(Gene Pools, Populations, Microevolution)

8. Write out the Hardy-Weinberg theorem and define each variable.

p+q=1

P=dominate trait allele frequency(allele 1)

Q=recessive trait allele frequency (allele 2)

P^2+2pq+q^2=1

P^2= homozygous dominant genotype

2pq= percentage of heterozygous individuals 

Q^2= recessive individuals 

The concept that if a population is at equilibrium it will exhibit one out of five traits. 

9. List the five conditions necessary for a population to remain at Hardy-Weinberg Equilibrium.

ALSO, write a few notes regarding how to remember each of the 5 conditions from “The Five Fingers of Evolution” video we watched in class. https://www.youtube.com/watch?v=5NdMnlt2keE 

1. No mutations

2. random mating (no reason to choose one mate over the other)

3. No gene flow

4. No gene drift

5. No natural selection 

If it meets these requirements it means the population is not evolving 

Five fingers of evolution drawn on paper

10. What is the Hardy Weinberg Equilibrium’s goal? (why would scientists use it?)

The Hardy Weinberg equilibrium's goal is to determine and compare alleles and their genotype frequencies in a population.  I believe that the hardy weinberg equilibrium helps tell scientists if a species is evolving or not and it can predict the allele frequencies which is important because it helps them see the deviations from the equilibrium and what might have caused it. It sees if the population is genetically changing. 

11. Define fitness and explain why relative fitness is zero for a healthy, long lived, sterile organism.

Fitness is an organism's ability to survive and reproduce. The ability to produce offspring is crucial for a population and allows there to be variation since the genes in each organism vary. The relative fitness is zero for a healthy long lived sterile organism because though it was able to survive it is not able to reproduce or pass on its genes to future generations. This organism had no contribution to the gene pool. 

12. Explain the role of population size in genetic drift:

Genetic drift is random and it is random changes to small populations. If it is a big population of organisms if there is a disruption it won’t be as big of a different which is why jt must be a small population. Smaller populations causes a bigger change.. Bottle neck- ex there is a bottle and beads in it and when you pour it out not all of them will come out and most will get caught in the bottle next so it causes a drastic change. A big disruption in a small population. It will decrease  the size of population randomly.

It will change frequency dramatically. Founder affect- random butterflies decide to fly away and take the gene pool with them and this affects the small population.

13. Distinguish between and give an example of: directional and disruptive selection. 

Directional selection is where one extreme is chosen so the graph will move towards that extreme.

Disruptive selection is where two or more extremes are chosen causing the graph to have multiple peaks. 

14. Explain heterozygote advantage (an example is malaria and sickle cell disease heterozygotes).

(Macroevolution &  Speciation)

15. Describe the difference between micro and macroevolution. Give an example of each.

Microevolution, or evolution on a small scale, is defined as a change in the frequency of gene variants, alleles, in a population over generations. Microevolution is a change in the frequency of gene variants, alleles, in a population, typically occurring over a relatively short time period.

The field of biology that studies allele frequencies in populations and how they change over time is called population genetics.

Microevolution is sometimes contrasted with macroevolution, evolution that involves large changes, such as formation of new groups or species, and happens over long time periods. However, most biologists view microevolution and macroevolution as the same process happening on different timescales. Microevolution adds up gradually, over long periods of time to produce macroevolutionary changes.

microevolution: populations, alleles, and allele frequency.

16. Use the table below: name the type of reproductive barrier and whether it is pre or postzygotic for the following examples (we did this in class)

17. How do the reproductive barriers of temporal and behavioral isolation differ?

18. How do the reproductive barriers of gametic and mechanical isolation differ?

19. Compare and contrast allopatric and sympatric speciation.

20. Define adaptive radiation and describe the circumstances under which it may occur. Give an example.

21. Describe how punctuated equilibrium and gradualism are examples of two different tempos (time frames) of speciation.

22. How could homeotic genes be involved in macroevolution?

 (The History of Life on Earth)

23. What were the conditions on early Earth that made the origin of life possible?

24. The fossil record can provide structures for us to compare and date throughout various layers. How are scientists able to identify mammals and trace back the origin of mammals using fossils?

25. (These are not on the test, but do them anyway) When did prokaryotes arise?  

Prokaryotes arose around 3.5 to 3.8 billion years ago

When did oxygen begin increasing in our atmosphere? 

Oxygen began to increase significantly in earth's atmosphere around 2.4 to 2.1 billion years ago

When did plants appear?

Plants appeared around 470 million years ago

When did humans appear?
humans appeared more then 300,000 years ago

26. What is the theory of plate tectonics?
    And why is it a theory?
    
    

27. How do plate tectonics and continental drift affect extinctions?
    
    

28. What is meant by the phrase “evolution is not goal oriented”, give an example.

(Classification & Phylogeny)

29. What is phylogeny?

30. Give an example of a homologous trait:

A homologous trait is a trait that organisms share from a common ancestor, So it is a variation in the structure that was present in a common ancestor. An example of this is the bone structure of arms in humans, cats, and horses. They share that similar structure but it has been lightly modified so it is not identical. 

Give an example of an analogous trait:

 An analogous structure is when organisms share traits and characteristics but that comes from similar environments and habitats and not from a common ancestor. An example of this would be wings of a bat and wings of a bird. 

31. Explain why bird and bat wings are homologous as vertebrate forelimbs and analogous as wings.

32. The classification name of Drosophila melanogaster is what level of classification (Google it if necessary)?

33. What is parsimony?

34. Use the diagram below to answer these questions:

    1. List all of the animals that have jaws

2. List all of the animals that have fur and mammary glands

3. List all of the animals that DO NOT have lungs

4. List all of the traits that a lizard has

5. Why are feathers on the pigeon’s branch of the phylogenetic tree and not the main branch between claws and fur? explain.

35. Use the diagrams below to answer these questions.
    a.  Why is the lancelet labeled as the outgroup?
    B. the bass is more closely related to the frog or the leopard?
    C.  Which animals all have 4 walking legs?
    D. Which animals DO NOT have a vertebral column?
    
    
    

• a. The lancelet is labeled as the outgroup because it represents a more primitive lineage that diverged earlier in the evolutionary history compared to the other organisms in the diagrams.

• b. The bass is more closely related to the leopard than to the frog, as both the bass and leopard belong to the same superclass of vertebrates, while the frog is in a different class.

• c. The animals that all have 4 walking legs include the bass, frog, and leopard, as they are all tetrapods.

• d. The animals that do NOT have a vertebral column are the lancelet and the bass, as the lancelet is a protochordate and does not possess a backbone. e. The classification of these animals illustrates the evolutionary relationships among different species, highlighting how traits such as the presence of limbs or a backbone can define their categorization.