Student Worksheet

Question 1. Watch the video to answer the following questions.

1. What type of evidence did scientists use to determine the common ancestor of all bird of paradise species was a crow-like bird?

2. What is the definition of a species?

3. What was the first step for the bird species in the video to be on their way to becoming a new species?

4. After how many generations were the mainland and island birds in the video different species?

5. If one generation (the time between an organism being born and reproducing) for the birds in the video is 3 years, calculate how many years it took the island birds to become a separate species from the mainland birds.

6. What were the two scenarios for speciation that occurred in the video?

7. What three elements are required for speciation to occur?

8. Explain how there is now a huge diversity in bird of paradise species, evolved from a common crow-like ancestor.

Question 2. Select one plant or animal from the list provided. You will need to research your chosen organism to understand its adaptations and possible variations in traits in order to answer the following questions.

Purple Swamphen (Porphyrio porphyrio) (https://australian.museum/learn/animals/birds/purple-swamphen/)

Weka (Gallirallus australis) (http://nzbirdsonline.org.nz/species/weka)

New Caledonian Giant Gecko (Rhacodactylus leachianus) (https://www.reptilepark.com.au/new-caledonian-giant-gecko/)

Nikau Palm (Rhopalostylis sapida) (https://www.palmpedia.net/wiki/Rhopalostylis_sapida)

Tasmanian pepperberry (Tasmannia lanceolata) (https://www.australianplants.com/plants.aspx?id=1437)

Spur-legged phasmid (Didymuria violescens) (https://en.wikipedia.org/wiki/Didymuria_violescens)

a. Describe an environment the organism lives in (use the prompts in the table as a guide):

b. Adaptations are features that help an organism survive its environment. List 4 adaptations that help this organism survive in its natural environment.

For example: The shape of a bird's beak is different depending on what kind of food it eats.

c. Choose 5 trait variations that exist in your population.

For example: Plants may have differences in colour, size, shape, growing speed, light requirements.
Animals may have differences in colour, size, movement speed, eyesight, claw/teeth/beak length.

In every population, there are variations in traits. Some traits may be more useful in the environment than other traits.

Remember: Variation is necessary for speciation, as each population favours different traits over time until they eventually become a unique factor.

Question 3. Imagine the population of your organism are blown/swim/hitch a ride on vegetation, moving from the environment you researched in Question 2 to a new island environment on Lord Howe Island.

Remember! Isolation from the original population is necessary for speciation, as the two populations will no longer breed.

a. Read the environment information at your station and list the environmental factors of this new environment that will exert selection pressures on the population of your organism.

Hint: What food sources are there? What factors might lead to more predation? (are there places to hide?) What abiotic factors, such as heat or rainfall, might affect the organism?

Remember! Selection pressures are factors that will determine which variations in traits will help your organism survive. Selection is necessary for speciation as it will determine which traits are passed on and will be magnified over many generations.

b. Look back over your list of trait variations in your population (Question 2c). Which of these down which variations will be most advantageous in this new environment and thus are more likely to survive and reproduce? Indicate these in some way by circling, marking, or highlighting them.

c. Imagine the population of your organism reproduces for 100 generations without any mutations (no new genes enter the gene pool). Individuals without advantageous trait variations did not survive to reproduce so the population is now representing traits that help the organism survive in the environment.

Describe the phenotypic traits (observable characteristics) and draw an individual from this new population.

d. Mutations introduce new genes into the gene pool. For example, a mutation may generate bitter tasting leaves or provide an increase in speed or strength.

Assume there have been 2 mutations in the gene pool that have increased the population’s ability to survive and reproduce. (Remember: Not all mutations are beneficial, but for this activity, choose two that would be.)

List those two mutations and why each will be advantageous.

Hint: The mutations could help the individual with biotic factors (eg. defend against predators, hide, find food) or withstand abiotic factors.

e. Your population has now reproduced for 10,000+ generations and there have been many small mutations that have occurred. Some were not advantageous and did not get passed to the next generations, but your individual is now representing all of the advantageous mutations that occurred in the past 10,000 generations. Reminder: Mutations are small changes in genetic code and thus the new traits have to be plausible.

Draw an individual from your new population.

Question 4. Compare your organism to its ancestor and answer the following questions.

a. What evidence would scientists look for to determine if your individual has undergone speciation?

b. For speciation to occur, your new individual must be genetically different to the species of your original population. Do you think your individual has become a new species?

Reflection

Write a short paragraph explaining to a friend how speciation occurs. It must include the words: variation, isolation, selection.

Lord Howe Island - Simulated Speciation

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