Evolution and Ancestry
Name the diagram that shows hypothesized relationships among species based on shared traits or DNA.
Phylogenetic tree (or phylogeny)
What biomolecule (DNA or protein) was used in the unit activities to build penguin trees?
DNA (the unit uses DNA data; earlier activities also referenced amino acids/proteins in one part).
Give one example of an isolation type (geographic, behavioral, or temporal) that can keep two penguin species reproductively separate.
Example answers: geographic isolation — separate breeding colonies on different islands; behavioral isolation — different mating calls or courtship displays; temporal isolation — breeding at different times of year.
What does the acronym HIPPO stand for in conservation threats? List the elements.
HIPPO: Habitat loss, Introduced species, Pollution, Population growth, Overconsumption. (Missing C = Climate change.)
What is an SSP in the context of zoo conservation?
SSP: Species Survival Plan — a cooperative program (typically run by AZA-accredited zoos) to manage breeding and conservation of endangered species to maintain healthy, genetically diverse captive populations and support recovery efforts.
Explain briefly why species that are geographically close often appear close together on a phylogenetic tree.
Species that are geographically close often exchange genes more recently or share similar selective pressures, so they tend to have more similar traits and DNA, placing them near each other on a phylogenetic tree.
Describe how comparing restriction fragment lengths can provide evidence of relatedness between species.
Restriction enzymes cut DNA at specific sequences; comparing the lengths of resulting fragments (restriction fragment length polymorphisms) between species shows where cuts differ. Similar fragment patterns indicate more similar DNA sequences, suggesting closer relatedness.
How could differences in beak shape lead to coexistence of multiple penguin species in the same area?
Different beak shapes are specialized for different prey types or feeding methods, reducing direct competition; e.g., one shape may be better at catching small fish while another is better at probing for crustaceans, allowing multiple species to use the same area but exploit different food resources.
Name two human activities from HIPPO that can directly reduce penguin carrying capacity in an ecosystem.
Examples: Habitat loss — coastal development destroying nesting sites; Pollution — oil spills or plastic ingestion reducing survival and reproductive success.
Why do studbooks and databases matter when making breeding recommendations across zoos? Give two reasons.
Reasons studbooks/databases matter:
Provide one piece of evidence (other than DNA) that scientists can use to infer common ancestry among penguin species.
Examples (any one acceptable): fossil record showing transitional forms; comparative anatomy (shared homologous structures, e.g., similar wing or flipper bones); similar embryological development; shared biogeographic patterns.
In a paternity activity, a chick's DNA shares bands A, B, and C with male 1, and bands A, B, and D with male 2. Which male is more likely the father and why?
Male 1 is more likely the father because the chick shares bands A, B, and C with male 1 (three matching bands) versus only two matches (A and B) or different banding with male 2; greater shared unique bands provide stronger evidence of paternity.
During the beak utensil lab, what would be a reasonable claim connecting utensil type to feeding success? State claim and one piece of supporting data you could collect.
Sample claim: “Utensil X produced higher prey-capture success than utensil Y.” Supporting data: number of prey items collected per trial by each utensil type (e.g., mean ± SD across trials) showing a higher mean for utensil X.
A conservation group must decide how to spend $250,000. List two criteria they should use to evaluate funding options (one ecological, one social/economic).
Why is it important not to select mates based on "favorite" animals?
Because selecting mates based on favorites can prioritize aesthetics or popularity over genetic considerations; that can increase inbreeding and reduce genetic diversity, undermining the long-term health of the managed population. Decisions should be based on genetic and demographic data.
What does it mean for a species to be "extant"? Use a complete sentence.
“Extant” means a species that is currently living (not extinct).
Define "mean kinship" in one sentence as used in captive breeding decisions.
Mean kinship is a measure of the average genetic relatedness of an individual to the rest of the population; individuals with lower mean kinship contribute more unique genetic material and are prioritized to maximize genetic diversity.
Many penguin species occupy different ecological niches. Describe two types of niche differences (not beak shape) that would allow sympatric penguin species to coexist.
Explain how climate change (the missing "C") could interact with another HIPPO factor to threaten penguins. Give a specific example.
Example: Climate change can warm ocean temperatures, shifting prey distributions; combined with overfishing (an HIPPO factor), penguins may face food shortages because their prey moves away or declines, reducing breeding success and survival.
Describe one method for monitoring population health over time using database records (what variable(s) you would track).
Method and variables to track: Use the database to graph population size over time and track birth rate, death rate, age structure, and mean kinship; monitoring trends (e.g., declining juvenile survival) can indicate health issues or management needs.
Interpret: If two penguin lineages diverged 5 million years ago, would you expect their DNA sequences to be more similar or less similar than lineages that diverged 500,000 years ago? Explain why.
You would expect the lineages that diverged 5 million years ago to have less similar DNA than those that diverged 500,000 years ago, because more time allows more mutations to accumulate, increasing genetic differences.
Explain how pedigree charts and mean kinship together help managers choose breeding pairs to maintain genetic diversity.
Pedigree charts show actual parent–offspring relationships and inheritance paths; mean kinship quantifies each individual’s genetic uniqueness relative to the population. Together they identify individuals whose pairing will minimize inbreeding and maximize retained genetic diversity.
Provide an explanation (claim, evidence, reasoning) for how behavioral isolation could evolve between two penguin populations that breed in the same colony.
Example CER:
Design idea: Briefly describe one management action a zoo SSP could prioritize to reduce extinction risk for Humboldt penguins, and one trade-off or limitation of that action.
Example management action and trade-off:
Given birth rate B and death rate D for a captive penguin population, write a basic expression for the population growth rate (births minus deaths). Then state one non-mathematical factor that could alter B or D in captivity.
Expression: Population growth rate ≈ B−DB−D (where BB = birth rate, DD = death rate; if using counts per time period, population change = births − deaths).