APES Video Notes 3.2 - K-selected & r-selected species

Summary

In this educational video, Mr. Speeds explores the contrasting reproductive strategies of K-selected and r-selected species. K-selected species, like elephants, invest heavily in fewer offspring, ensuring their survival through long lives and parental care. In contrast, r-selected species, exemplified by spiders, produce numerous offspring with minimal care, relying on quantity for survival. The video discusses the biotic potential, the spectrum of reproductive strategies, and how r-selected species are more likely to become invasive due to their rapid reproduction rates. It also touches on how K-selected species are more vulnerable to environmental disturbances and invasive competition, potentially leading to extinction.

Takeaways

• 🐘 K-selected species focus on quality over quantity, investing heavily in the care of fewer offspring, like elephants.
• 🕷️ r-selected species prioritize quantity, producing many offspring with minimal parental care, exemplified by spiders.
• 🌱 Biotic potential is higher in r-selected species, indicating a higher maximum reproduction rate compared to K-selected species.
• 🌈 Most species fall somewhere on a spectrum between purely r-selected and K-selected, such as frogs and hares.
• 🌿 r-selected species are more likely to become invasive due to their rapid population growth and competition for resources.
• 🐘 K-selected species are more stable near their carrying capacity but are slower to recover from environmental disturbances.
• 🌋 The slow reproduction and development of K-selected species make them vulnerable to disturbances like diseases or invasive species.
• 🌱 r-selected species' rapid reproduction can outcompete K-selected species for resources in new ecosystems.
• 🦠 The slower generation time and smaller population size of K-selected species reduce their adaptability to environmental changes.
• 📉 K-selected species are at a higher risk of extinction due to their inability to adapt quickly to new conditions.

Q & A

What are the two reproductive strategies discussed in the script?

The two reproductive strategies discussed are K-selected and r-selected strategies. K-selected species focus on quality over quantity, investing heavily in fewer offspring, while r-selected species produce many offspring with little to no parental care.

What is an example of a K-selected species mentioned in the script?

An example of a K-selected species mentioned is the elephant, which takes good care of its few offspring and lives a long time.

What is an example of an r-selected species mentioned in the script?

An example of an r-selected species mentioned is the spider, which produces hundreds of offspring and leaves them to fend for themselves.

What is biotic potential and how does it differ between K-selected and r-selected species?

Biotic potential is the maximum reproduction rate of a population. It is much higher for r-selected species than for K-selected species, as r-selected species produce many offspring.

Why are r-selected species more likely to become invasive?

r-selected species are more likely to become invasive because their populations grow rapidly, allowing them to outcompete other species for resources when they move to a new ecosystem.

How does the lifespan of K-selected species affect their reproductive strategy?

K-selected species, having a longer lifespan, can afford to spend more time and energy on parenting, leading to fewer but better cared-for offspring.

What is the relationship between the reproductive strategies and the vulnerability to environmental disturbances?

K-selected species, with their slow reproductive rate, are more vulnerable to environmental disturbances because their populations take longer to recover. r-selected species, with their rapid reproduction, can recover more quickly from such disturbances.

Why are K-selected species less likely to adapt to changing environments?

K-selected species are less likely to adapt to changing environments due to their longer generation times, smaller population sizes, and less genetic diversity.

What is the significance of the term 'carrying capacity' in the context of K-selected species?

The carrying capacity refers to the maximum population size that an environment can sustain. K-selected species usually exist near their carrying capacity because their populations grow slowly and are relatively stable.

How does the script illustrate the spectrum of reproductive strategies between K-selected and r-selected species?

The script shows a spectrum by mentioning species like the frog and the hare, which produce a fair number of offspring and show some parental care, falling between the extremes of K-selected and r-selected strategies.

What science skill is being practiced at the end of the lesson?

The science skill being practiced is describing patterns or trends in data, specifically analyzing the relationship between zebra mussel and unionin mussel population density in the Hudson River.