APES Notes 2.1 - Introduction to Biodiversity

Summary

In this educational video, Mr. Smeeds introduces biodiversity, highlighting its three levels: ecosystem, species, and genetic diversity. He emphasizes the importance of each level in maintaining healthy ecosystems and discusses how species richness and evenness contribute to ecological balance. The video illustrates the benefits of genetic diversity for population resilience against environmental stressors and explains the detrimental effects of bottleneck events and inbreeding. Finally, it underscores that higher biodiversity fosters ecosystem resilience, enabling recovery from disturbances like wildfires or hurricanes. Viewers are encouraged to engage with the material through further discussion and practice.

Takeaways

• 🌱 Biodiversity refers to the variety of life in a given ecosystem and can be measured on three levels: ecosystem diversity, species diversity, and genetic diversity.
• 🏞️ Ecosystem diversity encompasses the number of different habitats available in an area, supporting a wide range of plant and animal species.
• 🌳 Species diversity is measured by species richness (the number of different species) and species evenness (how evenly individuals are distributed across species).
• 📊 Higher species richness is generally an indicator of a healthier ecosystem, as it signifies a greater availability of resources.
• ⚖️ Species evenness is crucial for understanding the balance of populations in an ecosystem; a balanced community is more resilient.
• 🧬 Genetic diversity refers to the variation in genes among individuals in a population, enabling better adaptation to environmental changes.
• 🌾 Populations with high genetic diversity are more resilient to environmental stressors, such as diseases or climate changes.
• 🔥 Bottleneck events can drastically reduce genetic diversity by eliminating many individuals regardless of their genome, leading to a vulnerable population.
• 🐆 Inbreeding can occur in small populations, increasing the likelihood of harmful mutations and decreasing overall fitness.
• 💪 Promoting biodiversity at all levels enhances ecosystem resilience, allowing ecosystems to recover more effectively from disturbances.

Q & A

What is biodiversity and how is it measured?

Biodiversity refers to the diversity of life in a given ecosystem and can be measured on three different levels: ecosystem diversity, species diversity, and genetic diversity.

What constitutes ecosystem diversity?

Ecosystem diversity is the number of different habitats available in a given area, which can include various ecosystems such as oceans, rivers, grasslands, forests, and deserts.

How is species diversity assessed?

Species diversity is assessed through two main measures: species richness, which is the total number of different species in an area, and species evenness, which reflects how individuals are distributed among those species.

What is species richness and why is it important?

Species richness (denoted as 'r') refers to the total number of different species found in an ecosystem. Higher species richness usually indicates a healthier ecosystem as it reflects the quality of resources like clean water and nutrient-rich soil.

What role does species evenness play in ecosystem health?

Species evenness indicates how evenly individuals are distributed among different species in an ecosystem. A balanced distribution suggests a more stable ecosystem, whereas dominance by a few species can indicate ecological imbalance.

What is genetic diversity and its significance?

Genetic diversity refers to the variety of genes within a population. Higher genetic diversity enhances a population's ability to adapt to environmental stressors, such as diseases or changes in habitat.

What is a bottleneck event, and how does it affect genetic diversity?

A bottleneck event occurs when a significant portion of a population is abruptly eliminated due to environmental disturbances. This event reduces genetic diversity and can make the remaining population more vulnerable to future threats.

How does inbreeding impact populations?

Inbreeding occurs when closely related individuals mate, which increases the likelihood of harmful mutations and can lead to decreased fitness in offspring, making populations more susceptible to decline.

Can you provide an example of inbreeding depression?

The Florida panther experienced inbreeding depression due to a drastic reduction in population size, resulting in harmful mutations. Conservation efforts included introducing pumas from Texas to increase genetic diversity and improve the population's health.

What is ecosystem resilience and its connection to biodiversity?

Ecosystem resilience is the ability of an ecosystem to recover from disturbances. Higher biodiversity contributes to resilience by ensuring a diverse array of plants and animals can support quick recovery and stability after environmental changes.