APES Chapter 9.1 Species Extinction

Summary

In Chapter Nine, the focus is on sustaining biodiversity and examining the impact of extinctions on humanity. The chapter delves into the honeybee population decline since 2006, known as colony collapse disorder, and its significance in pollination. It discusses the current extinction rate, which is a thousand to ten thousand times faster than the natural background rate, driven by human activities such as habitat loss and climate change. The video also covers the concepts of endangered and threatened species, highlighting the ecological 'smoke alarm' these statuses represent, and mentions several species at risk of extinction.

Takeaways

• 🐝 Chapter 9 focuses on sustaining biodiversity and the impact of extinctions, particularly using the honeybee population decline as a case study.
• 📉 Honeybee populations have been in sharp decline since 2006, a phenomenon known as Colony Collapse Disorder, affecting pollination of crops.
• 🌱 Commercial beekeepers truck hives to farms to support pollination, but have been experiencing losses of 30-40% of their stock annually.
• 🌐 Biodiversity is crucial as over-reliance on a single species can lead to significant problems, such as the current honeybee crisis.
• 🚨 Species are becoming extinct at an alarming rate, potentially a thousand to ten thousand times faster than the historical rate, largely due to human activities.
• 🌿 Habitat loss, climate change, and ocean acidification are highlighted as major causes of the increased extinction rates.
• 🌎 The current extinction rate is believed to be at least a thousand times higher than the natural background rate, with estimates suggesting over a hundred species going extinct each year.
• 🔍 Biodiversity hotspots like rainforests and coral reefs are at higher risk of extinctions due to their high biodiversity and ongoing degradation.
• 🏞️ Fragmentation of habitats, such as cutting through forests for development, can lead to isolation and problems for species movement.
• 🐯 The script discusses the difference between endangered and threatened species, with the former being at immediate risk of extinction and the latter having declining numbers but not yet critically endangered.
• 🌳 Species with specific niches, slow reproduction rates, or large territory requirements are more vulnerable to becoming endangered or extinct.

Q & A

What is the main focus of Chapter Nine in the context provided?

Chapter Nine focuses on sustaining biodiversity, examining the causes and impacts of extinctions, and exploring what can be done about it.

What is the 'colony collapse disorder' mentioned in the script?

Colony collapse disorder refers to the significant decline in honeybee populations and colonies since around 2006, which has been a cause for concern due to their crucial role in pollination.

How important are honeybees to pollination in the United States?

Honeybees pollinate approximately 71% of the vegetable and fruit crops in the United States, highlighting their vital role in agriculture.

What is the current trend in honeybee population according to the script?

The script indicates that there has been a decline in honeybee populations due to colony collapse disorder, with commercial beekeepers experiencing losses of 30 to 40 percent of their stock each season.

What are the potential causes of colony collapse disorder in honeybees?

The script suggests that potential causes could include factors such as certain fungi, pesticides, and other environmental stressors.

Why is it problematic to rely heavily on a single species for biodiversity?

Relying on a single species can create a significant problem if that species faces a crisis, as it can lead to a collapse of the ecosystem services it provides.

What is the current rate of species extinction as discussed in the script?

The script states that species are becoming extinct at least a thousand times faster than the historical rate, and it could be as much as ten thousand times faster.

What are some of the human-related causes of extinction discussed in the script?

Human-related causes of extinction mentioned in the script include habitat loss, climate change, and ocean acidification.

What is meant by the 'background rate' of extinction?

The 'background rate' of extinction refers to the natural, ongoing extinction rate that occurs due to normal environmental changes and is estimated to be about one species per million species per year.

What is the significance of the term 'mass extinction' as used in the script?

A 'mass extinction' refers to the extinction of many species over a relatively short geological period of time, which is currently believed to be influenced significantly by human activities.

What are 'biodiversity hot spots' and why are they important?

Biodiversity hot spots are areas with exceptionally high biodiversity, such as rainforests or coral reefs. They are important because they are areas where extinction rates are projected to be much higher than average, and they represent significant ecological value.

What does the script suggest about the future of extinction rates and ecosystem services?

The script suggests that the rate of extinction and threats to ecosystem services are likely to rise sharply in the next 50 to 100 years, which could impact the services that nature provides for human survival.