Bio 110 Unit 7 History Repeats Itself (2022/2023) 100% Pass

Bio 110 Unit 7 History Repeats Itself (2022/2023) 100% Pass What can observing what occured 56 million years ago do for us? It can help us understand what can happen today as a result of global warming. What do we reconstruct ancient temperatures through? Ice cores, tree rings, and a variety of other "proxies" and patterns that reflect the temperature. What's different with the temperature change we witness today? It is far greater than both the background temperature change and during the Paleocene- Eocene Thermal Maximum (PETM) What showed fewer plants with toothed leaves during the PETM? Data What occured given the warmer temperatures during that time? Plants with toothed leaves migrated to cooler temperatures near the Earth's poles. What has been discovered about the temperate adapted flora? That it is temporarily replaced by tropical flora before returning to the Bighorn Basin once the temperatures decreased. What happens in the current warming scenario? The rate of change is so dramatically high that the ecosystems may exceed their change thresholds and die before they can shift, leading to mass extinction What is insect herbivory? Fossil evidence of increased feeding on plant leaves. What does the fossil record show during the PETM? It shows a significant increase in insect consumption during the PETM What would we expect to see on a warming planet like we see today? Increased amounts of insect damage not just to native ecosystems but also to our crops. What were reefs built by in the past? Built by sponges, bryozoans, crinoids, and rugose corals (Paleozoic) and rudists (Mesozoic) What happened to these organisms? Some still exist in rare locations while others have gone extinct Why are coral reefs hugely important? Hugely important because of the roles they play in buffering the coast against storms and as nurseries for huge populations of fish that humans depend on for food. What consequences did we see through global warming? Forest systems migrated but did not suffer mass extinctions, Insect herbivory increased markedly, and coral reefs disappeared and did not return even after the world cooled. What other consequences were observed? Mammals shrank in size due to heat stress, ocean acidity increased, resulting in dissolution of animal and foraminera shells, more intense storms resulted in more erosion and loss of soil fertility, and rainfall became more variable and resulted in more frequent flooding and droughts. How much faster is the warming pattern today compared to the PETM? 100x times faster today than the PETM.