Page 11 - \2023-bfw-APES-TE-4e.indd

Use the margin content to prepare engaging lessons, with tips and
activities for every major concept in the course.
Copyright 2023 BFW Publishers. Pages Not Final. For Review Purposes Only. Do Not Share.
The margin content helps
you to:
each of the
PRACTICE each of the
seven science practices
from the course and exam
description to prepare for
exam day.
TEACH concepts and clarify
concepts and clar
ify
misconceptions through
engaging discussion starters
and more.
students with
ENGAGE students with
group activities, labs, and
opportunities to interact with
the environment outside the
classroom.
CONNECT concepts
concepts
throughout the course to
spiral major ideas and help
students see how concepts
build on one another, on
other disciplines, and relate to
other regions.
ASSESS student under-student under- Activity
standing with answers to the
questions that students will see
throughout the book.
In addition:
at the beg
inning
Bell Ringer at the beginning
of each module help you draw
students in right from the start of
class by accessing prior knowledge.
Find an activity or discussion
®
guide for every AP Exam
Tip in the book with
Tip in the book with
Teaching the AP Tip .
®
TE-xiv Features of the Teacher’s Edition
01_friedlandrelyeaTE4e_47542_FM_i_liii.indd
resulted in an almost complete halt to photosyn-
4,000 thesis, and thus an almost total lack of food at the
bottom of the food chain. Among the few species
that survived was a small squirrel-sized primate that
Number of genera 3,000 was the ancestor of humans.
PRACTICE 2,000 The Sixth Mass Extinction
Data Analysis (SP5) 1,000 As is evidenced by what we know about the five
global mass extinctions, environmental scientists
(5 minutes) Help students concep- 0 can learn about the effects of large and small envi-
ronmental changes by studying historic events.
300
200
tualize the time scale on the x axis of 500 400 Time (millions of years ago) 100 0 They can then apply the lessons learned from these
Figure 11.6. While it may appear that
past events to help predict the effects of the envi-
mass extinctions happened quickly FIGURE 11.6 Mass extinctions. Five global mass extinction events have ronmental changes that are taking place on Earth
today. During the last two decades, scientists have
occurred since the evolution of complex life roughly 500 million years ago.
because of the steep drop in number of
reached a consensus that we are currently expe-
(Data from GreenSpirit, https://www.nationalgeographic.org/media/mass-extinctions)
genera, note that the scale covers over riencing a sixth global mass extinction of a mag-
nitude within the range of the previous five mass
500 million years! Therefore the “rapid”
die off might actually have occurred interactions further restricting where a species can live as its extinctions. Given that we have poor data on the abundance
of most species, especially the very small invertebrate ani-
over several million years. Point out to realized niche. mals, estimates of extinction rates vary widely. These esti-
mates are extrapolated from extinction rates observed in a
students that each major hash mark
on the x axis is 100 million years. Now The Five Global Mass Extinctions few well-described groups of organisms. For example, the
Millennium Ecosystem Assessment, which is conducted by
ask them to estimate how long a mass
the United Nations, has estimated the extinction rate at 24
extinction event lasted. While mass Throughout Earth’s history, individual species have evolved species per day. In contrast, the United Nations Convention
and gone extinct. The fossil record has revealed five periods
on Biological Diversity has estimated the extinction rate at
extinction events appear abrupt, with a of global mass extinction, in which large numbers of spe- 150 species per day. What we know for sure is that there
cies went extinct over relatively short periods of time. The
large number of species lost in a very
have been about 800 confirmed extinctions during the past
short time period, students should note times of these mass extinctions are shown in FIGURE 11.6. 400 years, which represents a rate of about 2 species per
Note that because species are not always easy to discrim-
year. These confirmed extinctions do not include any pos-
that the extinction event may have taken inate in the fossil record, scientists count the number of sible extinctions of species not yet discovered, making it is
genera, rather than species, that once roamed Earth but are
hundreds of thousands of years.
difficult to know the true extinction rate.
now extinct. As we will see, several of these mass extinction
There is widespread agreement among scientists that the
events are associated with major changes in the environ- current mass extinction has human causes. These causes
ment around the planet that made it difficult for species to
include a wide variety of environmental changes that are
TEACH
Teaching Tip survive outside of their ecological tolerances. pushing species outside of their ecological tolerances, such as
The greatest mass extinction on record took place
habitat destruction, overharvesting, introductions of invasive
(5 minutes) Emphasize to students that 251 million years ago when roughly 90 percent of marine species, climate change, and emerging diseases. We’ll use our
species and 70 percent of land vertebrates went extinct. The
new understanding of the importance of ecological toler-
cause of this mass extinction is not known. A better-known
ances when we examine all of these factors in detail in Unit 9.
environmental changes can be natural mass extinction occurred at the end of the Cretaceous Because much of the current environmental change caused by
or anthropogenic. Natural environmental
period (65 million years ago), when roughly one-half of
human activities is both dramatic and sudden, many species
cycles, such as change in global tem- Earth’s species, including the dinosaurs, went extinct. The may not be able to move or adapt in time to avoid extinction.
cause of this mass extinction has been the subject of great
perature, tend to occur over long periods debate, but there is now a general agreement that a large In this module, we have explored the idea that individuals
meteorite struck Earth and produced a dust cloud that cir-
of time that give some organisms time
and species have specific environmental conditions under
to adapt or new species to fill niches left cled the planet and blocked incoming solar radiation. This which they perform well. Thus, the concept of ecological
tolerance is not only useful for understanding why differ-
by extinction. The time scale of human
ent species are found living in different biomes around the
induced environmental change is much Mass extinction A large number of species that went extinct world, but also how human-caused environmental changes
have the potential to reduce the abundance of many species,
more rapid.
over a relatively short period of time. with some being driven to extinction.
126 UNIT 2 ■ The Living World: Biodiversity
03_FriedlandRelyea4e_40928_Unit 2_094_171.indd 126
ENGAGE ENGAGE where the organism lives, what it eats or the 25/01/23 4:15 PM
Activity nutrients it needs, and an explanation of why it is
on the endangered species list. The poster should
(5 minutes) Ask students to turn to a (60 minutes) After teaching about the sixth list at least five actions that could help protect
the organism. Depending on the organism, the
partner and discuss the following: What mass extinction, ask students to create a “Most preservation list might include refusing to buy
distinguishes the sixth mass extinction
Wanted” poster. Assign each student an organ-
from the previous five events? (The ism from the International Union for Conservation it in the pet trade, working to conserve habitat,
breeding programs, or planting.
of Nature (IUCN) endangered species list. Unit 2
sixth mass extinction is being caused by
human activity including habitat destruc- Web Resources contains a link to the IUCN web-
tion, overharvesting, climate change, site. Students should create a poster describing TRM Unit 2 Web Resources
introduction of invasive species, and the animal, including a picture, information on
emergent diseases.)
emergent diseases.)
126 Unit 2 The Living World: Biodiversity
126
14 27/01/23 1:09 PM