APES Chapter 9.1 Species Extinction
Summary
TLDRIn 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.
Outlines
🐝 Chapter Nine: Sustaining Biodiversity
Chapter Nine focuses on the importance of sustaining biodiversity, particularly through the lens of honeybee population decline, a phenomenon known as colony collapse disorder. Since 2006, honeybee colonies have been in sharp decline, affecting pollination services crucial for both vegetable and fruit crops. Commercial beekeepers often rent out colonies to farmers for pollination purposes. The chapter delves into the causes of this decline, which may include pesticides and other environmental factors. It emphasizes the dangers of relying too heavily on a single species for ecosystem services and encourages biodiversity as a more sustainable approach.
🌿 Mass Extinction and Human Impact
Paragraph two discusses the concept of mass extinction, highlighting that current extinction rates far exceed the natural background rate, potentially by thousands of times. It points to human-related causes such as habitat loss, climate change, and ocean acidification as significant factors. The paragraph also touches on the historical causes of mass extinctions, like asteroid impacts and volcanic activity, and contrasts these with the current human-driven factors. It emphasizes the rapid pace of habitat destruction and degradation, the role of human lifestyle and consumption, and the projected increase in extinction rates and threats to ecosystem services within the next 50 to 100 years.
📊 Estimating Extinction Rates and Species Status
This paragraph explores the challenges in estimating extinction rates due to the slow and gradual nature of natural extinction processes. It discusses how scientists observe habitat loss and its impact on extinction rates to make current estimates. The distinction between endangered and threatened species is clarified, with endangered species being at immediate risk of extinction and threatened species being at risk of becoming endangered. The paragraph serves as an ecological 'smoke alarm,' indicating that a decline in species numbers signals a problem within the ecosystem that requires attention.
🐾 Factors Leading to Endangerment and Extinction
Paragraph four examines various factors that contribute to species becoming endangered or extinct. It covers reproductive strategies, with K strategists like the blue whale and giant panda being particularly at risk due to their low reproductive rates. It also discusses the vulnerability of species with specialized niches, narrow distributions, high trophic levels, fixed migratory patterns, rarity, commercial value, and large territory requirements. The paragraph provides specific examples of endangered species, such as the Mexican gray wolf, California condor, whooping crane, and Sumatran tiger, emphasizing the urgency of conservation efforts to prevent their extinction.
Mindmap
Keywords
💡Biodiversity
💡Extinction
💡Honeybees
💡Colony Collapse Disorder (CCD)
💡Ecosystem Services
💡Habitat Loss
💡Climate Change
💡Endangered Species
💡Threatened Species
💡Mass Extinction
💡Biodiversity Hotspots
Highlights
Chapter nine is a companion to chapter four, focusing on extinctions and their impact on biodiversity.
Honeybee population decline since 2006, known as colony collapse disorder.
European honeybees pollinate about 71% of US vegetable and fruit crops.
Commercial beekeepers truck hives to farms to rent colonies for pollination.
30-40% decline in honeybee stock due to colony collapse disorder.
Dangers of relying too much on a single species for biodiversity.
Species extinction rates are currently a thousand to ten thousand times faster than the historical rate.
Human-related causes are accelerating extinction rates.
Natural background rate of extinction is about one species per million species per year.
Current estimates suggest we are in a mass extinction event.
Human population and resource consumption are major causes of habitat destruction.
Biodiversity hot spots like rainforests and coral reefs are at higher risk of extinction.
Coral reefs are degraded by pollution and ocean acidification.
Rainforests are being cut down for croplands, leading to habitat loss.
Estimates of extinction rates are challenging due to the slow nature of natural extinction.
Endangered species are at risk of imminent extinction, while threatened species are declining.
Regional extinction refers to species no longer found in areas they once inhabited.
Functionally extinct species have lost their interaction with other species.
Animals with low reproductive rates, specialized niches, or fixed migratory patterns are more vulnerable to extinction.
Commercially valuable species like rhinoceros are at risk due to poaching.
Large territorial requirements make species like the Florida panther vulnerable to extinction.
Several large animal species are critically endangered, such as the Mexican gray wolf and the California condor.
Transcripts
[Music]
foreign
hey guys welcome back here we are
for chapter nine
in chapter nine it is really sort of a
companion chapter
to chapter four i usually sort of teach
them together
so if you're looking at this chapter
truly independently
it's worth a look at least at the
extinction parts in
chapter four chapter nine sustaining
biodiversity what we're really going to
look at
are extinctions how do they affect us
and what can they do about it primarily
for this chapter we're going to kick
right off with the core case study
where have all the honeybees gone
as we know the honeybee population has
been declining since really about
2006 where they've even given it a name
the colony collapse disorder we have
seen the
european honeybee populations and
colonies
in really sharp decline now
this is obviously important because they
play such a key role
in pollination here in the united states
the european honeybees pollinate about
71
of the vegetable and fruit crops we tend
to think of them as
going by flowers but a lot of our
vegetables corn etc
actually have blooms which need
pollination now commercial bee keepers
actually
truck hives out to certain farms
a lot of farmers literally rent the bee
colonies
so a beekeeper brings the colonies out
to this
farmer's orange grove out to this corn
crop out to somebody growing cucumbers
you name it strawberries so they rent
this particular species of beef
and they bring out but we have been
seeing
about 30 to 40 percent of their stock
go down it's the colony collapse
disorder enough bees go and that entire
colony that's in one of the little bee
things collapses that is gone
they lose them they've been losing 30 40
of their stock every season
it's an issue it's a danger now we'll
look at it a little later but there's a
lot of reasons for it whether it's some
fungus whether it's
pesticides being used other things that
they're running into
but it is dangerous to rely this much
on a single species biodiversity tends
to wind up working
better for everybody when we rely too
much on one species
then it can create a huge problem
but honeybees one of these things that
we are
looking at and tracking and realize it's
an
issue now section 9.1
which we're hitting today is really
species
extinction once again a lot of overlap
from chapter four
so here we go species right now are
becoming extinct
at least a thousand times faster than
the historical rate
and it could be as much as ten thousand
times faster
than the historical rate once again
faster than this background
extinction and a lot of these are human
related causes which we're going to get
into in this chapter we're going to look
at habitat loss
climate change and ocean acidification
as some of these reasons
now extinctions are natural
but sometimes they increase
very sharply so it is a natural process
it's going on
all the time and we talk about the
background rate so the background rate
of extinction this is just what
is happening going on normal for
whatever reasons the normal habitat
changes in climate forest fires
volcano erupts disrupts an area just
happens
is about one species
per million species so for every million
species out there on the planet at any
given time
about one species go extinct a year now
we're unsure but we think there are
about 10 million
species on the planet so that'd be about
10 species
going extinct a year so if 10 species 10
12 15 8 that's just background
what we expect when the rate rises above
the background that's where we kind of
want to look around and go hey
what's happening what's going on
what we really believe we're in right
now is a mass extinction
event because we are well beyond
the background rate so a mass extinction
is extinction of many species in a short
period of time
now a short period of time can be
thousands
of years you know when we're looking at
fossil record and several hundred
million years ago and hey we don't find
any below this
it's not an overnight process it's still
hundreds if not thousands of years
but the past causes of mass extinction
events have where they're largely
unknown we feel pretty confident about
165 million years ago
was a large asteroid lots of data to
back that up
and evidence from it but many of the
others really are unknown it can be
multiple volcanoes can be other
asteroids comet
changes in the climate but something to
cause them
they've normally we believe been caused
by
large global changes in the
environmental
conditions you know once again where the
asteroid hit
rose up a dust cloud that blocks out a
lot of the sun so many
plants die off once again global change
cools off
sun doesn't get through disrupts the
food chain etc
but these mass extensions have always
been due to
environmental conditions if you will
now currently human population
are destroying and degrading habitats
at a rapid pace well once again think
about going and creating a farm
we cut down the trees to turn it into a
farm we cut down the grasslands to turn
it into a farm
we spray the pesticides to get the bugs
away so that our farms
yeah we're changing and degrading
the habitat so our huge resource
consumption
just our lifestyles in general in the
united states
have a large ecological footprint
we want lots of things these things have
to be made provided
harvested etcetera and because of that
our extinction rates have risen
sharply very recently once again
our best estimates are the current
extinction rate is some
thousand times higher than the natural
background rate
100 would be 10 species 200 percent
would be 20 species a year
300 30 you know we think we're at
more than a thousand times higher than
the natural back rate
at least 100 species a year and it could
be
a lot more this rate of extinction
and threats to our ecosystem services
are likely to rise very sharply in the
next 50 to 100 years
your lifespan remember ecosystem
services that are
those are all the things that nature is
providing for us
oxygen clean water basic
food that we need lively many of things
that we rely
on are happening in nature out in the
rural areas
most of us live in urban areas but we're
dependent on the ecosystem services from
the rural so this is what we are
worried about the mass extinction may
have an effect on
our ecosystem services the things we
need for survival
now there's a lot of biodiversity hot
spots
out there like the rain forest or a
coral reef
they just tend to have really high
biodiversity
and these are the places where
extinction rates are projected to be
much
higher than average we've seen our coral
reefs get degraded from
sometimes it's tourists going and being
in them so much
a lot of it's been pollution and
acidification
of the oceans because of the fossil
fuels we burn
creates higher levels of acid in the
ocean
we know with the rainforests we've been
cutting them down so that we have
croplands etc biologically diverse
environments
are being eliminated entirely or
highly fragmented remember fragmentation
is simply where we take a forest
and we cut a swath through it there's
still forests here and we have farmland
or housing
and we have another little forest here
used to be one big forest
well now it's fragmented and things
can't get from here to over there
and it can cause problems now
we're estimating that our extinction
rate is a thousand times above
background noise background extinction
rate
but there are problems with estimating
because natural extinction this
background
it's a long process once again it
doesn't happen
overnight unless we know there's this
one type of owl that only lives in this
type area we cut all the trees down
but as a general rule a species going
extinct is a long process you know the
numbers dwindle they get lower lower
eventually done or left so it's
difficult to document
our fossil record doesn't document
everything we don't have fossil record
of
every living thing but when we see like
these large
animals that we can recognize say like
the tiger
not around anymore those we can see
so a lot of times we kind of focus on
the ones that we can see and notice more
clearly
so we've only identified about two of
the seven
to ten million species on the planet
earth
and we know very little about the
ecological roles
of most of the identified species we
have
we've talked about some of these
keystone species
like the american alligator or the otter
and many of these species we don't
really realize the ecological niche that
they really
occupy and how important it is until
they're gone
obviously with honeybees we realize if
there were no more honeybees
our pollination rates would sharply
decrease so some things we know but
maybe
we don't so our approach is
to observe how reductions in a habitat
area affect extinction rates
and then estimate the current rates so
if we
know if we eliminate the things in this
area
what would happen then we look at how
much habitat we are
actually removing and we begin making
estimates because we know if we remove
this habitat
what would happen and then we look at
habitats that are being removed
and we have to begin to make some of our
estimates
there's problems with it it's not
perfect it might be a little high it
might be a little low
but we've gotten pretty good at these
estimates
now let's talk about endangered species
versus
threatened species now first off any
time that we see an endangered or
weak market endangered or threatened
this is an ecological
smoke alarm if this animal is going
extinct
why what's the problem there's a problem
with the ecosystem
otherwise they wouldn't be going extinct
so anytime we see the numbers of a
particular animal especially something
we can
see dwindling getting smaller and
smaller and smaller
it's a smoke alarm where there's smoke
there's fire
what's the problem so an endangered
species
we label it endangered if there are so
few
members of that species that they could
become
soon extinct and otherwise if we don't
do something
they probably will become extinct
a threatened species there are still
enough numbers
or individuals to survive
that their numbers are declining and if
the numbers keep declining
then we would move them into endangered
there are simply more
protections for an endangered animal
than a threat
but when an animal becomes threatened we
realize it could become endangered and
we really start trying to watch and pay
attention and do what we can
before it makes the endangered species
look so
just the difference between endangered
the biggest problem
threatened because after endangered
it's simply extinct we can get things
that are either
regionally extinct or functionally
extinct regionally extinct means
it is extinct in areas that it's
normally
found let's take something like the
tiger it once used to roam a
huge swath of lands
now it's restricted to very small areas
and a lot of times even preserves wild
elephants they used to roam most of
africa but now you only find them in
certain areas
so we could talk about them being
regionally extinct they used to be here
but they're not
the elk up in the appalachians have
become regionally extinct
elk aren't extinct but they are not
found in the appalachians anymore they
were hunted
out of existence now they have brought
in
from manitoba a new population of elk
which are thriving but once again they
were driven to extinction
regionally we can also talk about
something being
functionally extinct it's the point
where the interaction with other species
are lost have been greatly diminished
the white rhino it's functionally
extinct the last male is gone we have
two females but
it's time it's almost gone now that's
extreme
functionally extinct but when the
numbers get so small
they're not going to be able to make it
in the wild they're functionally
extinct we may still have them for a
very short period
but we'll see now
let's look at some of these animals and
why
where they are coming extinct so i'm
going to throw the picture up here
and we'll take a look at them there are
a lot of different reasons why certain
animals
come on this endangered or threatened
species list
there's certain reasons the first one up
there the blue whale
well this represents blue whale giant
panda rhinoceros they all
all have this same feature they
are uh k strategists once again their
reproductive style
is low reproductive rate
they give only birth to a few organisms
and they're very
long spaced apart they may not have a
you know they may have one calf and it's
two three years later before they have
another so since they have such a long
slow reproductive rate
if their numbers dwindle they're in
specific danger of extinction
the giant panda has such a specialized
niche when something has to survive only
on one type of food or one particular
area well if that thing becomes
threatened the animal becomes stretched
so things in a very specific
niche are more likely to become on a
threaded endangered species a narrow
distribution
uh like the elephant seal or the desert
pup
fish we only find them in this little
little teeny tiny area so that habitat
gets destroyed
or threatened they tend to get
the things that feed at really high
tropic levels it shows a picture of an
eagle could be eagle hawk these tertiary
consumers
something that's eating plants you're
pretty safe and then the thing
that's eating the thing that eats the
plants but the higher you go
up so i have a primary consumer
and herbivore i have a secondary
consumer
so we have the grasshopper eating the
grass i have the bird eating the
grasshopper but when i have a bird
eating the bird it's feeding at such a
high tropic level
that they become endangered things like
eagles tigers
bears or such like these it says it
shows a sea turtle
fixed migratory patterns where they
always migrate in the same way if the
climates change
the problem happens in the habitat they
become issues
some things are just very rare like the
african violet
now we can get them in homes and grow
them but in the wild
they're incredibly rare those are some
orchids as well the ghost orchid in
florida
very rare only happens in a little tiny
area in some swamps
if they are commercially valuable
rhinoceros rhinoceros largely went
extinct
because of cutting off its horn
rhinoceros horn was used in a lot of
homeopathic type things it was seen as
that being a
sign of strength and virulence to eat
rhino horn powder etcetera and then
also things that just require very large
territories
like our florida panther virtually it's
functionally extinct there's so few of
them because they require such large
territories as humans spread
and we cut out where they can live not
many of them around
anymore so these guys are
smoke alarms now this last one up here
we're just going to look at a handful of
large
animals if you will that have very
little left the mexican gray wolf
there's only about 114 of them left in
the arizona
mexico area the california condor
now we have about 300 of them in the
wild now
but back in 1986 there were only nine
left they were all captured
brought in they did breeding techniques
and they've been releasing them back
into the wild
through up to 300 but still very very
few
the whooping crane north america we
think it's only about 400 or so left
and also the cement sumatran tiger
there's a lot of different
tigers siberian title bengal tiger
sumatran
so off the island of sumatra in
indonesia
only about 400 of these left in the wild
a lot of these large animals we're going
to watch in our lifetime
if we're not very careful go extinct
that is it for section one
join me next time for section two when
we look at
why do we care take care guys we'll see
you next time
you
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