Sign In | Subscribe
Start learning today, and be successful in your academic & professional career. Start Today!
Loading video...
This is a quick preview of the lesson. For full access, please Log In or Sign up.
For more information, please see full course syllabus of Biology
  • Discussion

  • Download Lecture Slides

  • Table of Contents

  • Transcription

  • Related Books

Bookmark and Share

Start Learning Now

Our free lessons will get you started (Adobe Flash® required).
Get immediate access to our entire library.

Sign up for Educator.com

Membership Overview

  • Unlimited access to our entire library of courses.
  • Search and jump to exactly what you want to learn.
  • *Ask questions and get answers from the community and our teachers!
  • Practice questions with step-by-step solutions.
  • Download lesson files for programming and software training practice.
  • Track your course viewing progress.
  • Download lecture slides for taking notes.
  • Learn at your own pace... anytime, anywhere!

Ecology, Part II

Lecture Slides are screen-captured images of important points in the lecture. Students can download and print out these lecture slide images to do practice problems as well as take notes while watching the lecture.

  • Intro 0:00
  • Mimicry 0:05
    • Batesian Mimicry
    • Müllerian Mimicry
  • Camouflage 3:23
    • Blend In with Surroundings
    • Evade Detection by Predators
  • Succession 5:22
    • Primary Succession
    • Secondary Succession
  • Biomes 9:31
    • Terrestrial
    • Aquatic / Marine
  • Desert 11:20
    • Annual Rainfall
    • Flora
    • Fauna
  • Tundra 14:49
    • Annual Rainfall
    • Permafrost
    • Flora
    • Fauna
  • Taiga (Boreal Forest) 16:59
    • Annual Rainfall
    • Largest Terrestrial Biome
    • Flora
    • Fauna
  • Temperate Grassland 19:07
    • Annual Rainfall
    • Flora
    • Fauna
  • Tropical Grassland (Savanna) 20:41
    • Annual Rainfall
    • Flora
    • Fauna
  • Temperate Deciduous Forest 22:19
    • Annual Rainfall
    • Flora
    • Fauna
  • Tropical Rain Forest 24:11
    • Annual Rainfall
    • Flora
    • Fauna
  • Lakes 28:05
    • Eutrophic
    • Oligotrophic
    • Zones
  • Estuaries 32:56
    • Area Where Freshwater and Salt Water Meet
    • Mangrove Swamps
    • Nutrient Traps
    • Organisms
  • Marine 34:50
    • Euphotic Zone
    • Pelagic Zone
    • Abyssal Plain
  • Conservation Summary 40:03
    • Biodiversity
    • Habitat Loss
    • Pollution
  • Climate Change 47:03
    • Global Warming
    • Greenhouse Gases
    • Polar Ice Caps
    • Weather Patterns

Transcription: Ecology, Part II

Hi, welcome back to www.educator.com, this is the lesson on ecology, part 2.0000

Another interesting thing you see in ecology is how organisms are able to mimic or look like something else.0007

It is thanks to evolution over time, thanks to particular mutations that worked out for them 0014

and are able to pass on to their offspring.0021

If you can look like something that is dangerous but you are not actually dangerous, that is a plus.0023

You are probably not going to be eaten as much.0029

Some animals have developed mutations over millions of years, that allow them to look like other harmful animals.0031

Like Batesian mimicry, this is when a harmless species looks like another species that actually is harmful or toxic.0036

Named after a scientist with the name of Bates.0046

Batesian mimicry, a great example is with the hawk moth larva.0049

These larvae are going to become the hawk moth, when they go to their metamorphosis.0054

They look kind of like a little snake, if you look carefully, it looks like it has little eyes.0061

There are other pictures where depending on the angle they take the photograph, 0067

it is remarkable how much it looks like a snake head.0071

There will be birds that normally would eat this larvae, they love to eat these caterpillars,0074

but they think it is a snake, they stay away from it.0080

Way back when, who knows when, one of these larvae was born with this mutation.0084

Since it did not get eaten, it got passed on.0090

Now, it is something that you see throughout the species.0095

It is spread to the point where the hawk moth larvae look pretty intimidating.0097

That is Batesian mimicry, when one that is harmless looks like one that is harmful.0103

That is a success story for the harmless one.0108

Then you have Mullerian mimicry, which is when both species are harmful and they look like each other.0113

They might have different levels of toxicity or how harmful they are, but it turns out that they developed a similar look.0122

I want to just emphasize this that, if you look in most textbooks and a lot of websites, 0131

the viceroy butterfly and the monarch butterfly usually you are going to see them described as Batesian.0137

For years, I taught it as Batesian because the thought was that, the viceroy was not toxic0143

meaning it is palatable and the monarch is toxic.0151

You will say that the viceroy, since it looks like the monarch,0156

the animals that have learned to not eat the monarch butterfly, they avoided the viceroy.0160

Research has shown in recent years, that the viceroy actually has a level of toxicity.0166

It is toxic, that actually it is better to call it Mullerian mimicry.0175

They do have slightly different patterns, if you look carefully, you can see that the monarch has this going on,0182

this little black line here that you do not see here.0189

There is a slight difference in the oranges, but nonetheless, 0192

they look very same to each other and they both happen to be harmful.0196

That is Mullerian mimicry.0201

Related to mimicry is camouflage.0205

A mimic is where one organism appears like another living organism.0208

Camouflage is where the animal can blend into its background, to whatever its habitat is.0212

Many species have gradually evolved the ability to blend in with their surroundings.0219

This helps them evade detection by predators.0224

This particular bug here, you can see it looks almost like dead leaves.0227

There are other pictures where it would blend way more to its environment.0233

But if it is staying still, a lot of animals that do not see the same colors that you and I do,0237

would mistake this for being plant material.0243

If you are looking for an insect to eat, they are not going to see it.0246

The stick bug, amazingly, when it stays still, can blend into a tree quite easily.0249

You have to look carefully for this one, this is a fish, it is a flounder that is blending into these little pebbles.0258

Its coloration on the scales has maximized the ability for it to blend into the environment.0265

Not only are predators are not going to be able to see it as much but whatever this eats, 0274

they may not see the flounder either.0280

This is the most amazing that I have seen, there is actually a reptile here, a kind of gecko that is blending into this log.0282

It is really tough to see, there is the head and here is the body.0291

You have to look carefully but it is grasping onto this log.0303

There is its eyes and that is a gecko, it is really tough to see but an amazing case of camouflage,0310

where this has a coloration pattern that looks so much like a log.0317

Succession is about, if you have an environment with no plants, 0323

what are the steps you get to having like a full-on forest, a full-on dense population of plants or dense community of plants?0329

There are two types, primary succession is primary because it is the first time that you have had plants colonizing it.0339

Primary succession, you have to start out with this right here.0349

Number one is bare rock. Usually, if this were to occur today, it would be lava rock.0353

If you have volcanic activity in the ocean, you have enough lava that ends up coming through to the surface.0365

You can have a small island developing.0373

Once that lava cools, it is new earth, in a sense.0375

Yes, it starts out very hard and it starts out to the point where you cannot have roots digging into because it is so dense and so hard.0380

Over time, you can get tiny little plant life settling in there.0389

You are probably going to start out with stuff like algae, lichens, things that do not have deeper roots0394

and do not depend on rooting themselves to get that height.0401

You will start out there and you will have that for years.0404

You will have those very tiny little plants.0407

Eventually, you will get to the point where you have some very tiny little grasses growing after that point.0411

It has to do with that lava rock or the hard rock getting to the point0419

where it is broken down a bit to get more like soil that we are used to seeing.0424

Eventually, grasses can lead do having these low level bushes.0428

Eventually, these little bushes is going to become larger shrubs.0433

Shrubs one day can lead to tress getting in there.0437

Over time, more and more trees, they get larger and larger.0441

It is this gradual succession, accumulation of plant life to the point where the soils are getting softer and softer, 0446

and able to be colonized by these larger plants.0455

It is how you get from bare rock to a forest.0459

The other kind is secondary succession.0464

It is when you have a natural disaster of some kind that has decimated the plant life.0467

There are already lots of plant species there, a fire, something of that nature,0476

unintended something of that nature, is destroying everything.0483

Here we have a lovely forest in picture 1, the sun is shining, life is good.0486

And then there is a spark, it could be lightning, it can be manmade.0494

The fire destroys everything, no more plant life.0500

Since, you already had an established soil there, the times it takes to get to level 8 compared to primary succession is way less0508

because you do not have to break down that rock over time and soften the soil to get those larger plants. 0517

The amount of time it takes to get from these little grasses and shrubs and tiny trees, up to point where we have big trees is less.0523

Something else to keep in mind is once you get to level 8, this last level, whichever succession it is, 0532

you are probably going to have less amount, in terms of the numbers of these low level plants.0538

You can see that actually in this illustration, they get crowded out.0546

The more large trees you have with big canopies, the more that sunlight will get blocked out from these little plants down below.0551

That tends to be the trend with forests that have been around for a long time.0560

You do not have as many grasses and shrubs at the lower levels.0566

Now onto biomes, biomes are these different types of ecosystems on earth.0572

They vary according to temperature, altitude, rainfall, and the flora and fauna.0578

By the way, flora is the plant life and fauna is the animals.0584

I’m going to use these terms flora and fauna for the rest of this lesson.0600

You are going to have terrestrial biomes, the different types of ecosystems on land.0606

Also in the water, you are going to have different kinds of life in lakes and in the oceans.0611

These water based ecosystems, they have quite a variety too.0620

If you look at this map, you got a pretty cool illustration of the major kinds of terrestrial biomes.0624

It is tough to read some of these but some examples.0629

Tundra, it is up at the top here, very high latitude, it is very cold.0633

The other extreme would be, when you look at the rain forest or tropical rain forest is this dark green.0640

You tend to see that along the equator.0646

In between, lots of differences, it has to do with the latitude, it has to do with how high it is.0650

For instance, look what you see here, you have the Himalayan mountains here, huge mountain range, very high up because it is so high up, it is very cold.0659

The atmosphere pressure is different, it does not support a lot of life in this mountain range.0668

Altitude has an impact in addition to the latitude, the rainfall, and the temperature.0674

The first terrestrial biome we will talk about is the desert.0681

Annual rainfall, pretty low, lowest rainfall of the major terrestrial biomes, less than 25 cm of rain annually.0684

It certainly depends on the desert, there are parts of the Sahara that get hardly anything.0694

These are color coded here according to how intense the desert is.0701

You do have pockets where it is just incredibly dry and really no life is being supported.0707

There are areas like in the American Southwest where there is quite a bit of life in the deserts 0715

because the temperature is extreme, is not always so bad.0720

It does get incredibly hot but there is enough rainfall to support the life.0726

The temperature range speaking of extremes is 7° C tolerable up to 40° C, or maybe 100 ℉, extremely hot.0731

The desert you will usually find around 30° latitude north or south.0745

Equator is right around here and that is 0° latitude.0752

30° is right about here, look at what we got, we got a lot of desert surrounding that area.0764

Down here at about 30°, look at what we got.0772

That is an interesting trend when you look at the latitude lines, north and south,0780

how you tend to get deserts in those areas.0785

One of the reasons why deserts have such a low amount of water annually is not just the lack of rainfall,0787

it is also the lack of the cloud cover in terms of like keeping it cooler.0795

A lot of times there is hardly any clouds at all, it heats up the area quite a bit.0801

The dry winds are blowing away a lot of the moisture that settles in other biomes.0807

When we look at the different kinds of plants, it is not the case where like deserts are lifeless.0815

Typically, you are going to see cacti, cactus has a thick cuticle, it is able to retain water and0820

they can deal with lack of rainfall for long periods of time.0826

Non succulent shrubs, they are not succulent plants which tend to be very full of moisture.0830

These are shrubs that can deal with the dryness and sagebrush among others.0839

You will see things like Joshua trees in the American Southwest as well, it really depends on the desert you are in.0845

Fauna, the different animals and I’m not going to list all of them but these are some major players.0855

Lots of insect, species, lizards, snakes, running birds like the roadrunner, rodents.0860

I have actually seen kangaroo rats in the wild, I did a study in college where we trap them,0867

in a way that was not harmful to the kangaroo rats.0874

Tagged them and studied the populations of kangaroo rats, they are adorable.0877

Foxes and hawks, you are going to have those top consumers, those tertiary level consumers.0882

That is the desert. Next up is the tundra.0888

Tundra, very harsh environment and you can see that it is concentrated up at the highest latitudes here in the northern hemisphere.0892

Annual rainfall from 20 to 30 cm, temperature range -50° C to a tolerable 12, in the summer months.0900

I put an exclamation point because -50 are you kidding me, it is harsh.0911

It covers approximately 20% of the land mass in the terrestrial sense.0916

You can see that is found at high latitudes and also high altitude.0922

There will be pockets in mountain ranges that really are very much like the tundra at low altitudes.0927

Because it is so high up that you get this freezing soil portions and not a lot of trees and the harsh temperatures.0937

Speaking of the frozen soil, this term permafrost, it is like basically saying it is always super duper cold.0948

Just below the top layer of soil where you have the plant life with its little roots there, beneath that it is always frozen.0958

You are not going to get trees.0967

The fact that there is this permafrost layer that is impenetrable, does not support roots digging into it, 0969

you are not going to see pine trees and large trees.0976

When you look out at the tundra terrain, you are going to see a low lying plant life like mosses0979

which is the most low lying plant you get in kingdom plantae.0987

Lichens which is that combination of the fungus with algae, grasses and low lying bushes.0991

The fauna, the kinds of animals you tend to see, insects, birds, and small and large mammals.1000

It really depends on the specific area. You will see polar bears, you will see foxes occasionally.1006

It really depends on the specific tundra region.1016

The taiga, also known as the boreal forest, also called the alpine forest, also called the coniferous forest.1021

It tends to have conifers, those cone bearing trees.1030

The annual rainfall 30-85 cm, more rainfall than you see in the tundra, than you will see in a desert.1035

The temperature range is not quite as harsh as the tundra and not quite as harsh as the desert, about 10° below 0-20° C.1043

It is the largest terrestrial biome.1052

You can see it covers quite a bit of area in the northern parts of the Americas and the northern parts of Europe and Asia.1056

It is only in the northern hemisphere, interestingly enough.1064

Here is why, if we once again draw a line where the equator is,1068

you can see that the majority of the landmass by far is in the northern hemisphere.1077

There is a lot less in the southern hemisphere.1082

That is another thing that is preventing an extensive taiga from developing down here.1084

Also, it has to do with altitude differences, rainfall differences, and temperature differences down here.1090

The conditions are right up at the northern north hemisphere for the taiga.1098

You can see that it is basically just south in latitude from the tundra.1105

You are going to a point where the soil is not as frozen and you have support of trees.1110

For instance, the flora you see is conifers like pine trees and the like, mosses and lichens.1118

Extensive forests, it is breathtaking going up to the taiga.1124

Fauna, small rodents, lynxes, amphibians, reptiles, birds, and large mammals like moose, bears, and such.1129

Quite a bit of life that is dependent on the taiga.1143

Temperate grasslands, the term temperate refers to the fact that you would see some seasonal changes here.1148

You can see what the range of temperatures, in the winter’s -5 it does get quite cold, 1155

up to room temperature during the summer, that 20°C is quite comfortable.1161

The annual rainfall is more than 25 cm annually but not enough to support trees.1167

Trees depend on a lot of rain to support themselves, their large mass.1176

If you had more rain, we would see those trees but that is what makes it a grassland is you do not see a lot of trees.1183

If there were a lot more trees, it would be a kind of forest.1190

You are going to see very cold winters, when it is that -5 and hot dry summers.1194

You are going to tend to see rainfall not during those summer months.1199

The ability to get by in those hot dry summers until the rainfall comes back in is very important for these organisms.1204

The flora tends to be grasses, short grasses, tall grasses.1213

The fauna, bison or buffalo, you would see those along the great plains in America.1219

Antelope, mice, rabbits, hawks, snakes, batters, coyotes, foxes.1227

You can see in the grasslands, quite extensive in numerous continents.1235

Tropical grasslands tend to be closer to the equator, tend to be around the tropics, also known as a savanna.1243

You can see the one continent that has just extensive Savanna is Africa.1251

That is kind of peoples classic depiction of what this looks like.1256

Annual rainfall, pretty significant 30-150 cm per year.1261

Temperature range, it stays warm year around because you are near the equator 27-30° C.1266

Extensive deep roots in plants, you do have some trees like acacia trees.1273

Part of that is more rainfall than a temperate grassland will tend to get.1279

Not as many trees as a forest, of course.1286

This particular terrain, this particular biome, has the greatest variety of large herbivores of any of the terrestrial biomes.1289

When you consider herbivores are depending on grasses for food, it makes sense.1298

If you got a tropical area where the temperature is pretty stable around, you got a lot of grasses,1304

it makes sense that you have a lot of these big animals depending on a lot of grass to sustain themselves.1310

Flora is mostly grasses.1317

Fauna, here you have the big ones, elephants, giraffes, antelopes, zebras, termites.1319

You are going to see huge termite and ant mounds in parts of the savanna.1325

Lions, hyenas, leopards, you are going to have the animals that are eating the herbivores.1331

Temperate deciduous forest, deciduous forest means it is not evergreen.1341

You will see that term evergreen come up a little later in this lesson.1347

Deciduous means that the leaves do not last year around.1350

The leaves tend to fall off during autumn or the fall.1354

Winter, leafless trees usually and then in the spring that comes back.1358

You see seasonal changes in these temperate deciduous forests.1363

I gave you another busy diagram just to bring us back to the fact that, there is so much variety on planet earth and in these terrestrial biomes.1367

If you are wondering what color is the temperate deciduous forest, this light green is the temperate deciduous forest.1376

Really extensive in parts of the Americas, Europe, and Asia,1383

you can see these temperate deciduous forests in these regions.1388

Rainfall is significant amount to support trees.1391

Temperature range because of that seasonal changed, -30°C up to 30°C on the positive end.1395

Found south of the taiga, that dark green is the taiga.1405

Found south of that is usually and slightly lower latitudes in North America, Europe, and Asia.1409

You can see that here, that dark green is right above and that is slightly higher latitude.1415

Like I mentioned earlier, the trees loses their leaves in autumn or the fall, and they come back in spring.1421

Flora, deciduous trees, these are the trees that lose their leaves, shrubs, mosses, and ferns.1425

Fauna, some tree dwellers like squirrels, rabbits, beavers depending on trees for making their dam,1430

insects, numerous birds, amphibians and frogs.1443

Quite a lot of biodiversities in the temperate deciduous forests.1447

The tropical rainforests, everybody's favorite.1452

The annual rainfall, more than 190 cm annually.1456

On an average day, it is raining.1464

It is raining year around, there are can be days without rain but typically it is raining.1466

Temperature range pretty stable because we are looking at areas that are right around the equator, 20-25° C.1475

By the way, if you are wondering what about up here, what is this, this is not really tropical. 1482

Some of these areas are actually temperate rainforests.1489

The temperate rainforest has quite a bit of rainfall but the temperature is a bit different1499

because since it is not at the equator, it is not tropical.1508

You are not seeing that stable temperature range and that heat exposure year round, 1512

but quite a lot of dense vegetation and rainfall year round in some of these temperate rainforests.1517

When we look at the tropical rainforest, it has the most biodiversity.1524

Scientists estimated that 50% of the earth species, of all species are in the rainforests.1529

There are so many species undiscovered in the rainforest and in the oceans.1534

But of all the terrestrial biomes, there is so much dense vegetation and areas1540

cut off from the ability of scientist to get in there and really identify species.1547

There are so many, probably millions of species undiscovered in the rainforests.1552

Because of that stable temperature, that rainfall year round supports a lot of life.1557

When we look at the levels of the rainforests, there is a forest floor where you get life crawling around,1564

a lot of decomposition on the forest floor.1571

You have a lot of decomposers, fungi, insects, and such, other animals walking around.1573

The ground story is the largest, in terms of like volume of this area.1579

The other story is, once you get up in the trees above the forest floor but not quite to the top of the trees, that is another story.1585

You are going to see all kinds of animals crawling around the trees, frogs, reptiles, monkeys, and insects.1593

And then, when we finally get to the canopy, the canopy is like a living roof.1600

It is going to be very bright up there because you are at the top of the trees.1612

The under story depending on how dense the vegetation is, it can be a little bit darker.1616

The canopy, you are up at the photosynthesis zone.1620

You have a lot of organisms depending on fruits and leaves up there.1625

There is quite a lot of activity at the top of the rain forests.1630

When we look at the flora, evergreen trees meaning they always have their leaves as long as they are alive, evergreen.1634

Eventually they die and they decompose.1642

Epiphytes, these are the plants that end up wrapping around trees and being assisted with their growth,1645

in terms of being able to get up to the sunlight.1653

Epiphytes, they take advantage of the branches and trunks of other trees.1655

Ferns, a very ancient plant form, very plentiful, seedless tree.1660

Fauna, we got numerous insects, birds, frogs, reptiles, mammals, so many to name, so many species.1669

Just to do an internet search of rainforest species, you are going to spend hours.1680

Now, on to the aquatic biomes, when we look at lakes, usually lakes are freshwater.1687

There are saltwater lakes but the majority are freshwater.1692

We can classify lakes by their nutrient status.1695

There are eutrophic lakes and oligotrophic lakes.1698

Eutrophic lakes, nutrient rich, quite an abundance of nutrients available, you are going to see a lot of life in those lakes.1701

You can also have lakes that are oligotrophic, those are nutrient poor.1709

They can become eutrophic through the process of eutrophication.1714

There are various ways that you can get nutrients back into the lake.1719

Sometimes, human intervention can help adjusting species,1723

in terms of like how many particular kind of organism are in the lake can adjust it.1728

What I mean is, sometimes you will get certain organisms having a bloom, they get out of control.1733

Maybe a keystone species, like I have mentioned before in the previous ecology lesson.1742

A keystone species can actually be removed and something it was feeding on gets out of control,1747

in terms of its population density or population numbers.1753

And then, they end up consuming too many nutrients and that can make it where the food web in the lake gets completely altered.1758

The lake can become nutrient poor in the long run.1767

Those are the two kinds of lakes based on the nutrient levels.1770

When we look at the levels of the lake from the top, the surface of the lake, down to the bottom.1774

Let me do this for you, I’m going to do the water in blue, we will do the soil in black.1781

Up here you have got, here is a person, standing up there, and the lake is here.1795

The littoral zone, we will do that in red.1811

Littoral zone tends to be here, right around there, closest to shore.1816

In the littoral zone, you have got rooted plants there hanging out in the water.1823

Clinging organisms to that plant life, protozoans a kind of a protist, invertebrates crawling around there,1828

and fish that can sometimes eat those invertebrates or eat of the plant life in that area.1837

Just below that, the limnetic zone, we will do that in green.1843

This whole area here, this is full of light, it is well lit, that is an exclamation point.1852

This is all well lit and let us say this is a very deep lake.1866

The effectiveness of the light getting really deep, it only can travel so far,1871

in terms of it hitting the bottom is not quite as much light hitting the bottom.1877

But up here, a lot of photosynthesis going on.1882

You are going to have a lot of algae, fish, phytoplankton, and zooplankton.1885

That is the well lit limnetic zone, below that, let us do this in purple, the profundle zone.1892

It is lower, less light, here you going to have a lot of crayfish and mollusks hanging out.1901

Relatives of lobsters and crustaceans like that, mollusks like clams, snails, things like that.1916

You can say that there are some fish down there as well, but it is lower than that well lit limnetic zone.1927

Below that, you are going to have, let us do it in yellow, the benthic zone.1933

Down here, this is the lake bottom, that is the benthic zone and here is a little snap shot of what you can see there.1944

Worms, decomposers, and shrimps, you can have mollusks as well.1953

You will see a few worms and other things eating the bits of dead bodies down there, mostly.1960

Decomposers, that can help recycle nutrients in this particular ecosystem.1967

Estuaries are areas where freshwater and saltwater meet.1978

Typically, it is because a river is coming in contact with the oceans.1982

You get this interesting mix of saltwater and freshwater, and very interesting organisms there.1986

They are also called mangrove swamps, marshes, mud flats, it depends on where you are, they have different names.1992

Organisms in these areas need to be able to deal with varying salinity levels.1998

Because depending on the specific area, depending on how close you get to the ocean water, 2005

how far up you get to where it is more fresh water, you are going to have varying amounts of salt.2010

Depending on how much river water is rushing down, depending on the tide of the ocean,2017

it is going to be altered throughout the day with slightly different salinities.2024

Being able to deal with those changes is very important here.2029

Usually, estuaries can be nutrient traps because the ocean running into it, 2033

the nutrients that are flowing down from the mountains to the river, 2040

they do not all empty into the ocean consistently or effectively.2043

A lot of times you will get nutrients hanging out in these areas and gradually ending up in the ocean.2050

You get nutrient traps and that can be very good for the organisms in this estuary region.2058

Organisms can include phytoplankton, little tiny organisms, plants, fish.2064

A lot of fish spawn in these areas, salmon, we will find in the river that they will spawn in and swim upstream.2069

Oftentimes, through the estuary and up to where it is pure freshwater.2075

Salmon have to deal with that varying salinity because they are going through this area back upstream, and shellfish too.2081

Marine, onto the oceans, when we look at the oceans in terms of the zones, from top to bottom, there are three major zones.2094

The euphotic, I will do that in green, corresponding to algae.2104

The pelagic and the dark abyss, I will do that in black.2109

The euphotic zone, 'eu' meaning trophotic light, it is well lit.2116

The largest concentration of organisms is up there.2122

It makes sense, you got a lot of algae, you got little organisms feeding off the algae, organisms feeding off of that, and so on.2124

A great example of what you would see in euphotic region where it is well lit, is coral reefs.2132

Keep in mind that, when you are away from shallow areas, when you get to the parts of the ocean 2138

that could get really deep, you are going to have euphotic zones without coral reefs.2144

Coral reefs need to be anchored to the level of the sea floor that was beneath it.2149

You will have areas like in the middle of Pacific or middle of the Atlantic, 2157

where euphotic zone is just water, and you will have a lot of organisms there as well.2159

When we look at coral reefs, it is undeniable how much biodiversity you have.2164

This tends to be shallow, warm tropical waters, where you see this.2168

The major organism there is coral, as you see in this picture here are little cnidarians, relatives of sea jellies or jellyfish,2174

little relatives of sea anemones that are like a large apartment complex of cnidarians.2180

They also have zooxanthellae associated with them, with this mutual relationship.2191

This is a kind of algae that helps sustain coral and it is the photosynthesis that makes it have to be in shallow areas.2196

The zooxanthellae are able to do photosynthesis, have oxygen as a waste product that helps out the cnidarians.2206

I have read that zooxanthellae can also help with the toxin levels that sometimes end up in these cnidarians.2214

Sponges, you are going to see those throughout coral reefs, crabs, sea urchins, sea stars, and more, lots of fish too.2223

The pelagic zone, most of oceans volume.2232

If up here you have got the euphotic zone, the pelagic zone is just a lot of area.2235

We can break down the pelagic zone into a few sub zones.2242

The epipelagic, lots of light because it is right below the euphotic but less nutrients than the euphotic zone.2248

Sharks are going to be found there, dolphins, sea turtles.2256

Of course, you will have dolphins and some of these going up into the euphotic.2259

They hang out in the epipelagic quite a bit.2265

The mesopelagic, less light than the epi, you will see shrimp, squid, other fish.2268

Beneath that, you do not have light.2275

We are talking pretty deep here, bathypelagic, you are going to see particular carnivores and scavengers down there.2278

The lower you get, the creepier it gets.2289

By that, I mean the abyssal plain, the abyss, the deepest parts.2293

We are talking bottom of the ocean where it is like over 1000 ft deep, it is insane.2299

In the bottom of the ocean, you have intense pressure because of so much water up above you, and extreme cold temperature.2307

There is never any light at all, the only light down there would be the occasional bioluminescence.2315

Bioluminescence meaning that, you do have some organisms with little bits of bacteria 2325

that they harbor in their body that will make light displays.2335

Sometimes to scare off predators or to attract mates, or to attract prey.2340

But other than the bioluminescence which is not actual sunlight, you do not have light there.2346

One example is, this is actually a drawing, you can find photographs too, this is the vampire squid.2352

Its genus name is vampyroteuthis.2360

Really crazy organism that actually does this bioluminescence in these little areas at the edge of its tentacles, 2363

it has these glowing pockets.2372

It is just really weird creepy looking squid and it is definitely a predator.2375

You can find that in the deepest parts of the ocean.2382

Also, there are just crazy freakish looking fish that look like they are sci-fi, it just looks make believe.2385

But they exist, and some of them have never seen light and will never see light in the abyss.2396

A little consummation summary for you, this is a good way to end biology as a subject because the earth is our home, 2404

the earth is precious and without it, life as we know would not exist.2414

We need to do our best to conserve what is going on, in terms of biodiversity and 2420

to conserve life so that we can be supported and we can also support life.2428

In terms of biodiversity, the number of species on planet earth, it is hard to know exactly how many 2433

but there are probably between 10 to 15 million species on planet earth, that includes bacteria and on up, all the way up to animals.2438

There could even be 100,000,000, it is possible, but this is our best estimate.2452

From what I have read, not quite 2 million species have been cataloged and identified.2458

1 million something species we actually know of, we have names for.2465

We are ways to go, in terms of discovering what is out there.2470

Threatened species versus endangered species.2473

If a species is threatened, it is at risk of becoming endangered.2476

The numbers have been lessened quite a bit.2481

Possibly it has to do with habitat destruction, possibly due to climate change.2484

Oftentimes, it is due to poaching, illegal hunting.2489

Threatened species, if they are not protected can become endangered.2493

This is when they are at extreme risk of becoming extinct.2497

In the last hundred years alone, we have watched various species become extinct.2502

There are rhinoceros species that no longer exist.2508

In the 20th century the Tasmanian wolf became extinct.2513

There are a lot of species that we could have stepped in and helped, but too much hunting, habitat destruction, causes them to go away.2517

What is the point, why even protect them? Survival of the fittest. 2527

If we think about it in selfish terms, some people who were kind of against saving species, 2533

they think if they cannot survive, whatever, we will do what we need to do to survive.2542

But if you think about it in selfish terms, saving these species actually does help humankind.2546

Here is the value of the biodiversity we have out there, medicinal value, if we say goodbye to a lot of these plants and animals, 2553

the kinds of drugs and studies in terms of curing cancer, curing diseases, there is less out there for us to use.2563

Especially with plants, the amount of medicines we have obtained from plant life is astounding.2572

Also research, in terms of how certain animals were spawned to disease and2580

how they deal with illness or viruses has informed us in terms of saving human lives.2586

There are agricultural benefits, in terms of us having crops and us having produce.2593

If all the rainforests gets destroyed, that will be just an incredibly sad thing to happen, in terms of all the biodiversity loss.2603

But just one snapshot, think about cashews, it come from a plant that is found in the rainforest.2611

If all of a sudden you could not eat a cashew, what is that is your favorite nut, it will be sad.2620

There is a lot of cultural benefits to the biodiversity that we have out there.2626

And then consumptive, the products that we obtained to make 2630

what we make as humans in modern day society, we get them from nature.2635

There is consumptive value, in terms of maintaining a level of biodiversity out there, in plants and animals and fungus.2639

Habitat loss, as I hinted earlier it is becoming more of a concern.2646

In terms of us taking from nature without doing it in moderation.2653

Tropical rainforest and coral reefs are the most in danger.2660

There are acres of tropical rainforests being destroyed every day.2664

Coral reefs, the phenomena of the bleaching of coral reefs has come to light in recent years.2669

It has to do with, climate change has to do with what is ending up in the ocean, the temperature rise in the ocean.2678

Overfishing, there is a lot of theories why coral reefs are fading away.2684

There is incredible amount of biodiversity and beauty in those coral reefs, and we should what we can to conserve them.2689

Pollution is a major factor in various biomes being harmed and life forms being harmed.2695

Acid deposition, things we do in our society have exposed a lot of areas to increased acidity.2704

We are also talking about acid rain here.2713

What we put in the atmosphere can end up in clouds and it can end up coming back down to the earth in rain droplets.2715

Eutrophication, I mentioned this earlier, sometimes what we put into the water has drastic effects2723

in terms of nutrient balances with the food webs in various lakes and rivers.2733

Ozone depletion, I have a picture right here.2740

There is a huge hole in the ozone layer that is right next to Antarctica, the bottom of the earth.2743

You can see that the total ozone, in terms of how concentrated it is, if it is purple, it is really low.2752

If we continue to put certain chemicals up at the atmosphere, we will damage ozone which is actually O₃ as molecule.2759

O₂ is oxygen gas but O₃ is 3 oxygen atoms in triangular form that makes up ozone.2768

That is a protective layer, it prevents a lot of radiation coming into the earth.2777

If we had no ozone, life would be in a lot of trouble, we will be in a lot of trouble for sure. 2782

Organic chemicals, waste products from manufacturing and factories.2790

Those in the water supply, in the soil, have had terrible effects on life.2797

Thinking about what we do with our waste and the wastes that accumulate 2803

because of our demand for certain products, is something that we need to think about.2808

Here I have the gray wolf canis lupus, it is definitely endangered, 2813

in terms of the numbers that there are used to be of this awesome animal.2818

Climate change, we got to talk about this.2824

Global warming is definitely being affected by human activity.2826

To what exact agree is debatable, what is not debatable in a scientific sense is that2829

humans are having an impact on the warming of the planet.2836

Some of it is natural, there is a lot of evidence in earth's history that the earth has an actual warming periods and cooling periods.2842

Ice ages followed by very warm periods and back to ice ages.2852

But, it is undeniable that post industrial evolution, we have had an impact on the atmosphere and water, certainly.2858

Greenhouse gases have an undeniable effect on the atmosphere.2868

Here is an explanation here, basically as heat comes into the atmosphere from the sun, 2871

a lot of it is absorbed by the earth's surface and the oceans.2878

But, there is a lot of radiation and a lot of solar energy that ends up 2883

being reflected back in. It is supposed to exit the atmosphere and go back into space.2887

However, some of the infrared radiation is absorbed and re-emitted in all directions by greenhouse gas molecules.2891

You can see that right here in this explanation.2900

The more CO₂ and the more methane we have in the atmosphere,2903

there are other greenhouse gases, the more they trap heat in, and that is the greenhouse effect.2909

One way that we can help lower this number is planting more trees, trees like CO₂ and they soak it up.2916

Methane, this comes from a lot of fossil fuel burning.2924

Overpopulation can contribute to it.2930

It is something to keep in mind, we got to curb the emitting of greenhouse gases into the atmosphere.2934

Polar ice caps, over the last several decades, and other ice areas are melting faster and faster.2941

The more the polar ice caps melt, the more that that solid water turns into liquid water, ocean levels gradually can rise.2948

You got coastal communities, cities, right on the edge of a continent that would be in danger of flooding in the long term.2956

Also the less polar ice caps, the less of that white surface you have on the earth, 2964

the white actually does the job of reflecting solar radiation back into space.2970

The less of that white area, those polar ice caps, the more you actually are going to get the ocean getting warmed up.2976

The more the ocean warms up, the more we are in danger of affecting ocean life in the permanent, unfortunate sense.2986

There is a balance that needs to be maintained.2996

Ocean temperatures are steadily rising.2998

A lot of people have noticed in recent years that weather patterns have gotten crazy.3001

Insane amount of hurricanes, tropical storms, extremely harsh winter, areas where the drought is just out of control.3006

This was predicted and foretold years ago that, as global warming gets more intense and climate change is un curve,3017

in terms of what we can do about it, we are going to cause areas to have extreme drought, 3027

areas to have way more rainfall and storms than is normal.3033

It is not too late but as time goes on, the less we do about climate change, the more out of control it is going to get.3038

But there is hope, education is a big part of it.3046

Thank you for watching www.educator.com.3050