Homeostatic Disruptions

Summary

In this Biology Essentials video, Mr. Andersen explores the impact of environmental changes on homeostasis, particularly focusing on invasive species like earthworms in North America and the brown tree snake in Guam. He explains how these disruptions can affect cells, molecules, populations, and ecosystems, using examples such as dehydration in humans and the devastation caused by invasive species. The video highlights the importance of maintaining a stable internal environment and the consequences of environmental imbalances.

Takeaways

• 🌍 The script discusses the impact of environmental changes on homeostasis, affecting cells, molecules, populations, and ecosystems.
• 🐛 Earthworms are an example of an invasive species in North America, affecting the ecosystem by altering the forest floor and impacting native plants.
• 🌲 The introduction of earthworms in Minnesota has disrupted the natural balance, as the local flora is not adapted to their presence, leading to an unhealthy understory.
• 💧 Dehydration is a form of environmental disruption that can have severe effects on the human body, affecting blood volume and osmolarity.
• 🚫 There are three types of dehydration: hypertonic (loss of water), hypotonic (loss of solutes), and isotonic (loss of both water and solutes), each with different physiological consequences.
• 🌡 The human body is composed of about 75% water, which is crucial for maintaining homeostasis; a drop to 73% can lead to thirst, discomfort, and other symptoms.
• 🚿 Even a 5% loss of body water can lead to serious health issues like headaches, increased heart rate, and nausea.
• 🌡 At 10% water loss, individuals may experience muscle spasms, skin shrinkage, vision problems, and cessation of urination, highlighting the critical role of water in bodily functions.
• 🐍 The brown tree snake is a notorious invasive species on Guam, causing the extinction of several bird species and disrupting the island's ecosystem.
• 🌴 Invasive species like the brown tree snake can lead to a loss of biodiversity and cause significant ecological and economic damage, as seen on Guam.

Q & A

What is the main topic of the Biology Essentials video number 22?

The main topic of the video is the effect of homeostatic disruptions, which discusses how changes in the environment can have significant implications for cells, molecules, populations, and ecosystems.

Why are earthworms considered invasive in North America according to the video?

Earthworms are considered invasive in North America because they were not originally found there. The last ice age and the retreating glaciers scoured the earth and removed the soil, eliminating the native earthworms.

How do earthworms impact the forests of Minnesota as described in the video?

In Minnesota, earthworms devour the material on the surface of leaves, which is not part of the natural ecosystem. This disrupts the understory of the forest, making it unhealthy as the trees and plants there have not evolved with earthworms.

What is homeostasis and why is it important?

Homeostasis refers to the stable internal environment of an organism. It is important because it allows cells, molecules, and entire ecosystems to function properly. Disruptions to homeostasis can lead to negative consequences for the organism's health and survival.

What are the three types of dehydration mentioned in the video and what are their effects?

The three types of dehydration are hypertonic, hypotonic, and isotonic. Hypertonic dehydration occurs when water is lost, causing blood to shrivel up. Hypotonic dehydration is rare and happens when solutes are lost, leading to red blood cells lysing. Isotonic dehydration involves the loss of both water and solutes, which can be fatal if not addressed quickly.

How does dehydration affect the human body, as explained in the video?

Dehydration affects the human body by causing thirst, discomfort, loss of appetite, dry skin, and constipation at a 2% water loss. At 5% loss, it can lead to headaches, increased heart rate, nausea, and tingling in the limbs. At 10% loss, muscle spasms, shriveled skin, dimmed vision, and cessation of urination can occur. At 15% loss, death can result.

What is an example of an invasive species that has caused significant ecological disruption, as discussed in the video?

The brown tree snake is an example of an invasive species that has caused significant ecological disruption on the island of Guam. It has led to the extinction of several bird species and caused power outages by climbing transformers.

Why are islands particularly susceptible to invasive species problems, according to the video?

Islands are particularly susceptible to invasive species problems because they often have unique ecosystems that have not evolved with certain predators or competitors. When an invasive species is introduced, it can quickly become out of control due to the lack of natural predators and the disruption of the local ecosystem.

What measures are being taken to control the brown tree snake population on Guam, as mentioned in the video?

To control the brown tree snake population on Guam, efforts include trapping and the use of acetaminophen to poison them. The idea of introducing a natural predator has been considered but is not being pursued due to concerns it could lead to other problems.

How does the presence of invasive species like the brown tree snake impact the homeostasis of an ecosystem?

The presence of invasive species like the brown tree snake disrupts the homeostasis of an ecosystem by introducing a new predator without natural checks and balances. This can lead to a rapid decline in native species populations and cause imbalances in the food web, ultimately affecting the overall health and stability of the ecosystem.

Outlines

00:00

🌱 Impact of Environmental Changes on Homeostasis

Mr. Andersen introduces the concept of homeostatic disruptions, explaining how environmental changes can affect cells, molecules, populations, and ecosystems. He uses the example of invasive earthworms in North America, which have been introduced by human activities and are causing significant disruptions to the forest understory in places like Minnesota. These earthworms consume decomposing leaf material, which is not part of the natural ecosystem, leading to an unhealthy environment for native plants. The video also touches on how homeostasis, the stable internal environment of organisms, can be disrupted by environmental changes, with dehydration in humans as a specific example. Dehydration can occur in three forms: hypertonic, hypotonic, and isotonic, each with its own set of serious health implications if not addressed.

05:01

🐍 Invasive Species and Ecosystem Disruption

This section delves into the consequences of invasive species on ecosystems, using the brown tree snake's impact on Guam as a case study. The brown tree snake, introduced to Guam post-World War II, has caused a dramatic decline in native bird populations due to the absence of natural predators. The snake's unchecked proliferation has led to ecological imbalance, with the island's bird species facing extinction. The video also mentions other notorious invasive species like the Common Myna, Cane Toad, and Carp, which are causing havoc globally. The discussion highlights the challenges of managing invasive species, such as the dilemma of introducing a natural predator to control the brown tree snake population on Guam, which could potentially lead to other ecological problems. The overall message is that environmental changes, particularly those caused by human activities, can significantly disrupt the homeostasis of ecosystems.

Keywords

💡Homeostasis

Homeostasis refers to the stable internal environment maintained by living organisms through various physiological processes. In the video, homeostasis is disrupted when environmental changes occur, such as the introduction of invasive species or dehydration. The video explains that homeostatic disruptions can have significant implications at various levels, from cells to ecosystems.

💡Invasive Species

An invasive species is a non-native organism that, when introduced to a new environment, can cause harm to the local ecosystem by outcompeting native species for resources or by being a predator without natural enemies. The video uses the example of earthworms in North America, which are invasive and can disrupt the forest understory by devouring leaf litter, affecting the health of the forest.

💡Dehydration

Dehydration is a condition that occurs when an organism loses more water than it takes in, leading to an imbalance in bodily fluids. The video discusses three types of dehydration: hypertonic, hypotonic, and isotonic. It emphasizes the severe consequences of dehydration on human health, such as increased heart rate, muscle spasms, and eventually death, illustrating the importance of water for maintaining homeostasis.

💡Hypertonic Dehydration

Hypertonic dehydration is a type of dehydration where there is a loss of water relative to the solute concentration in the body. This results in a higher concentration of solutes in the blood, causing it to shrivel up. The video explains that this type of dehydration can occur when an individual does not consume enough water, leading to serious health implications.

💡Hypotonic Dehydration

Hypotonic dehydration is a rare form of dehydration where there is a loss of solutes relative to water, causing the red blood cells to lyse due to the influx of water. The video mentions that this type of dehydration is uncommon but can still have severe consequences on the body's homeostasis.

💡Isotonic Dehydration

Isotonic dehydration is the most common form of dehydration, where both water and solutes are lost in roughly equal proportions. The video describes the rapid and severe consequences of isotonic dehydration, including the breakdown of the circulatory system and eventual death if not addressed.

💡Ecosystem

An ecosystem is a community of living organisms interacting with each other and their physical environment. The video discusses how invasive species can disrupt ecosystems by introducing new predators or competitors that can lead to the extinction of native species, as seen with the brown tree snake on Guam.

💡Brown Tree Snake

The brown tree snake is an invasive species that was introduced to Guam after World War II. The video describes how this snake, with no natural predators on the island, caused the extinction of several bird species by eating their eggs and young, leading to a significant disruption in the island's ecosystem.

💡Circulatory System

The circulatory system is the body's network of organs and vessels that transport blood, nutrients, and oxygen to all parts of the body. The video explains that dehydration, particularly isotonic dehydration, can have severe consequences on the circulatory system, leading to increased heart rate, respiration rate, and eventually, if not addressed, death.

💡Osmolarity

Osmolarity refers to the concentration of solutes in a solution, which affects the movement of water across cell membranes. The video mentions that dehydration affects osmolarity, as the body tries to maintain a stable internal environment. When water loss occurs, the body's osmolarity increases, leading to various physiological responses to restore balance.

💡Environmental Disruption

Environmental disruption refers to changes in the environment that can affect the stability and balance of ecosystems, organisms, or cellular processes. The video uses examples of invasive species and dehydration to illustrate how such disruptions can lead to significant consequences for homeostasis at various levels of biological organization.

Highlights

Homeostatic disruptions can have significant effects on cells, molecules, populations, and ecosystems.

Earthworms are an example of an invasive species in North America due to the last ice age.

Invasive earthworms in Minnesota are causing the forest understory to become unhealthy.

Homeostasis refers to a stable internal environment, and disruptions can affect cells and molecules.

Dehydration is an example of an environmental disruption that can affect the human body.

There are three types of dehydration: hypertonic, hypotonic, and isotonic.

Dehydration can lead to serious health consequences and even death if not addressed.

Water is crucial for life and maintaining osmolarity, and a lack of it can cause circulatory system failure.

Invasive species like the brown tree snake on Guam have caused significant ecological disruptions.

The brown tree snake has led to the extinction of twelve bird species on Guam.

Invasive species can cause power outages and other infrastructure problems.

Islands are particularly susceptible to the effects of invasive species.

The introduction of invasive species can throw off the homeostasis of an ecosystem.

Efforts to control invasive species include trapping and poisoning, but introducing natural predators is a risky strategy.

Environmental changes, whether human-induced or natural, can disrupt homeostasis at various levels.

Transcripts

Hi. It's Mr. Andersen and welcome to Biology Essentials video number 22. This

is on the effect homeostatic disruptions. In other words how changes in the environment

can have huge implications when it comes to cells, molecules, populations and even ecosystems.

And so I wanted to start by showing you a picture of an invasive species. And this invasive

species is something we don't usually think of as invasive. It's the earthworm. What does

that mean? Earthworms in general were not found in North America. And the reason why

is that during the last ice age as glaciers retreated from North America, it scoured the

earth. And as it did that it pulled the soil off. And so it got rid of all of the earthworms

that we have in North America. Now there were some in California and some in the southeast,

but there were generally no earthworms. And so they're really invasive. They don't belong

here. But as the pilgrims came and more recent time as we started bringing soil and

animals and things over, the earthworm established itself. And we're actually helping that problem.

Every time we go fishing and we let some of the earthworms go, we're actually ravaging

some of the forest. And so an example could be in Minnesota. Minnesota's not designed

to have earthworms. And so the problem with having earthworms is that they'll devour the

material on the surface of the leaves, the things that are dying. And normally the

trees and the plants in the forest of northern Minnesota are not evolved to have worms. And

so it's actually making the understory in a lot of the forest very unhealthy. And so

it's a change to the environment. In this case it's a human change. But changes can

effect homeostasis. And so essentially homeostasis is that stable internal environment. Disruptions

then are going to be changes in the environment itself. Now those can affect things at the

level of just cells, individual cells or even individual molecules. An example I'll talk

about is just dehydration in humans. And then they can also have implications when it comes

to larger levels, like the ecosystem. And I'll give you an example of an invasive species

that really shows you the power of changes to the environment. And so let's start with

dehydration. Dehydration, we don't tend to think about it because we always have a steady

supply of water, in general. But dehydration can lead to huge implications very very quickly.

There are actually three types of dehydration. Hypertonic dehydration is when you're just

going to lose water. What does that do to your blood? It's going to cause your blood

to shrivel up. Hypotonic is going to be when we lose solutes. That's rare but it's going

to cause our red blood cells to lyse. Most of the dehydration that we get is when we

lose both water and solutes. And it doesn't take long for us to die as a result of that.

Why is it doing that? Well, we live on land and as a result we have to bring our osmolarity

with us. And we have to maintain that. And water is super crucial to life. And if we

don't have water our circulatory system quickly is going to breakdown. We're eventually going

to die. And so this is a child that is dealing with dehydration after the big earthquake

in Haiti. And some armed service person is helping to give them a little bit of water

at a time. And hopefully bring them back to life. But it doesn't take long to die from

dehydration. And so normally in a human about 75% of our water actually, or our body is

made up of water. So water is polar. It allows it to dissolve material. And so it's

really is the elixir of life. And so most of our body is made up of that. But if we

don't get enough water in our diet, so let's say it drops from 75% to 73%, so we have water

loss, these are some of the consequences of that. We're going to have thirst, discomfort,

loss of appetite, dry skin, constipation. And that's just in a drop of 2%. Now what

is that water loss effecting? It's effecting our blood. It's effecting the tissues in our

body. And so our body tries to accommodate for that. But if you don't have an influx

of water, it's going to be serious really really quickly. And so if that water loss

goes to 5%, then you're going to experience headaches, increased heart rate, as an example

or as a consequence of changes to the circulatory system. Your body is going to crank up its

respiration rate to try to accommodate for that. Nausea. Tingling in the limbs. Just

with the loss of 5%. At 10% you'll get muscle spasms, skin will shrivel up. Your vision

is going to dim and that's because we're going to get an increase in the blood concentration

or the blood pressure. Stop urinating and then you eventually undergo delirium. And

then at 15% you're going to die. As a result of that. And so this is a change in the environment.

In other words we're not getting enough water in. As a result of that the cells are not

going to function correctly. And as a result of the cells not functioning correctly you

will die quickly as a result of that. And so that's an example of an environmental disruption.

Now these organisms here all look pretty cool. Common Myna, the Cane Toad, the Carp, Short-tailed

Weasel. All of these look pretty neat but they are notorious. They're on the list of

a hundred of the worst invasive species on our planet. Now some of those are going to

be fungi. Some are going to be plants. But these are some animals that are wreaking havoc

on our planet. And that's because they're adding to a new ecosystem. In other words

they're being introduced in an area where they normally aren't. And as a result to that,

they normally don't have predators. And things can get out of control really, really quickly.

And so this is a disruption at the level of an ecosystem. One of the probably worst stories

of an invasive species would be on the island of Guam. Guam, after World War II, was a big

part of World War II, but it's now a protected democracy, I think that's how it fits with

us, to place it in the U.S. This is Indonesia. Guam's going to be right up here. And so it's

going to be in the middle of the Pacific Ocean. It's a beautiful island. Had beautiful birds

on it. And it's an island paradise. But unfortunately after World War II, somebody stowed away on

a boat. And this is the brown tree snake. Brown tree snake, it wasn't found on Guam

before then. And once it established itself it just went out of control. There are no

natural predators for that tree snake. And so it quickly could climb up in the trees,

eat the eggs of the birds, eat the birds. And so their populations have plummeted. I think

something like twelve bird species have gone extinct just as a result of the introduction

of this tree snake. The tree snake as a result has bred out of control. I think I read at

one point there are about 100 brown tree snakes per every hectare on Guam. And so it's a huge

number. They're having a hard time getting rid of them. Their causing power outages.

They'll climb up onto the transformers and short them out. And so it's a nasty change

to an island. It's invasive species. As we lose those bird species it's going to be a

change in the inspect species. And so it's thrown the whole homeostasis of an island

kind of out of whack. And so they're trying to trap them. They're trying to use, I think,

acetaminophen to poison them. But what they're not trying to do, is they kind of toyed with

the idea of introducing a natural predator of the brown snake but they're worried that

could lead to other problems. And so islands are super susceptible to invasive species.

But again it's just a change in the environment which is throwing off the homeostasis of either

a cell or a population or even in this case an ecosystem. And so I hope that's helpful.