Insects in High Oxygen Environments

I have read a couple articles that have said that the reason that we do not currently have large insects on this planet, is because the oxygen levels are too low to support their type of respiratory systems. There is fossil records of insects that are much larger during a time when the oxygen levels were much higher.

My question is, are there any scientists that are studying or running expiriments in which they subject multiple generations of insects to a controlled, high oxygen environment, possibly selectively breeding for size to see if it is possible to produce insects that are much larger than we currently see?

Thoughts?


Insect Body Size


Bugs of the Past

reply to post by iamcamouflage


Um, yep. I tiny-fied some of the huge URLs. But here are a ton of experiments regarding that hypothesis. If you need help interpreting, let me know or U2U me.

/kr6m9h

Not sure how this is a conspiracy though. Here's some info:

Background
The correlations between Phanerozoic atmospheric oxygen fluctuations and insect body size suggest that higher oxygen levels facilitate the evolution of larger size in insects.
Methods and Principal Findings
Testing this hypothesis we selected Drosophila melanogaster for large size in three oxygen atmospheric partial pressures (aPO2). Fly body sizes increased by 15% during 11 generations of size selection in 21 and 40 kPa aPO2. However, in 10 kPa aPO2, sizes were strongly reduced. Beginning at the 12th generation, flies were returned to normoxia. All flies had similar, enlarged sizes relative to the starting populations, demonstrating that selection for large size had functionally equivalent genetic effects on size that were independent of aPO2.
Significance
Hypoxia provided a physical constraint on body size even in a tiny insect strongly selected for larger mass, supporting the hypothesis that Triassic hypoxia may have contributed to a reduction in insect size.

www.pubmedcentral.nih.gov...




That was just a quick Google search. I'm sure there are tons more studies.

/mqdzmx

Here's more

Most terrestrial insect embryos support metabolism with oxygen from the environment by diffusion across the eggshell. Because metabolism is more temperature sensitive than diffusion, embryos should be relatively oxygen-limited at high temperatures. We tested whether survival, development time and metabolism of eggs of a moth, Manduca sexta, were sensitive to experimentally imposed variation in atmospheric oxygen availability (5–50 kPa; normoxia at sea level is 21 kPa) across a range of biologically realistic temperatures. Temperature–oxygen interactions were apparent in most experiments. Hypoxia affected survival more strongly at warmer temperatures. Metabolic rates, measured as rates of CO2 emission, were virtually insensitive to hypo- and hyperoxia at 22°C but were strongly influenced at 37°C. Radial profiles of PO2 inside eggs, measured using an oxygen microelectrode, demonstrated that 3-day-old eggs had broad central volumes with PO2 less than 2 kPa, and that higher temperature led to lower PO2. These data indicate that at realistically high temperatures (32–37°C) eggs of M. sexta were oxygen limited, even in normoxia. This result has important implications for insect population ecology and the evolution of eggshell structures, and it suggests a novel hypothesis about insect gigantism during Paleozoic hyperoxia.

More:

Abstract. 1. Oxygen consumption was determined for ninety-three taxa of desert-inhabiting arthropods of various life stages over the temperature range 10–40C. Regression analysis of O2 consumed/individual/h on the mean dry weight of individual adult insects yielded a slope of 0.70 (r= 0.87) while the same analysis for non-insect arthropods gave a slope of 0.74 (r - 0.87).

/ku57u9



[edit on 7/24/2009 by ravenshadow13]

reply to post by iamcamouflage


Insects can NOT be trained or tamed, they are purely instinctive, they are very very well adapted to defence and to killing, they are unimaginably strong and extremely fast and agile. They also breed so fast that they populate areas literally overnight.

Imagine one as big as a dog. Not a good idea to 'make' one is it?

[edit on 24-7-2009 by NathanNewZealand]

reply to post by NathanNewZealand


Still the vet bills would be low.

Originally posted by NathanNewZealand
reply to post by iamcamouflage

 

Insects can NOT be trained or tamed, they are purely instinctive, they are very very well adapted to defence and to killing, they are unimaginably strong and extremely fast and agile. They also breed so fast that they populate areas literally overnight.

Imagine one as big as a dog. Not a good idea to 'make' one is it?

[edit on 24-7-2009 by NathanNewZealand]

I am only speaking of attempting this in a controlled environment. If you produced a larger than normal insect in a controlled, high oxygen environment, you would not have to worry if it escaped, because once this insect ventured out in the normal atmosphere, it would be incredibly oxygen deprived and would most likely suffocate and die.

There would just not be enough oxygen in the earth atmosphere to support its biological processes.

I also remember reading somewhere that the gravity on earth would prevent insects from getting to gigantic sizes as well. Something about the ratio of the body size to the size of most insects legs. They would not be able to support their own weight with their current proportions and structure. Not sure if this is true.

reply to post by iamcamouflage


/nkpejw

This Google Book on the Biomechanics of Insect Flight says that gravity plays a part in it. I think so, too. Chitin (what makes an exoskeleton) is super super heavy. If the insects were very large, they would have trouble moving.

Originally posted by iamcamouflage
My question is, are there any scientists that are studying or running expiriments in which they subject multiple generations of insects to a controlled, high oxygen environment, possibly selectively breeding for size to see if it is possible to produce insects that are much larger than we currently see?

Thoughts?

I have the same thoughts as this guy:

Originally posted by NathanNewZealand
reply to post by iamcamouflage

 

Insects can NOT be trained or tamed, they are purely instinctive, they are very very well adapted to defence and to killing, they are unimaginably strong and extremely fast and agile. They also breed so fast that they populate areas literally overnight.

Imagine one as big as a dog. Not a good idea to 'make' one is it?

[edit on 24-7-2009 by NathanNewZealand]

I say we should just all be thankful that insects are small enough to only be a mild annoyance, instead of a major threat.

reply to post by iamcamouflage


Havent posted to this thread in awhile but I was thinking it would be cool to experiment with this high O2 idea. I could catch a fly and put it in enclosed glass tank. I could let it lay eggs in some rotting food, and then funnel extra O2 into the tank while the maggots develop and continue as they become flies. It would be interesting to see if they ended up larger than a normal fly in this environment.

This would be an easy experiment as getting insects and pure O2 is also not a big issue.

I'll report back if I follow through.



[edit on 13-8-2010 by iamcamouflage]

Hello there thanks for the info on the Congolese Spider thread! It led me here and beyond! Good luck with the experiment above too! ^^^

My only advice is it may require several generations of the flies to see visible results? But I am no expert.

Originally posted by iamcamouflage

Originally posted by NathanNewZealand
reply to post by iamcamouflage

 

Insects can NOT be trained or tamed, they are purely instinctive, they are very very well adapted to defence and to killing, they are unimaginably strong and extremely fast and agile. They also breed so fast that they populate areas literally overnight.

Imagine one as big as a dog. Not a good idea to 'make' one is it?

[edit on 24-7-2009 by NathanNewZealand]

I am only speaking of attempting this in a controlled environment. If you produced a larger than normal insect in a controlled, high oxygen environment, you would not have to worry if it escaped, because once this insect ventured out in the normal atmosphere, it would be incredibly oxygen deprived and would most likely suffocate and die.

Hopefully so, but controlled experiments have gone wrong:

science.discovery.com...

In 1957, in a remote laboratory in Brazil, a controlled experiment went horribly wrong. Killer bees began invading the U.S., claiming thousands of lives and advancing at 15 miles every month. Learn how this lethal force of nature is an increasing threat.

Oh and it involved insects too! What if as a result of the lower oxygen they can only move more slowly, and might not instantly die? And in colder temperatures they metabolize more slowly as stated in the post above, so that might also help them survive, maybe.

I also remember reading somewhere that the gravity on earth would prevent insects from getting to gigantic sizes as well. Something about the ratio of the body size to the size of most insects legs. They would not be able to support their own weight with their current proportions and structure. Not sure if this is true.

Apparently that's not exactly true, check out this giant "dragonfly":

Meganeura monyi was a prehistoric insect of the Carboniferous period (300 million years ago), resembling and related to the present-day dragonfly. With a wingspan of more than 75 cm (2 feet) wide, it was the largest known flying insect species to ever appear on Earth.

Originally posted by iamcamouflage
I could catch a fly and put it in enclosed glass tank. I could let it lay eggs in some rotting food, and then funnel extra O2 into the tank while the maggots develop and continue as they become flies. It would be interesting to see if they ended up larger than a normal fly in this environment.

The extra O2 should ALLOW them to get larger, however I'm not sure it will CAUSE them to get larger. I suspect what happened in the data previously posted in the thread is that normal statistical size variation in successive generations is what allowed the larger insects to prosper. So I suspect it might take quite a few generations, like maybe 10 generations at least for a noticeable effect, to see the genetic variation effects multiplied with survivability of the larger insects.

*edit* wrong post...

[edit on 14-8-2010 by harrytuttle]

Just thought I would insert the info this thread was missing. The OP was right.

High Oxygen Levels Spawn Monster Dragonflies

During the Paleozoic era, around 300 million years ago, huge dragonflies zipped around with wingspans stretching more than two and a half feet, dwarfing modern relatives. Back then, however, the planet’s atmosphere had roughly 50 percent more oxygen than today.

To explore the effects of ancient oxygen levels, VandenBrooks’ team raised 11 other “living fossils,” including beetles and cockroaches, in three habitats with different oxygen concentrations — one at the late Paleozoic’s 31 percent oxygen level, another at today’s 21 percent level and the third at 12 percent from 240 million years ago (Earth’s lowest oxygen level since complex life exploded onto the scene half a billion years ago).


They found that dragonflies and beetles grew faster, as well as bigger, in a high-oxygen environment, while cockroaches grew slower and remained the same size. All but two bug species grew smaller than normal at low concentrations of oxygen.

Dragonflies in the modern habitat grew normally, with wingspans of about 3.5 inches, while the hyperoxic chamber spawned dragonflies with 15 percent larger bodies and 4-inch wingspans. Beetles also grew proportionally larger but, conversely, cockroaches didn’t swell to monsters in rich oxygen levels. Instead, they remained the same size and developed more slowly.

www.wired.com...


The only thing I disagree about is the researchers assumption that the organs associated with respiration were smaller and thus the body size could be larger. While the organs were smaller, I think that the energy required to breath was instead spent on other cellular activities resulting in more cellular reproduction. The size of respiratory organs is a side effect of not needing large ones. The Primary effect would be less energy consumption for respiration.

I would also argue that higher oxygen levels would exist with an increased pressure as well. A natural Hyperbaric environment with more oxygen and at greater pressures would increase all life in size. The excess energy would be spent on cellular reproduction. Also I would argue that since it is known that hyperbaric chambers increase cellular efficiency, that cellular toxicity was also lower in early life on earth, resulting in longer life spans. These longer life spans resulted in more time to grow.

I know its an old thread, but the OP was right and I love this subject.

Originally posted by BIHOTZ
I would also argue that higher oxygen levels would exist with an increased pressure as well.

What is the basis for this assertion?

I would think the increased pressure would act as a limiting agent.

So if you give bugs a denser o2 concentration in the atmosphere they get larger. I am glad I live in only 21% o2. I do not want to run into a black widow thats a meter across.

That being said anybody know what the deal is with those giant centipedes that grow to be 2 feet long and can eat just about anything? What's their breathing apparatus like that makes it so different enough that it can grow to that size. Curious.

Originally posted by BASSPLYR
That being said anybody know what the deal is with those giant centipedes that grow to be 2 feet long and can eat just about anything? What's their breathing apparatus like that makes it so different enough that it can grow to that size. Curious.

You mean this centipede that's about 10 inches long and can get as large as 12 inches long or larger?

The simple answer is that length isn't a problem for insect respiration. The oxygen doesn't need to travel from the front to the back, it only needs to travel along the skinny thickness through the trachea.

www.nap.edu...

It is the insect respiratory system that dictates maximum size, it seems. All insects use a system of fine tubes called trachea. Air diffuses into the tissues from these tubes, and air is actively ventilated into the tubes. Either by the insect’s rhythmic expansion and contraction of the abdominal region, or by the insect’s flapping of its wings to create air currents around the tracheal opening, air is pulled into the canals. The tracheal system is fantastically efficient in either case.

reply to post by Arbitrageur


It has been proven that our bodies and that of most living things are more efficient when inside a hyperbaric chamber. Cells regenerate faster and process oxygen more efficiently. By design life on earth is better when inside a highly pressurized environment. Like ice skates are designed for ice travel and not hiking. I would think that having more oxygen would favor better processing in development.

IMO the atmosphere of earth maintained its high oxygen levels consistently for our bodies to use by having increased pressure which our biology favors.

I see them going hand in hand. Less pressure and less oxygen makes for bigger lungs like those of people who live at high altitudes. The pressure would not favor large lungs since it would act against them filling. It would allow for more efficient processing on a cellular level and require smaller lungs which would leave more energy spent on mass growth over organ development. The more organs must grow and develop the less energy that organism can dedicate to other cellular functions during critical development.

I see the current size of life as a reflection of both oxygen concentration as well as pressure imposed to counteract filling the breathing apparatus of a living being. Too much energy being exerted for every breath would limit lung size based on that pressure. I take notice that since on a cellular level our biology would be more efficient and so could do more with less.

My theory anyways. That is why if these insects were in both types of environments their smaller organs would allow more growth by not being limited by poor cellular efficiency once oxygen is in the blood stream. The insects in the article grew but not like they could have since they were still processing oxygen at a reduced rate than what their physiology allowed.

I sure am glad the CO2 levels are rising. The mosquitoes should be getting smaller in the future.

Originally posted by BIHOTZ
My theory anyways.

Thanks for the clarification, but without data it sounds more like a hypothesis than a theory. I'm curious about that though so I'd like to see pressure data if there is any.

Ice core samples go back perhaps 1 million years and trapped gas bubbles give us samples of atmospheric composition for that time period. But 300 million years ago when the giant insects lived, it seems there is more guesswork on atmospheric composition and pressure. Experiments can show what is possible but don't necessarily show what happened, since any number of combinations of higher oxygen and/or higher pressure could have supported larger insects. For example if the portion of oxygen was identical to today, but the pressure was twice as great, creatures would have access to twice as much oxygen. Or if the percentage of oxygen was double what it is today, but the pressure was exactly the same, creatures would have access to twice as much oxygen. Modern experiments may suggest larger insects 300 million years ago needed one or the other or some combination, but they can't pin down anything specific.

reply to post by Arbitrageur

Here is a little about high and low level pressure and oxygenation on the body. While these traits, like that of having a smaller lung for low altitude/ higher pressures or being short and stout are adaptations to environment I say they are indicative of how our body responds FROM its original setting. High pressure systems usually associate with clear skies and nice weather.

The need to favor short and stout like the body does with preserving heat would not be indicative of the result of air pressure or even oxygenation but rather cold weather for low pressure systems that are known for lousy, cloudy weather. Darker skin pigment from higher exposure to the suns radiation from clear skies are not indicative of high pressure either since they are simply dealing with the lack of clouds in a high pressure system. Being tall and lanky is better for hot weather, not for getting more air.

That is why I do not see the particular traits of a species to be indicative of the maxim of environment, instead I see it as dealing with the particulars. What I see with a fundamental change in oxygen content and pressure I associate with it is that the earth may have produced larger species as a result of high pressure systems all over the globe.

Those high pressure systems going hand in hand with really warm weather as they are known to produce. If the whole planet was allot warmer like we have come to accept, then it is only logical that the worlds habitats were mostly high pressure systems. This with our knowledge of the earth having a richer oxygen content would explain why all life from plants to fish were bigger. This combination might be the natural state our original species worked from to produce our current populations.

It is not worthy that people at different altitudes in different places like Tibet or the Andes all have made different adaptations to keep their blood oxygenated. This shows that they were working from a common starting point since the standard their new physiology favors falls under the same standards of cellular oxygenation.

Also note worthy is that in just 3000 years the Tibetan people have made their adaptations showing possibly the fastest case of evolution ever known. Now take that model and stretch it over millions of years and you have a possible root cause for evolutionary adaptation. A direct trigger over food supply or predatory threats.

If the earth does warm again and develop high pressure systems again, I ASSUME oxygen content will increase as plant size increases, causing a cycle of increasing growth in mass for all species. Adaptations will favor warmer weather and so we will see fast changes in evolution....some we might have ourselves.

Hyperbaric Oxygen Therapy (HBOT) has been used for over a century to treat almost all types of injuries, such as stroke, Cerebral Palsy, gangrene, and non-healing wounds. Now, even more recent clinical and university studies have shown HBOT supports the body’s production and mobilization of mesenchymal stem cells. Oxygen works on our stem cells on several different levels. HBOT mobilizes MSC’s from our bone marrow by a nitric oxide (NO) dependent mechanism we call NO synthesis. Nitric oxide is a chemical our body produces that is used as a signaling molecule.

Once the MSC’s get to where they are directed to go, they differentiate into more specialized cells and begin to heal damaged cells. HBOT supports this process and also delivers oxygen needed to facilitate and sustain cell repair.

www.stemcellmd.org...

Hyperbaric oxygen therapy (HBOT) is medicine's most efficient method of transporting oxygen to cells throughout the body. When you breathe oxygen at normal atmospheric pressure, it is transported on the hemoglobin in your red blood cells. Under pressure, however, oxygen dissolves in the plasma, cerebrospinal fluid in the brain and spinal cord, lymph, and other body fluids. It is therefore easily delivered to all tissues, and even areas with limited blood flow are afforded the tremendous healing benefits of oxygen.

HBOT also curbs infection, by providing a hostile environment to anaerobic bacteria, which thrive in the absence of oxygen. It promotes the growth of new capillaries and blood vessels to areas with poor circulation for cardiovascular support and boosts collagen formation for faster wound healing. It also mobilizes rejuvenating stem cells

www.whitakerwellness.com...

Air pressure is not uniform across the Earth however. The normal range of the Earth's air pressure is from 980 millibars (mb) to 1050 mb. These differences are the result of low and high air pressure systems which are caused by unequal heating across the Earth's surface and the pressure gradient force.

geography.about.com...

When we breathe in air at sea level, the atmospheric pressure of about 14.7 pounds per square inch (1.04 kg. per cm.2) causes oxygen to easily pass through selectively permeable lung membranes into the blood. At high altitudes, the lower air pressure makes it more difficult for oxygen to enter our vascular systems. The result is hypoxia , or oxygen deprivation.

anthro.palomar.edu...

In contrast, the native high-altitude resident has a blunted hypoxic ventilatory response (ie, is desensitized) to hypoxia. Improved oxygen usage in the peripheral tissues with decreased ventilatory effort has been postulated as an explanation for this phenomenon. Studies of high-altitude residents showed that for desensitization to occur, exposure to high altitude must occur in early childhood and last several years. The decrease in hypoxic ventilatory response is first noted after 8 years of age. At the same time, vital capacity increases correspondingly.

After desensitization to hypoxia has occurred in the high-altitude resident, it persists for years, even if the person returns to sea level. Offspring of lowlanders born and raised at high altitude have the same phenomenon as that of native highlanders. The native highlander hyperventilates compared with the lowlander, and the high-altitude resident hypoventilates compared with the newcomer to altitude.

emedicine.medscape.com...

evolution.berkeley.edu...


I would argue that the earth once had a general uniformity in weather, and in pressure as well as oxygen content. I say that when that started to change as the weather got colder, that we saw the explosion in species evolutionary change branching off as well as the reduction in size.

I say that our current model of varying weather across the globe in its many extremes has caused our different traits in species being permanent once global weather stabilized. I also say that once it begins changing that we will see the greatest jumps in evolutionary change due directly with processes on the cellular level and their efficiency in different environments.