Gigantism in the ancient world

[UM-Bot]

http://www.unexplained-mysteries.com/images/newsitems/dinosaursa1.jpg

Fred Flynn: Gigantism in the ancient world occurred in the kingdoms of the insects, plants and animals. It has long been a mystery and topic of conjecture: why were these living things so big, and why not now? Dragon flies with 60 cm. wingspans, dinosaurs, such as the brontosaurus, that surely must have caused the earth to shake as they moved about searching for food and evading predators were the standards for those distant days.

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[+OverSword]

I've never heard that before. Interesting but it doesn't explain how a brontosaur would have kept his neck up or how a giant insects exoskeleton could have supported it's wieght. The alternative explanation which does explain this is the expanding earth theory. If in the past the earth was smaller the gravity would have been less.

Please see video above

[Eldorado]

In times of plenty we get big and fat.

[keithisco]

Uranium has a half life of 4,5 Billion years. Dinosaurs lived in an era (geologically speaking) that ended some 130 million years ago, way before man, but the levels of background radiation from Uranium deposits are largely the same as today.

Radioactive mutations are not dependent on environmental conditions, the DNA gets screwed producing many , many deviant organisms which may arise, but they simply cannot survive.

The premise from the article is that background radiation led to a huge variety of organisms achieving gigantism this is a fallacy, because Gigantism in this respect can only survive if there is sufficient protein resource to sustain it.

You need to be looking at other mechanisms for an answer to the Gigantism during the Jurassic, and cretaceous periods. Might be better to look at gas concentrations in the atmosphere, climatic conditions etc because high levels of radioactive particles would not affect each organism in the the same way and produce viable "giants" without other influences..

p.s. "Brontosaurus" became "Apatosaurus" many, many years ago because it was incorrect.

Edited August 28, 2012 by keithisco

[Order66]

We have directly observed how gigantism has been caused by radiation

Several examples in fact come to mind ...

[jbondo]

I was under the impression that it was due to much higher levels of oxygen.

[Hawken]

In times of plenty we get big and fat.

Agreed. We're much bigger and taller then our ancestors 100 years ago. So maybe dinos had plenty to eat.

[Yamato]

Humankind has only been around for a million years give or take, but as the planet's dominant species we're too getting bigger and bigger by the century, radioactivity not required. Fuel (food, oxygen) grew the dinosaurs big, and ironically their massive energy requirements made them all dead as environmental catastrophe wouldn't allow adequate fuel for creatures as large as dinosaurs to survive. Abundant food sources are certainly required to sustain giants like dinosaurs or whales yet there would still be substantial environmental constraints on population sizes due to their enormous size. Mammals had much lower energy requirements to subsist and so rose to global prominence. I would guess there is a very high correlation between population growth rates of a species and increases in that species' average body mass through time.

[CRIPTIC CHAMELEON]

Agreed. We're much bigger and taller then our ancestors 100 years ago. So maybe dinos had plenty to eat.

I do remember reading somewhere it has got to do with abundance of food and climate, but if you look at Homo Heidelbergensis this fellow averaged 1.8 [6.0ft] to 2.13 [7.0ft] tall and a lot more muscular then modern humans so anything is possible.

[egyptian lad]

Humans were also gigantic in the early ancient times, its what the archaeologists hide untill todays.

Dinasour and giant animals lived in the same age of giant humans, In ancient egypt some depicted scenes prove this logical theory.

Giant horses and Giant cows were recorded on the reliefs, people were small under their legs.

Plus: several accounts of egypt giant human portraits is everywhere on the gigantic temples

[FreddyScienceTeacher]

One reader replied that is takes 4,5 billion years for uranium to decay into lead, which is incorrect. U-235 becomes lead at 700 million years (bingo timeframe). U-238 takes 4.5 billion years to decay....

[Rlyeh]

One reader replied that is takes 4,5 billion years for uranium to decay into lead, which is incorrect. U-235 becomes lead at 700 million years (bingo timeframe). U-238 takes 4.5 billion years to decay....

As U-238 is the most common isotope I'm going to have to agree with them. U-235 makes up less than one percent.

http://education.jlab.org/itselemental/ele092.html

[Dragonwind]

I was under the impression that it was due to much higher levels of oxygen.

And I believe humidity/moisture. Why giant redwoods are found in PNW.

[cacoseraph]

Gah, this article actually caused me physical pain.

No real science was presented, no studies cited, no actual real theories of how things work put forth.

Back in the day, bugs got bigger cuz of more oxygen. The mechanisms are well understood in the bug community and we can even make bigger bugs in hyperoxygenated chambers today, Maybe this affected higher animals, but maybe things just shook out different for them back then. Elephants are not the theoretical max size terrestrial organisms AND blue whales ARE the biggest known living animal organisms EVER. So, hooey on the bulk of this unsupported article.

[cacoseraph]

And I believe humidity/moisture. Why giant redwoods are found in PNW.

I would actually say lower average temps. It doesn't allow for kill bugs to develop as easily. If RH was king we would find the giants more equatorial, but they are definitely temperate.

Edited September 3, 2013 by cacoseraph

[ZakCarter]

Well, if radioactivity was the cause of gigantism, I guess it's a good thing Japan is building that ice wall!;p

[No Censorship]

Agreed. We're much bigger and taller then our ancestors 100 years ago. So maybe dinos had plenty to eat.

That's true. We might be a bit shorter than northern European people during a certain time in the Dark Ages, though. I think that it was in the 800s or 900s. History shows that heights fluctuate.