Why is Lucy so small?

Giant wombats have been found in australia the size of smal cars, carbon dating has them at 40,000 years ago



Before that we have ginat lizards (dino's)

Giant spiders mega-rachne servani with a 1.5ft body and 3ft leg span



giant centipededs and roaches



Giant dragonflies with a wing span of 50 inches.



Gignatic sharks (charcharicadon megaladon up to 50ft long)



These have all been found



The reason why they get so big, is because their enviroment and atmosphere was able to support creatures of that size.



Extra oxygen enabled the creatures to get big

extra c02 enabled the plants they eat to get big.



Sotherefore if up to 40,000 years ago we the environemt had enough oxygen to grant big wombats, what would have happened to all other creatures living at that the time.



The extra oxygen and c02 would have been available for all creatures meaning you would still get pretty big lizards.



Also if Lucy is found at 3 million years ago, the extra oxygen should have turned her into a giant too

Why is Lucy so small?
Frankly, your creationist copy and pasted arguments are starting to get frustrating. What you're looking for is a religious debate, not a scientific one - if you want that, please redirect your questions to R%26amp;S.
Reply:It's a matter of economics. Lucy's smaller size made the available food supply that much greater. Life wasn't easy for Lucy and her kin. Being big works only when the food supply will support it. Being 9 feet tall and muscular would have helped against predators but Lucy made up for this by virtue of the greatest brain ever to appear on the planet. Her and her kind would eventually master fire and weapons and things like agriculture and the domestication of livestock, which freed her from the hunter-gatherer lifestyle that had severe limitations.
Reply:in a way she was a giant, just compare her to the size of other primates of the same time period. average was about 2.3 feet tall for any bi-pedal primates, while Lucy was over 3 feet tall
Reply:The giant wombats were able to evolve because they were in an environment with abundant food and little or no predators. It had nothing to do with oxygen levels.



The dinosaurs, likewise had nothing to do with oxygen levels, but available ecological niches. While some of them were very large, there were also many dinosaurs which were much smaller - down the size of chickens.



The giant spider has been more accurately identified as a type of sea scorpion - it was not terrestrial, but lived in the ocean (where water can support larger body sizes for arthropods). It wasn't even large for a sea scorpion.



The giant centipedes and roaches that existed were not appreciably larger than the species we have now - at most a foot long.



The giant dragonflies lived about 300 million years ago (not 3 million) - at a time when there was more oxygen in the atmosphere, and (more importantly) no birds or pterosaurs to eat them.



Giant sharks existed in the seas - again, where water can support larger sizes. It had nothing to do with oxygen levels. There were also (and continue to be) many, many species of sharks which were smaller than Megalodon.



At 3 million years ago (and even 6 to 8 million years ago, when Lucy was around) the oxygen levels were pretty comparable to what they are now.



Lucy is almost exactly the same size as a chimpanzee. Which is not all that surprising when you consider their common ancestry.



Oxygen doesn't automatically turn creatures into giants - increased size is just one possible adaptation to environments. Although it can confer advantages in some situations, and lead to animals that are bigger and larger than their ancestors, it also has disadvantages (more food required, greater structural support needed) that can favour smaller organisms.
Reply:Not everything that existed 3 million years ago was gigantic. There were small animals that existed back then as well. Your theory is based on false premises. Diet is more important to size than oxygen intake.
Reply:idk i wasnt alive then gosh

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