A new study by Swiss scientists revealed why giant dinosaurs in the distant past of our planet to lay eggs the size of small adults.
Data published in the journal Biology Letters bring new information and ways in which mammals and birds were able to survive extinction 65 million years ago.
“Dinosaurs with the highest rate of success in the race for survival were precisely those who have achieved the largest size, because they were not affected by interspecific competition. After mass extinction, dinosaurs have tried again to move to reach a maximum size , the evolution of mammals and birds but not dinosaurs they also allowed the resumption phase gigantism. It is somewhat akin to the current situation, the mammals are the dominant class, and birds simply can not grow bigger than they are. ” explains Dr. Daryl Codron, lead investigator.
Although at present live birds of considerable size, and African ostriches, emus or casuarii, their size is insignificant compared to that achieved by sauropozi dinosaurs. In the study, Dr. Codron and his team at the University of Zurich have used simulations of communities of mammals and dinosaurs of 27 size categories, including largest and smallest species in each group.
While large mammals can give rise to put relatively large size compared with parents, dinosaurs were physically limited by the deposition of eggs. This means that even the largest dinosaurs, which reached a weight of 150 tons, had put very small size compared with parents.
“Dinosaurs giants could not lay eggs on their waistlines as they would be broken simply. Egg shell thickness is limited by natural and practical reasons. Shell egg must not exceed a certain thickness, such as air can not penetrate it, and the embryo is deprived of oxygen and ultimately dies. “concludes Dr. Codron.
Source: Discovery News
We may be in for some pretty bad times if we don’t get our act togeehtr, but AGW is unlikely to lead to actual human extinction. Humans are too adaptable, and there’s too many of us in too many places.But it’s at least theoretically possible. If we keep emitting CO2 at our present accelerating rate, and manage to trip enough positive feedbacks, we could drive temperatures past the point that we, and the life forms that we depend on (crops, food animals, et cetera) could survive. And it’s also possible that some (lower) critical temperature point would be reached at the same time that we exhaust our cheap fossil power, which would leave us fewer resources to fix the problem if we haven’t developed adequate alternative energy in the meantime. This could lead to the collapse of modern civilization, leaving us prey to plagues and other perils. It’s marginally possible that this would leave the remaining human population stressed enough to drive us to extinction.