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Dinosaurs Grew Fast and Bred Young
Smivs writes "It is thought that dinosaurs were able to breed before they were fully grown, much like todays mammals. This ensured that they could breed before they were predated in the violent world of the Mesozoic era. Calcium-rich medullary bone, which, in birds, is used to produce egg shells, was found inside the fossilized shin-bones of two specimens: the meat-eating Allosaurus and the plant-eater Tenontosaurus.Sarah Werning and Andrew Lee of the University of California, Berkeley, deduced from growth rings inside the bone that the two females were aged eight and 10, very young for dinosaurs, which lived to about 30. 'This shows us beyond any doubt how fast dinosaurs grow,' said Kevin Padian, a professor at UC Berkeley's Museum of Palaeontology. 'They're growing as fast as big birds and big mammals.'"
Well, some of the folk in Africa believe that AIDS can be cured by having sex with a virgin.
Also, think of the children that got AIDS from their mothers.
A very sad story.
Also from what I remember from studying the Middle Ages in school they had around a 40 year life expectancy which is very similar to the Dinos' life expectancy "two females were aged eight and 10, very young for dinosaurs, which lived to about 30."
Just a note about these two numbers. "Life expectancy" is an average value that takes into account the length of time that everyone lives, regardless of cause of death, and like all averages without any other context this can skew your perception. It's not that people died of "old age" at around 40 (presumably due to the harsh life they lived), they could easily live to be 60, 70, or even older. It's that a huge number of people died when they were very young, dragging down the average. What that 40 year life expectancy is really showing you is the effect of the extremely high infant mortality rate in that period.
Whereas the number for dinosaurs is intended to be more of an "upper bound". I don't know how they figure it, but it isn't meant to be the average lifespan of all members of the species, even those killed young. It's more like, that's about the age of the oldest specimens they've found.
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The odds of getting HIV from a blood transfusion in South Africa is incredibly miniscule, all our blood is tested. The vast, vast majority of infections is via sexual activity. It's definitely safe to say that the majority of that 240,000 got HIV from some form of sexual activity, so I think the point stands.
You're right that when most people say "Life expectancy" they mean at birth. However, life expectancy changes as a person ages, as the remaining amount of time a person will live (on average). To correct for high infant mortality, the life expectancy can be taken at 5 or 10 years. In this case, the numbers indicate that 40 years was excluding the infant morality. Please note, this numbers are when the Black Plague was at its least virulent.
Age Remaining Total 00 31.3 31.3 10 32.2 42.2 20 25.2 45.2 30 21.8 51.8 40 16.6 56.6 60 08.3 68.3 80 03.8 83.8Your ad here. Ask me how!
>> Is that not what I am saying they had many who died very very young and made the rest reproduce like rabbits to compensate for the death.
I have to agree with this statement. Look at family statistics here in the U.S.A. prior to around 1940. Family pictures often show a long line of kids from short to tall. Infant mortality was a very real thing and families were larger back then - pretty much had to be. Heck, after WWII, there was this thing called the Baby Boom to replenish the population.
By the way, rabbits are the perfect example. They reproduce fast and young because they are a primary food animal for many predators. If they didn't reproduce the way they do then they would be extinct.
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