"Hot Weather Makes Mammals Smaller, So Will Global Warming Make Us Shrink?"

[Ðekel]

found on Popular Science, here;
http://www.popsci.com/science/article/2012-02/hot-weather-makes-mammals-smaller-%E2%80%94%C2%A0what-does-mean-global-warming

i found this interesting.
especially since this information, if correct, indicates that larger humanoids fit more naturally in colder environments.

 

[bngenoh]

Interesting transientP:

In about three-quarters of mammals, a truism called Bergmann’s rule holds that animals are smaller in hot climates and bigger in cold climates. Think about wooly mammoths versus Madagascan tenrecs. But a debate persists about why this is so, and whether it’s because of temperature itself or because of indirect results, like food abundance and conservation of heat energy. Ross Secord and colleagues set out to answer this question by studying horses from now and in the past.

While other factors probably need to be taken into account, like gravitational changes, genetic mutations possibly initiated by the same cause, etc. Maybe the ice age conditions that saw the existence of such huge creatures as Woolly Rhinos, giant wolves, etc was merely an effect, and not the cause, the cause lying outside of earth.

 

[herondancer]

found on Popular Science, here;
http://www.popsci.com/science/article/2012-02/hot-weather-makes-mammals-smaller-%E2%80%94%C2%A0what-does-mean-global-warming

i found this interesting.
especially since this information, if correct, indicates that larger humanoids fit more naturally in colder environments.

I wonder how they would square that with the idea that Arctic-dwelling peoples tend to be short and stocky to preserve body heat? And that Africa contains both very tall peoples living in Sudan, like the Masai and others, plus the pygmy race? Seems like more global warming propaganda from PS.

 

[Ðekel]

I wonder how they would square that with the idea that Arctic-dwelling peoples tend to be short and stocky to preserve body heat? And that Africa contains both very tall peoples living in Sudan, like the Masai and others, plus the pygmy race? Seems like more global warming propaganda from PS.

i was thinking this as well, although it makes sense that it has a LOT to do with genetic variation within a given species.
some animals have far less variation in size within their own genotype. meaning that even if the stockier members of its group survive, there is almost no change over time in regards to size.

While other factors probably need to be taken into account, like gravitational changes, genetic mutations possibly initiated by the same cause, etc. Maybe the ice age conditions that saw the existence of such huge creatures as Woolly Rhinos, giant wolves, etc was merely an effect, and not the cause, the cause lying outside of earth.

this is closer to what i was thinking. in Science, in general (and in Paleontology in particular) there since to be a close-minded strategy of finding the ONE cause and linking things by "cause" & "effect" too linearly.
i think what you're pointing to is a thought that would do most researches very well to keep in mind.

 

[Ben]

It's also a massive oversimplification because size is dependant on so many factors. The three largest land mammals all occur in Africa, which isn't exactly chilly overall. The example they chose of the madagascan tenrec is problematic for their theory - 'island dwarfism' is a well known phenomenon in which animals on islands evolve to be smaller due to the lack of food compared to their mainland counterparts.

The key to preserving body heat is a high surface area to volume ratio ie. short and stocky rather than tall and thin as herondancer pointed out. Plus, when you factor in the big brained humans, all bets are off when it comes to temperature regulation. Makes you think about just how cold it has to get for natural selection to favour a certain human body type when humans can insulate themselves so effectively anyway. That is of course, unless some other force has dictated the development of the different human forms....