Comments on: Getting Big Takes Time…Millions and Millions of Generations, Say Biologists http://blogs.discovermagazine.com/80beats/2012/01/31/getting-big-takes-time-millions-and-millions-of-generations-say-biologists/ 80beats is DISCOVER's news aggregator, weaving together the choicest tidbits from the best articles covering the day's most compelling topics. Thu, 24 May 2012 06:56:42 +0000 hourly 1 http://wordpress.org/?v=3.2.1 By: Zachary http://blogs.discovermagazine.com/80beats/2012/01/31/getting-big-takes-time-millions-and-millions-of-generations-say-biologists/comment-page-1/#comment-3435546 Zachary Sun, 05 Feb 2012 01:31:40 +0000 http://blogs.discovermagazine.com/80beats/?p=34549#comment-3435546 I was under the impression that while evolution is a constant process, certain drastic changes can be increased in bottle neck scenarios. How steady is the increase in size over time? I was under the impression that while evolution is a constant process, certain drastic changes can be increased in bottle neck scenarios. How steady is the increase in size over time?

]]> By: Techs http://blogs.discovermagazine.com/80beats/2012/01/31/getting-big-takes-time-millions-and-millions-of-generations-say-biologists/comment-page-1/#comment-3412404 Techs Thu, 02 Feb 2012 11:05:23 +0000 http://blogs.discovermagazine.com/80beats/?p=34549#comment-3412404 Humans in America are getting shorter while most of the rest of the world is still growing taller. Diet seems to be a major part of the reason not immigration. Of course if you measure sideways then Americans are still growing. Humans in America are getting shorter while most of the rest of the world is still growing taller. Diet seems to be a major part of the reason not immigration. Of course if you measure sideways then Americans are still growing.

]]> By: Gary B http://blogs.discovermagazine.com/80beats/2012/01/31/getting-big-takes-time-millions-and-millions-of-generations-say-biologists/comment-page-1/#comment-3410103 Gary B Thu, 02 Feb 2012 03:20:23 +0000 http://blogs.discovermagazine.com/80beats/?p=34549#comment-3410103 At first glance, those numbers seem problematic to me. 24 million generations in 70 million years implies average generations of less than three years. Even discounting the point that elephants and mastodons (for example) have been around for a while themselves. For this to work the vast majority of these generations would have to be multiple generations per year, among tiny mouse-size creatures. Must we assume that 23.5 million of those generations happened in the first 30 million years? OTOH, one characteristic that shows up in many trends in living systems is the inverse power law. So if we apply that to the length of a generation vs. time, then this might just work. IIRC it already has been shown to apply to the size vs. population distribution of mammals. So, maybe after all. At first glance, those numbers seem problematic to me. 24 million generations in 70 million years implies average generations of less than three years. Even discounting the point that elephants and mastodons (for example) have been around for a while themselves. For this to work the vast majority of these generations would have to be multiple generations per year, among tiny mouse-size creatures. Must we assume that 23.5 million of those generations happened in the first 30 million years?

OTOH, one characteristic that shows up in many trends in living systems is the inverse power law. So if we apply that to the length of a generation vs. time, then this might just work. IIRC it already has been shown to apply to the size vs. population distribution of mammals. So, maybe after all.

]]> By: JD http://blogs.discovermagazine.com/80beats/2012/01/31/getting-big-takes-time-millions-and-millions-of-generations-say-biologists/comment-page-1/#comment-3409784 JD Thu, 02 Feb 2012 02:23:07 +0000 http://blogs.discovermagazine.com/80beats/?p=34549#comment-3409784 Elephants and large dinosaurs were created this way, large. They may make some small changes in evolution but nothing dramatic. God creates how he wants except many humans can not fathom this because they don't believe in God. Elephants and large dinosaurs were created this way, large. They may make some small changes in evolution but nothing dramatic. God creates how he wants except many humans can not fathom this because they don’t believe in God.

]]> By: James Harmer http://blogs.discovermagazine.com/80beats/2012/01/31/getting-big-takes-time-millions-and-millions-of-generations-say-biologists/comment-page-1/#comment-3408348 James Harmer Wed, 01 Feb 2012 21:14:16 +0000 http://blogs.discovermagazine.com/80beats/?p=34549#comment-3408348 Why would any future behemoths be scuttling around our feet. Why wouldn't they be us? Look at human size over the last few thousand years, and the trend is towards bigger people... Why would any future behemoths be scuttling around our feet. Why wouldn’t they be us?
Look at human size over the last few thousand years, and the trend is towards bigger people…

]]> By: Sunny D http://blogs.discovermagazine.com/80beats/2012/01/31/getting-big-takes-time-millions-and-millions-of-generations-say-biologists/comment-page-1/#comment-3402217 Sunny D Wed, 01 Feb 2012 01:44:29 +0000 http://blogs.discovermagazine.com/80beats/?p=34549#comment-3402217 Elephants are AWESOMMEEEE!!! Elephants are AWESOMMEEEE!!!

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