Today we will go over Chapter 10; we are reading one chapter a week.
I encourage this to be slow blogging - the very opposite of "breaking". I will leave this on my hot list for a week, so comment any time during the week.
When we get near the end of GGS, I'll start a poll for the next book; I am strongly leaning towards the book Ideas: A history of thought from fire to Freud.
Ground rules: I expect vigorous discussion. But I expect civil discussion. A sign I saw in a restaurant said
Be nice or leave
In previous chapters, Diamond discussed the origins of agriculture and of animal husbandry, and why they were more likely to happen in Eurasia than other continents. In this chapter, he discusses why agriculture, in particular, spread more quickly in Eurasia. The main point is simple: Eurasia lies mostly on an east-west axis, while Africa and the Americas are mostly on a north-south axis. Plants spread more easily from east to west (or vice versa) then north to south (or vice versa).
The reason is that plants are adapted to cycles of day/night (which are constant east to west) and climate (which does vary east-west, but varies more, north to south).
Of course, climate does vary, even at the same latitude - and Diamond recognizes this, pointing out that, e.g. Texas and Arizona lie between relatively similar climates in the southeastern US and the west coast, and similar problems elsewhere.
All of the above makes sense, but it's not just a theory; the evidence for such issues being real causes is in the patterns of which varieties of particular plants were domesticated where - and there is ample evidence that most of the crops in Eurasia were domesticated once, while those elsewhere were often domesticated two or more times
This was a fairly straightforward chapter, so, to start discussion, here's a poll: What's your favorite climate? Measuring climate is hard, but one classification is here