Southerly by David Haywood

Hi David,
I've come to this series a little late but I want to say it's been brilliant so far. I won't even begin to guess the energy expended in putting the series together. The thesis that human civilisational development takes a leap forward when a new energy source is an interesting view. I'd buy that. Seems obvious really. It does beg the question as to what the next quantum leap may be and if we find it in time for humankind's looming energy deficit. I'm hoping to see something out of the realms of science fiction in my lifetime. There's a fusion reactor being constructed in France but we won't know for years if the technology will be successful. It will be interesting to hear your conclusions as the series progresses.

Hi David

ooo now this is fun stuff. You are of course getting into chicken and egg discussions about which came first. I think you are probably right but possibly skipping over the issue that several factors have to combine before significant changes occur. Fire was definately critical but other factors were important too.

The problem with figuring out the critical event is that the changes in hominid life occurred over such a large timescale that changes that occurred thousands of years apart look like simultaneous events to us. I think one factor in development that you're skipping is the development of memory and language. It's one thing to have fire available but it's another to be able to communicate from generation to generation the methods of handling required and the importance of fire.

However, the link between Fire and Agriculture is rock solid. I'll add one other food we don't think about in the western world much. Casava is the third biggest source of carbohydrate int he world and particularly important in Africa (although it originated in Sth America). What's interesting is the root is very toxic, containing cyanogenic glucosides which get converted to cyanide when the cells are broken. However it is an incredibly productive crop second only to sugarcane. To get rid of the cyanogenic compounds the roots need to be cooked, often for several days. So without fire, this rich food source would not be available.

But again it isn't just the presence of Fire that is important, it's the ability to remember that cooked Casava didn't kill grandpa and the ability to communicate that knowledge.

Even your early hominids with league player jaws had to have enough language and memory to know that cooked meat tasted better and was easier to eat before they could lose their er "manly" jawbones.

cheers
Bart

Bart Janssen wrote:

You are of course getting into chicken and egg discussions about which came first... I think you are probably right but possibly skipping over the issue that several factors have to combine before significant changes occur... I think one factor in development that you're skipping is the development of memory and language. It's one thing to have fire available but it's another to be able to communicate from generation to generation the methods of handling required and the importance of fire.

An interesting argument (as always), Bart.

I was taking hominids with memory (as per other large animals) as a starting point. I'm not actually sure that language was necessary for the use of fire. For example, I understand that there is debate about what degree of language fire-using Homo erectus possessed. One can certainly envisage the use and importance of fire being passed from one generation to the next by imitation rather than spoken language. It's fascinating to speculate whether language led to fire, or fire (through the evolutionary de-emphasis of those league-player skulls) led to language. That would be your chicken-and-egg argument, I guess.

The application of energy released by the burning of plant biomass is, by definition, tool use -- so rudimentary tool use is obviously a critical element in the harnessing of fire -- but beyond that it's difficult to see what would have been possible without fire. It's hard to imagine that Homo sapiens could have spread out of the tropical regions if they didn't have the ability to use fire.

You make a good point about several factors combining to enact significant change. For example, the development of agriculture requires suitable crops and/or animals for domestication; the development of metals requires the right sort of ore to be locally available. But in terms of the human side of the equation (i.e. what humans had to do to exploit the available resources) it's hard to imagine any subsequent important technological development being possible without the 'chain reaction' of energy from fire (and/or one of the other non-food energy sources). The only exception that springs to mind is the ability to 'store' language through writing -- although, in practise, this followed rather than preceded agriculture (which, as you point out, depended on fire -- in fact, it 's been argued that writing first originated from agricultural commerce).

Very interesting about Cassava... I had no idea it was quite so toxic in its raw form. By any chance do you know how it moved from South America to Africa -- another trade good of those cunning Polynesians?

At any rate, I'll be expanding upon the importance-of-energy theme in subsequent episodes...

Charles Mabbett wrote:

I've come to this series a little late but I want to say it's been brilliant so far... The thesis that human civilisational development takes a leap forward when a new energy source is an interesting view. I'd buy that. Seems obvious really.

Glad that it makes sense so far, Charles... (and you're not too late -- still another ten episodes to go!)

It seems obvious to me too, but my historian friends would certainly argue that energy is only one of several important elements (I agree, but would argue that it's the one essential element, of course).

And my economist friends maintain that our current energy sources are no different from mineral resources like copper, etc. They certainly see economic growth as a cause of additional energy usage -- not a consequence.

I'm curious about what that long delay between the use of fire and the knowledge of how to make fire possibly says about our early ancestors' view of the world around them.

We clever Homo sapiens now know all about fire - how it's a product of chemical reactions. But we didn't know that until fairly recently - a couple of hundred years ago. Prior to that it was thought to be an element in itself.

So go back to those early years on the savannah, where hominids had even less intellectual capacity than us. Lightening strikes a tree and fire is produced. What would that appear like to those observing? Perhaps a bit like the hand of God touching the earth and producing magic. (Not that this is exactly what they might have imagined but the general idea that fire was a fire strange phenomena).

It would have taken a while to recognise that fire was not just a gift from heaven but the product of heat and therefore something that humans could produce. It would require a leap to a quite different understanding of the physical world much like the leap from phlogiston to energy.

**REPLY:** an interesting point, Neil. I've wondered a lot about that delay as well. Cheers, DH

Regarding Cassava
Some quick reading makes me an expert in its origins (not) but as far as I can tell from my reading Cassava (__Manihot esculenta__) as we know it now is very much domesticated and probably the result of some hybridisation (crosses between different wild species) and introgression (fancy genetic term meaning traits/genes from one species get bred into another species). All of which makes figuring out the wild progenitor difficult. But the best guess seems to be some derivative of Manihot flabellifolia which has its range in Brazil, Paraguay, Uruguay and Argentina.

Domestication appears to have been started 5000-7000 BC in the Amazon basin. As for how the Africans got Cassava well that seems to have been the Portuguese in the 17th century rather than the Polynesians and the Spanish took it to Asia.

Neil wrote about how the hominids viewed Fire. I guess my concern is that it’s really hard to figure out what those hominids were thinking. We all know that different cultures can view quite simple things from completely different perspectives. A local example is the inability of most Europeans to “get” the Maori idea of “family”. For the Maori it’s a very simple and obvious concept and yet it is completely non-obvious to the Europeans (whad’ya mean that hill is a relative???). Similarly we look at Fire and try and imagine what it must have been to the early hominids – but we do it from a completely different cultural perspective. My gut feeling is that the hominids probably didn’t have any concept of god or magic or even the concept that Fire was “strange” in any way. It simply was part of the environment, like a rock or a river, dangerous in some circumstances useful in others. I suspect that any attempt by us to put ourselves in their heads is doomed to failure, our cultural perspective makes it impossible.

BTW don’t get too high and mighty about our intellectual capacity, we actually have smaller brains than some of our hominid brethren. It really is very difficult to know what intellectual ability was achievable by those hominids. It’s quite possible that some of those hominids were quite smart. The interesting thing about the last half a million years or so is that most of the development of humans has been about cultural change rather than biological change. It’s quite possible that those hominids were as smart or smarter than a 10 year old – they just had no knowledge base to work from.

I guess my concern is that it’s really hard to figure out what those hominids were thinking....I suspect that any attempt by us to put ourselves in their heads is doomed to failure, our cultural perspective makes it impossible.

It's very difficult to figure out what they were thinking but it's not necessarily doomed to failure. There is evidence that can be interpreted (although perhaps not definitively in all cases), such as the length of time between using fire and creating fire. The development of representational art, tool use, funeral practices etc - each must imply a change in the way our primate ancestors understood and interacted with the world and each other and hence can be evidence of changes within our brain/mind.

Thanks for doing this, I finally caught up with the first two, and it got me so interested in the area I started watching The Ascent of Man again...

**REPLY:** Very glad you're enjoying it, Graeme -- thanks for letting me know. Cheers, DH

Might I also suggest reading this fellow, http://en.wikipedia.org/wiki/Erich_Neumann_(psychologist).