00:01The largest single step in the ascent of man is the change from nomad to village
00:07agriculture. What made that possible? An act of will by men, surely, but with that
00:15a strange and secret act of nature. At the end of the Ice Age a hybrid wheat
00:22appeared in the Middle East. It happened in many places. A typical one is the
00:27ancient oasis of Jericho. Jericho is older than agriculture. The first people that
00:35came here and settled by the spring in this otherwise desolate foreground were
00:42people who harvested wheat but did not yet know how to plant it. That's an
00:48extraordinary piece of foresight. They made sickles which have survived out of
00:54flint. Garstang found these when he was digging here in the 1930s. The holders in
00:59which these were fitted have been found and so I've reconstructed the kind of
01:05sickle with which they went out and found the wild wheat and harvested it. Here it
01:12is, the ancient sickle edges set in a modern piece of gazelle horn of the kind
01:20that they used or they used bone.
01:26There no longer survives up here on the tell the kind of wild wheat that they harvested but
01:34the grasses that are still here must look very like the wheat that they found. That they
01:40gathered for the first time by the fistful and cut with that soaring motion of the sickle
01:47that reapers have used for all the 10,000 years since then. That was the Natafian
01:55pre-agricultural civilization and of course it couldn't last. It was on the brink of becoming
02:01agriculture and that's the next thing that happened here on the Jericho Hotel.
02:13The turning point to the spread of agriculture in the old world was almost certainly the occurrence
02:19of two forms of wheat with a large full head of seeds. Before 8,000 BC wheat was not the
02:26luxuriant plant it is today. It was merely one of many wild grasses that spread throughout the
02:32Middle East. The time lapse film shows six weeks of growth of a primitive wild wheat of this
02:38kind. By some genetic accident the wild wheat crossed with a natural goat grass and formed
02:47a fertile hybrid. That accident must have happened many times in the springing vegetation that
02:53came up after the last ice age. In terms of the genetic machinery that directs growth it combined the 14
03:08chromosomes of wild wheat with the 14 chromosomes of goat grass and produced emma with 28 chromosomes.
03:16That's what makes emma so much plumper. The hybrid was able to spread naturally because its seeds are
03:23attached to the husk in such a way that they scatter in the wind. For such a hybrid to be
03:31fertile
03:31is rare but not unique among plants. But now the story of the rich plant life that followed the ice
03:38age
03:38becomes more surprising. There was a second genetic accident which may have come about because emma was
03:47already cultivated. Emma crossed with another natural goat grass and produced a still larger hybrid with 42 chromosomes
03:57which is bread wheat. That was improbable enough in itself and we know now that bread wheat would not have
04:05been fertile but for a specific genetic mutation on one chromosome. Yet there is something even stranger.
04:17Now we have a beautiful ear of wheat but one which will never spread in the wind because the ear
04:23is too
04:24too tight to break up and if I do break it up why then the chaff flies off and every
04:31grain falls exactly where it grew.
04:35Let me just remind you that's quite different from the primitive weeds like emma.
04:39You see the ear is much more open and if this ear breaks up then you get quite a different
04:45effect.
04:49You get grains which will fly in the wind. The bread wheats have lost that ability. Suddenly man and the
04:58plant
04:58have come together. Man has a wheat that he lives by but the wheat also thinks that man was made
05:06for him
05:06because only so can it be propagated.
