From Gerd Bossinger and Antanas Spokevicius at Phys.org:
From ancient European beech trees to gigantic Californian redwoods and Australian mountain ashes, new research has found the enormous trunks of these trees are all formed from a single layer of cells no wider than the tip of a needle.
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Wood is one of the world’s most important renewable resources, so you’d think we’d have an understanding of how it grows. But until now we didn’t know exactly how cells within the vascular cambium go about their business. The number of cell layers that make up the vascular cambium, and to what degree the fate of individual cells within the cambium is predetermined, has been a matter of debate for over a century.
Some cells in the vascular cambium are stem cells, meaning they are yet to differentiate into their final form. Each cell could go on to form wood or bark, or possibly something else. To avoid confusion with the other definition of stem – a branch – we call these vascular cambium stem cells ‘initiating cells’ or ‘initials’.
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There are many opportunities to use these new insights for commercial gain but fundamentally our findings add to our understanding of what makes a tree tick. It is amazing to think that the enormous trunks of ancient beeches, giant redwoods and towering mountain ash all form from a single layer of cells no wider than the tip of a needle. More.
One wonders whether part of the reason it took over a century to find out was the sense that it would be something simple, something that could just somehow randomly evolve…
See also: From The Scientist: How first and “very, very complex” trees got to be so big 420 million to 359 mya
and
Researchers: Earth’s first trees were also “most complex” How did we know Darwinism was true? Because the first plants were simplest, right? So would a Darwinian account of life have predicted this? Does it predict anything? Is there anything about it that is actually true in a science-based way?