Solar cycle little changed in 290 million years

There's an interesting article in this week's (Jan. 21 -27, 2017) of The Economist relating to a study in Chemnitz, Germany. Scientists studying ancient tree rings there have found conclusive evidence that the solar cycle has essentially been the same since the Permian period. Read the article online here: http://www.economist.com/news/scien…tle-different-then-what-it-now-ancient-forest
Source: QRZ News
Link: Solar cycle little changed in 290 million years