Sir Francis Galton - Father of Eugenics, cousin of Darwin decided to experiment on twins just as Nazi Joseph Mengele experimented on three thousand sets of twins at Auschwitz-Birkenau. We can safely say that Joseph Mengele was just following and continuing the work of his fellow brother and father of Eugenics - Sir Francis Galton.
It is interesting to note that Sir Francis Galton was a Freemason. Here's the proof:
Francis Galton was initiated into Freemasonry on February 5, 1844, into the Scientific Lodge No. 105 of the Ancient, Free and Accepted Masons, held at the Red Lion Hotel, Cambridge, and on March 12, 1845, he was registered on the books of the Grand Lodge, London.
"Darwin's grandfather Erasmus Darwin himself was initiated at the St David's Lodge No 36, Edinburgh in 1754 at a time when Edinburgh was a center for enlightenment and medical knowledge. He was also a member of the Canongate Kilwinning Lodge No 2."
Charles Darwin obviously embellished grandfather Erasmus Darwin's book 'Zoonomia' when he wrote his infamous book of eugenics: "On the Origin of Species by Means of Natural Selection, or the Preservation of Favoured Races in the Struggle for Life."
As we can see the Darwins where busy at work, first in the Masonic lodge laying the foundations for the 'theory of evolution'
That's a fact!
It is also possible that Charles Darwin was a freemason, as suggested by the freemasons themselves!
As requested, here is T.H. Huxley confirming that he is a freemason in his own writings!!!