Season 4 Episode 6: Your Inner Sea Squirt

Mark, Sarah, and James discuss Chapter 6 of Charles Darwin's Descent of Man. In this chapter Darwin unequivocally declares humans evolved from ancestral primate stock and that event occurred in Africa. We discussed how prescient Darwin was in interpreting the biology and scant fossil record in determining human relationship in the evolutionary tree. 

(Image credit: Nick Hobgood/Wikimedia Commons)

We discussed at length this problematic paragraph:

The great break in the organic chain between man and his nearest allies, which cannot be bridged over by any extinct or living species, has often been advanced as a grave objection to the belief that man is descended from some lower form; but this objection will not appear of much weight to those who, convinced by general reasons, believe in the general principle of evolution. Breaks incessantly occur in all parts of the series, some being wide, sharp and defined, others less so in various degrees; as between the orang and its nearest allies—between the Tarsius and the other Lemuridæ—between the elephant and in a more striking manner between the Ornithorhynchus or Echidna, and other mammals. But all these breaks depend merely on the number of related forms which have become extinct. At some future period, not very distant as measured by centuries, the civilised races of man will almost certainly exterminate and replace throughout the world the savage races. At the same time the anthropomorphous apes, as Professor Schaaffhausen has remarked, will no doubt be exterminated. The break will then be rendered wider, for it will intervene between man in a more civilised state, as we may hope, than the Caucasian, and some ape as low as a baboon, instead of as at present between the negro or Australian and the gorilla.

After that awkward discussion we finished with the notion that our ancestor probably looked like a sea squirt. 

Here is the episode that Sarah referenced on the economics of Darwin's voyage - it was called to Drawn a Bill

The opening and closing theme to Discovering Darwin is "May" by Jared C. Balogh.

1st interlude music was Mr. Smith - Happy Dance.

https://freemusicarchive.org/music/mr-smith

2nd Interlude music

It's a long way to Amphioxus by Sam Hinton https://www.youtube.com/watch?v=B0egWbwErRQ