The Lancelet's Tale

A discussion of “The Lancelet’s Tale” in Richard Dawkins’ and Yan Wong’s book The Ancestor’s Tale.
“An ancestral axial twist explains the contralateral forebrain and the optic chiasm in vertebrates”

[LanceHall]

It's amazing the degree to which various organs can mapped to ancestral parts that may or may not serve a similar function.

[Shipfish]

i badly need an episode explaining the thing at about 37:40 about the turning of the head... it's freaking me out, i need to know more

[hulick]

These creatures are, surprisingly, less closely related to vertebrates than tunicates are to vertebrates. Tunicates and vertebrates are in the clade Olfactores, characterized by a pharynx and a complex sense of smell as well as well defined sensory organs. Both tunicates and vertebrates have a pharynx and defined sensory organs, though baby tunicates, called tadpoles, have eyes and a central nervous system but digest it alongside their notochord and tail when they metamorphose into adults. It is also notable that some tunicates, like salps, maintain their eyes in their adult stage because they swim around.

[noeditbookreviews]

Whoa. I never knew about this channel! Dawkins in my favorite author.

[whyukraine]

Please put a description link to the collaborative Cambrian video you mentioned at the beginning.

[jamesdownard]

That Janvier 2015 quote fits neatly into a spot in Ch 5 of Vol 2 Rocks :)

[nebulan]

There are two modern living organisms that are MY direct ancestors. And my siblings'.

[brianjacob]

my parents are my direct ancestors. they are organisms.

[wcdeich]

Are sessile tunicates more closely related to vertebrates than the other tunicates?

[longcastle]

So does stem, as in stem vertebrates, refer to extinct animals that nevertheless still have living descendants today? So that “stem” refers to the original branch from which other similar species branched off of? Unfortunately a quick google search doesn’t quite make it clear.