Benjamin, please lend me advice here if you've the time. I'm just a dabbler; you LIVE paleobiology. 1) Does "Cooksonia" represent a huge paraphyletic experiment in early tracheophyte-dom? 2) I'm eagerly anticipating refinements in molecular phylogeny to finally understand the conquest of the land. What's your take: is there a liverwort/moss sister group to the rest of the land plants? Is there a possible hornwort/lycopod clade that could be viewed as the sister to the rest of the tracheophytes? 3) What about those pesky nematophytes from the Cambrian? Are a lot of nematophytes just resistant parts of liverworts? 4) Do Cambrian and Ordovician paleosols show any evidence for plant involvement in their formation? I first started thinking about 1) & 2) after going through my (now ancient) textbook, "Cryptogamic Botany" more than half a century ago. Glad to be alive to see all this progress. Again, my sincerest thanks. Your video series is an heroic work-in-progress to comprehensively fill a chasm.
1) Most likely! 2) I really don't know, there are some really detailed molecular phylogeny papers out there on living plants. Have to do some searching in the literature. 3) Maybe, there is a growing number of them being found, and some of this Cambrian fossils are looking really interesting in terms of plant evolution. 4) Not much that I've seen. Roots appear to develop in the Silurian, but don't make much of an impact until the Devonian. I recently read a paper, forgot where, about some Silurian paleosols.
Benjamin Burger This delayed or slow motion adaptive radiation from fresh water on to the land has troubled me for ages. Naïvely, it would now seem that the molecular preadaptations in the Charophytes and subsequent (surmised) Cambrian Marchantiophytes were more than sufficient to facilitate a mid to late "Cambrian Explosion" of terrestrial life - at least in freshwater & slightly brackish swamps and swamp margins. What could be the missing impediments to this? There must have been very serious hidden problems to overcome. What might they be?
1. cooksonia probably isn’t paraphyletic, but just very common because of preservation bias due to its ecology. it isn’t ancestral to bryophytes and it’s relation to vascular plants is unclear. 2. lycophytes are more closely related to the other extant vascular plants. hornworts moss and liverworts are also more closely related to each other than to the vascular plants. 3. They are definitely not liverworts. Maybe they’re ancestral to all land plants, but liverworts as a group is monophyletic so that’s out of the question. 4. early vascular plants didn’t have roots, they had rhizoids similar to extant non-vascular plants. Roots evolved separately in multiple groups around the start of the devonian.
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Benjamin, please lend me advice here if you've the time. I'm just a dabbler; you LIVE paleobiology.
1) Does "Cooksonia" represent a huge paraphyletic experiment in early tracheophyte-dom?
2) I'm eagerly anticipating refinements in molecular phylogeny to finally understand the conquest of the land. What's your take: is there a liverwort/moss sister group to the rest of the land plants? Is there a possible hornwort/lycopod clade that could be viewed as the sister to the rest of the tracheophytes?
3) What about those pesky nematophytes from the Cambrian? Are a lot of nematophytes just resistant parts of liverworts?
4) Do Cambrian and Ordovician paleosols show any evidence for plant involvement in their formation?
I first started thinking about 1) & 2) after going through my (now ancient) textbook, "Cryptogamic Botany" more than half a century ago. Glad to be alive to see all this progress.
Again, my sincerest thanks. Your video series is an heroic work-in-progress to comprehensively fill a chasm.
1) Most likely!
2) I really don't know, there are some really detailed molecular phylogeny papers out there on living plants. Have to do some searching in the literature.
3) Maybe, there is a growing number of them being found, and some of this Cambrian fossils are looking really interesting in terms of plant evolution.
4) Not much that I've seen. Roots appear to develop in the Silurian, but don't make much of an impact until the Devonian. I recently read a paper, forgot where, about some Silurian paleosols.
Benjamin Burger This delayed or slow motion adaptive radiation from fresh water on to the land has troubled me for ages. Naïvely, it would now seem that the molecular preadaptations in the Charophytes and subsequent (surmised) Cambrian Marchantiophytes were more than sufficient to facilitate a mid to late "Cambrian Explosion" of terrestrial life - at least in freshwater & slightly brackish swamps and swamp margins. What could be the missing impediments to this? There must have been very serious hidden problems to overcome. What might they be?
1. cooksonia probably isn’t paraphyletic, but just very common because of preservation bias due to its ecology. it isn’t ancestral to bryophytes and it’s relation to vascular plants is unclear.
2. lycophytes are more closely related to the other extant vascular plants. hornworts moss and liverworts are also more closely related to each other than to the vascular plants.
3. They are definitely not liverworts. Maybe they’re ancestral to all land plants, but liverworts as a group is monophyletic so that’s out of the question.
4. early vascular plants didn’t have roots, they had rhizoids similar to extant non-vascular plants. Roots evolved separately in multiple groups around the start of the devonian.
Love it! I would like a longer videos that you make. You can practice pronunciation of the lifeforms more by doing longer videos!
A well done video. Thanks!
bara-gwana-thia. Easier to say when you break it up like that.
Coool!