One caveat. The first trilobite fossils show up around 521 MYA. Right around the time at which Dr. Smith reconstructed the divergence of Panarthropoda and stem-Onychophora. Yet trilobites are not basal arthropods, but seem to be nested quite high up among the crown arthropoda.. which would suggest a much deeper shared common ancestor of each of the nodes outlined at the end than reconstructed here...
Thanks for this; I subscribed and will watch for more. Might I perhaps exist that you let us see the speaker rather than having him in the dark and have a blank background. Those of us who have difficulties concentrating find this sort of thing, with people walking around in the background a disturbance. I had to listen but not watch.
45:00 - considering the "speed" of Cambrian radiation, 20 million years - points out mammal radiation after KT boundary occurred in some 5 million years. Dr. Martin has a wonderful way with words! Great talk. "Simple as Sally" - Hurdia 'teeth' within the throat that ... "Shepherd it (prey) gently towards the digestive track" 25:10
I agree :-) An excellent, well constructed, and thought though, presentation that combined a number of potentially confusing issues in a clear fashion, with a well crafted conclusion. Many thanks.
Has there been any genetic studies on those foregut "teeth"? Seems like it would be a slamdunk for arthropod evolution if velvet worms and cockroaches had the same genes behind them.
It's been a while since I watched such interesting lecture. Thank you :-) I must say - I feel a little bit validated. I once compared Cambrian "explosion" to mammalian radiation while arguing with some creationist. And I came with this comparison all by myself ;-)
For the most part, we academics would refer to these organisms by their scientific name 'Priapulida' (or 'priapulids'). This scientific name is rooted in the early 1800s and honours the Greek god Priapus, who amongst things represents fertility and male genitalia. The common name Dr Smith used is a reflection of that resemblance. Both the scientific and common names are used legitimately; it's (unfortunately) just what they are called, what they've always been called, and we have no other name for them. Organisms will often have names that help communicate what they look like and there are numerous other examples of plants, animals and fungi being named for their resemblance to genitals. Such names are useful in science and aren't intended to be or used as a joke. I'm sorry it's caused you offence.
@googleuser3163 Of all the videos on TH-cam you report an academic presentation 😂 Please educate yourself on academic terminology in biology, psychiatry, medicine, veterinary. Penis a body part not an offensive word genius.
You show a coelacanth fossil that's 80 million years old then you talk about how it turned into a human got up and walked but then we're pulling actual coelacanths out of the ocean unchanged I think this puts the nail in the coffin.
Anthony Maldonado Coelacanth is not a species of fish. Coelacanth is a order of fish with 20 genera and over 80 species, all but two extinct. The two extant( still around) species are morphologically different from the 78+ extinct species fossils have not been found going back more than a few million years. Look it up. BUT....Even if what you state were true( and it is no where near true, as you, like most people mistake Coelacanth for a species of fish) then it would in no way be a nail in any coffin. Just because one, or even a few, species fail to appreciably evolve, in no way means that the overwhelming majority of life does not. That is like looking at a picture of Dick Clark from 1980, then one from 200, noting how the man did not really appear to age in a twenty year period, then stating that that proves that human beings do not usually visibly age over a twenty year period, ignoring the mountains of evidence that they indeed do, because of one anomaly. Also, "turned into" is not a evolutionary concept, and evolution theory does not go on that a species of Coelacanth evolved into land animals.
"Just because one, or even a few, species fail to appreciably evolve, in no way means that the overwhelming majority of life does not." Just to clarify on this point: current evolutionary theory does NOT say, "All living things must change with time"...what it says is, "A species may change in response to a change in environmental/ecological pressure" on that species. There have been many species shown to vary little if at all after millions of years...why? Is it because there's no such thing as evolution? NO. Because the environmental/ecological niche that that species occupied varied almost not at all in that time. There was never any spur to change. Random mutations are still likely to occur all of the time, but if the mutation confers no survival/reproductive advantage to the individual (or their descendants), then that mutation will not appear as the majority in the entire gene pool. Some make the mistake of thinking of evolution as a process where the species is always "getting better," "becoming more sophisticated," and/or "increasing in complexity." But none of these are the case. Evolution simply means that as the ecological environment changes (if it does), only those genetic lines that have the genetic mutation(s) that confer some survival/reproductive advantage will eventually dominate the population. And interestingly, if the advantage is one results in a DECREASE in "complexity or sophistication," Nature will still deem that genetic line better (but only for the moment). I think the idea that something more complex and "sophisticated" than a bacterium (e.g. a human) is therefore axiomatically some kind of acme of evolution is a pathetically anthropocentric viewpoint. Humans like to see themselves as better than all other species, it's our bias. Just to keep using bacteria as an example, their various species have been FAR more "successful" than humans not only in their longevity on this planet [billions of years on this planet versus our few millions of years, and despite cataclysmic upheavals such as asteroid impacts, vulcanism, etc... ], but also the sheer variety of the ecological niches that they occupy, their sheer biomass on the planet compared to ours, the fact that they FAR outnumber our mammalian cells, and that they can evolve in hours to survive environmental changes that would off humanity in a second. And yet their success doesn't even depend on possesing a brain, or even just a nerve network. They are a relatively "simple," "unsophisticated" life form that kicks butt. Peace.
Why did the coelacanth not evolve its still the same now or the crocodiles same now or frogs. Blah blah same old stuff that doesn't really explain origins.
Coelacanth is different from the known fossils of Coelacanthiformes. Modern crocodiles are by far different from the earliest Crocodylomorpha. Modern frogs are different from fossil frogs like Triadobatrachus. If you think in evolution, you must think in branches: evolution takes several directions simultaneously, including to maintain a similar morphology and explore new morphologies, at the same time in the same group.
![[LIVE] : ONE ลุมพินี 91 | คู่เอก "คมอาวุธ vs อเล็กเซย์"](http://i.ytimg.com/vi/V0RkEfYFsgM/mqdefault.jpg)
This is extremely insightful work and a great presentation!
this is my favorite kind of lecture and I loved ever minute of it.
Strangely, cat claws also work that way - they pop off intact, leaving a smaller functional claw below that continues to grow till it too is shed.
I think the point was that Onychophoran claws *don't* pop off, making this a unique trait.
One caveat. The first trilobite fossils show up around 521 MYA. Right around the time at which Dr. Smith reconstructed the divergence of Panarthropoda and stem-Onychophora. Yet trilobites are not basal arthropods, but seem to be nested quite high up among the crown arthropoda.. which would suggest a much deeper shared common ancestor of each of the nodes outlined at the end than reconstructed here...
Rusophycus which is a trace fossil by a euarthropod generally, if not a crown euarthropod, go as far as 537 mya
my point exactly - the divergence of panarthropoda must be significantly older than indicated here. @@DenverSuyom
Thanks for this; I subscribed and will watch for more. Might I perhaps exist that you let us see the speaker rather than having him in the dark and have a blank background. Those of us who have difficulties concentrating find this sort of thing, with people walking around in the background a disturbance. I had to listen but not watch.
Great presentation. thanks for uploading this.
We have hundreds of other videos from lots of different conferences. They're all arranged into playlists on our TH-cam channel.
I plan to do some exploring in those!
This video makes me so happy. I've always been interested in velvet worms and theres so little easily accessible info about them :)
Very interesting. Thanks for sharing.
This is excellent thanks for posting
45:00 - considering the "speed" of Cambrian radiation, 20 million years - points out mammal radiation after KT boundary occurred in some 5 million years.
Dr. Martin has a wonderful way with words! Great talk.
"Simple as Sally" - Hurdia 'teeth' within the throat that ... "Shepherd it (prey) gently towards the digestive track" 25:10
Wow and it makes so much more sense. Excellent presentation!
I agree :-)
An excellent, well constructed, and thought though, presentation that combined a number of potentially confusing issues in a clear fashion, with a well crafted conclusion. Many thanks.
Has there been any genetic studies on those foregut "teeth"? Seems like it would be a slamdunk for arthropod evolution if velvet worms and cockroaches had the same genes behind them.
Thanks. Incredibly insightful!
It's been a while since I watched such interesting lecture. Thank you :-)
I must say - I feel a little bit validated. I once compared Cambrian "explosion" to mammalian radiation while arguing with some creationist. And I came with this comparison all by myself ;-)
@@arekwittbrodt Glad you enjoyed it! We'll be releasing a brand new Cambrian Explosion lecture series soon!
Excellent talk, but the visuals are almost useless because of the lighting.
Love this thank you
6:40 tatakae...if you dont fight you cant win
Great presenter but would suggest zooming in on the screen and not in front of windows.
It just keeps moving forward
Noooooo
I didn't think i find you here
I think Hallucigenia was the echinoderm version of worms...
Reported for the joke about "pen!$" worms. Disgraceful behavior, disgusting body parts like that should not be mentioned EVER in academic settings.
For the most part, we academics would refer to these organisms by their scientific name 'Priapulida' (or 'priapulids'). This scientific name is rooted in the early 1800s and honours the Greek god Priapus, who amongst things represents fertility and male genitalia. The common name Dr Smith used is a reflection of that resemblance. Both the scientific and common names are used legitimately; it's (unfortunately) just what they are called, what they've always been called, and we have no other name for them.
Organisms will often have names that help communicate what they look like and there are numerous other examples of plants, animals and fungi being named for their resemblance to genitals. Such names are useful in science and aren't intended to be or used as a joke. I'm sorry it's caused you offence.
@googleuser3163 Of all the videos on TH-cam you report an academic presentation 😂 Please educate yourself on academic terminology in biology, psychiatry, medicine, veterinary. Penis a body part not an offensive word genius.
Not the best enounciation. I find my self missing huge chunks of express train monologue.
You show a coelacanth fossil that's 80 million years old then you talk about how it turned into a human got up and walked but then we're pulling actual coelacanths out of the ocean unchanged I think this puts the nail in the coffin.
Why would the be? Can you explain?
Are you in essence asking, "If Americans descended from Europeans, why are there still Europeans...?"
Anthony Maldonado
Coelacanth is not a species of fish. Coelacanth is a order of fish with 20 genera and over 80 species, all but two extinct. The two extant( still around) species are morphologically different from the 78+ extinct species fossils have not been found going back more than a few million years. Look it up.
BUT....Even if what you state were true( and it is no where near true, as you, like most people mistake Coelacanth for a species of fish) then it would in no way be a nail in any coffin. Just because one, or even a few, species fail to appreciably evolve, in no way means that the overwhelming majority of life does not. That is like looking at a picture of Dick Clark from 1980, then one from 200, noting how the man did not really appear to age in a twenty year period, then stating that that proves that human beings do not usually visibly age over a twenty year period, ignoring the mountains of evidence that they indeed do, because of one anomaly.
Also, "turned into" is not a evolutionary concept, and evolution theory does not go on that a species of Coelacanth evolved into land animals.
Dave, I suspect Anthony couldn't care less. But I appreciate you taking the time to jot down that interesting explanation. Thank you
"Just because one, or even a few, species fail to appreciably evolve, in no way means that the overwhelming majority of life does not."
Just to clarify on this point: current evolutionary theory does NOT say, "All living things must change with time"...what it says is, "A species may change in response to a change in environmental/ecological pressure" on that species. There have been many species shown to vary little if at all after millions of years...why? Is it because there's no such thing as evolution? NO. Because the environmental/ecological niche that that species occupied varied almost not at all in that time. There was never any spur to change. Random mutations are still likely to occur all of the time, but if the mutation confers no survival/reproductive advantage to the individual (or their descendants), then that mutation will not appear as the majority in the entire gene pool.
Some make the mistake of thinking of evolution as a process where the species is always "getting better," "becoming more sophisticated," and/or "increasing in complexity." But none of these are the case. Evolution simply means that as the ecological environment changes (if it does), only those genetic lines that have the genetic mutation(s) that confer some survival/reproductive advantage will eventually dominate the population. And interestingly, if the advantage is one results in a DECREASE in "complexity or sophistication," Nature will still deem that genetic line better (but only for the moment).
I think the idea that something more complex and "sophisticated" than a bacterium (e.g. a human) is therefore axiomatically some kind of acme of evolution is a pathetically anthropocentric viewpoint. Humans like to see themselves as better than all other species, it's our bias. Just to keep using bacteria as an example, their various species have been FAR more "successful" than humans not only in their longevity on this planet [billions of years on this planet versus our few millions of years, and despite cataclysmic upheavals such as asteroid impacts, vulcanism, etc... ], but also the sheer variety of the ecological niches that they occupy, their sheer biomass on the planet compared to ours, the fact that they FAR outnumber our mammalian cells, and that they can evolve in hours to survive environmental changes that would off humanity in a second. And yet their success doesn't even depend on possesing a brain, or even just a nerve network. They are a relatively "simple," "unsophisticated" life form that kicks butt. Peace.
Why did the coelacanth not evolve its still the same now or the crocodiles same now or frogs.
Blah blah same old stuff that doesn't really explain origins.
Coelacanth is different from the known fossils of Coelacanthiformes. Modern crocodiles are by far different from the earliest Crocodylomorpha. Modern frogs are different from fossil frogs like Triadobatrachus. If you think in evolution, you must think in branches: evolution takes several directions simultaneously, including to maintain a similar morphology and explore new morphologies, at the same time in the same group.
Evolutionary change is the exception, not the rule.