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The remarkable fossil record of whales and dolphins (Cetacea) has made them an exemplar of macroevolution. Although their overall adaptive transition from terrestrial to fully aquatic organisms is well known, this is not true for the radiation of modern whales. Here, we explore the diversification of extant cetaceans by constructing a robust molecular phylogeny that includes 87 of 89 extant species. The phylogeny and divergence times are derived from nuclear and mitochondrial markers, calibrated with fossils. We find that the toothed whales are monophyletic, suggesting that echolocation evolved only once early in that lineage some 36–34 Ma. The rorqual family (Balaenopteridae) is restored with the exclusion of the gray whale, suggesting that gulp feeding evolved 18–16 Ma. Delphinida, comprising all living dolphins and porpoises other than the Ganges/Indus dolphins, originated about 26 Ma; it contains the taxonomically rich delphinids, which began diversifying less than 11 Ma. We tested 2 hypothesized drivers of the extant cetacean radiation by assessing the tempo of lineage accumulation through time. We find no support for a rapid burst of speciation early in the history of extant whales, contrasting with expectations of an adaptive radiation model. However, we do find support for increased diversification rates during periods of pronounced physical restructuring of the oceans. The results imply that paleogeographic and paleoceanographic changes, such as closure of major seaways, have influenced the dynamics of radiation in extant cetaceans.
Partial skeletons of two new fossil whales, Artiocetus clavis and Rodhocetus balochistanensis, are among the oldest known protocetid archaeocetes. These came from early Lutetian age (47 million years ago) strata in eastern Balochistan Province, Pakistan. Both have an astragalus and cuboid in the ankle with characteristics diagnostic of artiodactyls; R. balochistanensis has virtually complete fore- and hind limbs. The new skeletons are important in augmenting the diversity of early Protocetidae, clarifying that Cetacea evolved from early Artiodactyla rather than Mesonychia and showing how early protocetids swam.
Georgiacetus vogtlensis is one of the most primitive archaeocetes (ancient whales) from North America. Discovered in the northern Atlantic Coastal Plain of Georgia in 1983, it has been interpreted as semi-aquatic, but shows important adaptions toward fully aquatic behavior, including the lack of articulation between the pelvis and sacral vertebrae. Among all protocetids, Georgiacetus is most closely related to the clade Pelagiceti, which includes the common ancestor of all fully aquatic archaeocetes and their descendants, including modern whales. The goal of this study is to elucidate aspects of Georgiacetus locomotion and behavior that are closely related to both semi-aquatic and aquatic lifestyles by comparing the skeletal morphology of the lumbar region of Georgiacetus to modern mammals of a known lifestyle. Unlike previous studies using muscle scarring, this investigation into those changes in skeletal morphology that occurred during the land-to-sea transition of whale evolution was achieved via multivariate analyses of 17 measurements of lumbar vertebrae from more than 30 modern and extinct mammals. Lumbar vertebrae were used because they likely underwent the most drastic changes during the early stages of whale evolution, as dorsomobile archaecetes evolved relatively quickly from dorsostable artiodactyls.
The last two decades have witnessed an explosive growth in the number of fossils documenting the origins of Cetacea (whales, dolphins, and porpoises). An excellent morphological series of transitional cetaceans is now available to document the transition from land to sea, and many sophisticated analyses detail the biology of these archaic cetaceans. The origin of whales now offers a spectacular example of evolutionary change, allowing us to chart changes in anatomy and physiology as whales first moved into the water and then gradually explored the open seas.
originally posted by: aorAki
a reply to: TinfoilTP
You see, the problem with that is that the source is from a creationist/intelligent design bent. The editors are Paul Brown and Robert Stackpole and you would be much better off investigating the work of Professor Ewan Fordyce who actively researches cetacean evolution. New Zealand is fortunate enough to have an excellent fossil record for cetaceans, particularly around Oamaru, and he also travels widely to 'offshore' fossil sites.
Radiation of Extant Cetaceans Driven by Restructuring of the Oceans
The remarkable fossil record of whales and dolphins (Cetacea) has made them an exemplar of macroevolution. Although their overall adaptive transition from terrestrial to fully aquatic organisms is well known, this is not true for the radiation of modern whales. Here, we explore the diversification of extant cetaceans by constructing a robust molecular phylogeny that includes 87 of 89 extant species. The phylogeny and divergence times are derived from nuclear and mitochondrial markers, calibrated with fossils. We find that the toothed whales are monophyletic, suggesting that echolocation evolved only once early in that lineage some 36–34 Ma. The rorqual family (Balaenopteridae) is restored with the exclusion of the gray whale, suggesting that gulp feeding evolved 18–16 Ma. Delphinida, comprising all living dolphins and porpoises other than the Ganges/Indus dolphins, originated about 26 Ma; it contains the taxonomically rich delphinids, which began diversifying less than 11 Ma. We tested 2 hypothesized drivers of the extant cetacean radiation by assessing the tempo of lineage accumulation through time. We find no support for a rapid burst of speciation early in the history of extant whales, contrasting with expectations of an adaptive radiation model. However, we do find support for increased diversification rates during periods of pronounced physical restructuring of the oceans. The results imply that paleogeographic and paleoceanographic changes, such as closure of major seaways, have influenced the dynamics of radiation in extant cetaceans.
There are also others researching this:
Origin of Whales from Early Artiodactyls: Hands and Feet of Eocene Protocetidae from Pakistan
Partial skeletons of two new fossil whales, Artiocetus clavis and Rodhocetus balochistanensis, are among the oldest known protocetid archaeocetes. These came from early Lutetian age (47 million years ago) strata in eastern Balochistan Province, Pakistan. Both have an astragalus and cuboid in the ankle with characteristics diagnostic of artiodactyls; R. balochistanensis has virtually complete fore- and hind limbs. The new skeletons are important in augmenting the diversity of early Protocetidae, clarifying that Cetacea evolved from early Artiodactyla rather than Mesonychia and showing how early protocetids swam.
Locomotion and Behavior of the Ancient Whale Georgiacetus
Georgiacetus vogtlensis is one of the most primitive archaeocetes (ancient whales) from North America. Discovered in the northern Atlantic Coastal Plain of Georgia in 1983, it has been interpreted as semi-aquatic, but shows important adaptions toward fully aquatic behavior, including the lack of articulation between the pelvis and sacral vertebrae. Among all protocetids, Georgiacetus is most closely related to the clade Pelagiceti, which includes the common ancestor of all fully aquatic archaeocetes and their descendants, including modern whales. The goal of this study is to elucidate aspects of Georgiacetus locomotion and behavior that are closely related to both semi-aquatic and aquatic lifestyles by comparing the skeletal morphology of the lumbar region of Georgiacetus to modern mammals of a known lifestyle. Unlike previous studies using muscle scarring, this investigation into those changes in skeletal morphology that occurred during the land-to-sea transition of whale evolution was achieved via multivariate analyses of 17 measurements of lumbar vertebrae from more than 30 modern and extinct mammals. Lumbar vertebrae were used because they likely underwent the most drastic changes during the early stages of whale evolution, as dorsomobile archaecetes evolved relatively quickly from dorsostable artiodactyls.
Whale Origins as a Poster Child for Macroevolution
The last two decades have witnessed an explosive growth in the number of fossils documenting the origins of Cetacea (whales, dolphins, and porpoises). An excellent morphological series of transitional cetaceans is now available to document the transition from land to sea, and many sophisticated analyses detail the biology of these archaic cetaceans. The origin of whales now offers a spectacular example of evolutionary change, allowing us to chart changes in anatomy and physiology as whales first moved into the water and then gradually explored the open seas.
So, no, it is not "a good article for your thread." It is hogwash and faerie dust.
originally posted by: peter vlar
a reply to: WHWIV
A few differentiations-
1. Organic compounds are the result of activities of living beings while inorganic compounds are created either due to natural processes unrelated to any life form or the result of human experimentation in the laboratory.
2. Inorganic compounds can make salt, while organic cannot.
3. Organic compounds contain carbon, while inorganic do not.
4. Organic compounds have carbon-hydrogen bonds, while inorganic do not.
5. Inorganic compounds contain metal atoms, whereas organic compounds do not.
6. Organic compounds are biological and inorganic are mineral in nature.
7. Organic compounds are part of a class of chemical compounds the molecules of which contain carbon and hydrogen, while inorganic compounds mostly comprise of metal containing compounds even if they happen to exist in living organisms.
originally posted by: FearYourMind
Technically evolution goes all the way back to the beginning of time and space. So rather than focusing on apes, I focus on what created the universe and existence itself.
originally posted by: Krazysh0t
So much inaccuracy in this post...
For one, we DO have tons of fossils that depict different stages of evolutionary development for MANY if not most of the species on the planet.
originally posted by: rockpaperhammock
originally posted by: FearYourMind
a reply to: JUhrman
I've been done. It's like arguing with a bunch of people who claim to know everything about everything. There is never a debate because both sides bring zero to the table. Yet, if someone sheds light on the fact that we know nothing they get ridiculed. Enjoy walking through life with your illusions of facts from fiction.
Right and you are one of those people too.... You brought nothing new to the debate...we could just as easily argue that you claimed to know everything....in my first post I wrote we don't know the end result...and no one flamed me. No one on the planet knows 100% sure of anything in regards to evolution or god..no one...anyone who says they do is full of #. And that goes for both sides. And you will be enjoying the same illusions and facts from fiction.
originally posted by: Prezbo369
a reply to: rockpaperhammock
What always pisses me off about this stuff is that evolution is a theory...its a good theory..and the best the scientific community has. But it isn't the Law of Evolution....its a theory. Religious nuts like to jump in and bash it anyway they can to prove their god....
They (the nuts) often use the 'its just a theory' argument asthough it's just a guess, an idea. That would be called a hypothesis in science, while a scientific theory is a comprehensive explanation of a phenomenon. It's basically the highest standard in science.
originally posted by: FearYourMind
I'm sorry, but the majority of intelligent ATS members left years ago. Sorry if I touched a nerve Barcs, but a science denier I am not and I'm tired of repeating my stance regarding the universe and evolution. I'll leave so you guys can share your infinite knowledge. I'll guarantee you this thread doesn't get humanity any closer to the answers. Even with all the so called "intelligent folks" who understand science. Good luck though.
Well, is this forum all about my theory now? I'm wanting to hear some of your intelligent insights. It's been said already that I am a d**khead, ignorant and I've been repeatedly ridiculed for what I've shared. So sorry if I sound like a d**khead, but I was kind of blind sided by the lack of respect and civil discussion I was hoping to have. So what if you disagree. Such negative energy and it's contagious.
originally posted by: Blue_Jay33
So saying, " BUT, They are different fields of science" is the most irrelevant point in this whole debate, nobody is saying they haven't been classified and defined that way by humans. Reality still stands and it's all linked together.
originally posted by: PhotonEffect
originally posted by: Krazysh0t
So much inaccuracy in this post...
For one, we DO have tons of fossils that depict different stages of evolutionary development for MANY if not most of the species on the planet.
Sorry, but no. We DO NOT have a fossil record that depicts most of the species on the planet. On the contrary, we know next to nothing about most of the species that have ever existed.
originally posted by: TinfoilTP
originally posted by: Blue_Jay33
a reply to: peter vlar
Philosophical debate that is sincere is not trolling.
Sometimes the reactions can be entertaining as well.
Here is a good article for your thread.
Problem 5: Abrupt Appearance of Species in the Fossil Record Does Not Support Darwinian Evolution
Source
They even get into and debunk the often mentioned Whale land to water scenario cited by evolutionists,
Whale evolution now runs into a severe problem. The fossil record requires that the evolution of whales from small land mammals would have to have taken place in less than 10 million years. That may sound like a long time, but it actually falls dramatically short, especially given that whales have small population sizes and long generation times. Biologist Richard Sternberg has examined the requirements of this transition mathematically and puts it this way: "Too many genetic re-wirings, too little time."
originally posted by: dragonridr
originally posted by: [post=19267392]PhotonEffect
Well depends on what your looking at larger mamal's like yes we do if your talking small ones like rodents we hardly have any. So guess it depends on which side of the coin you look at. Want to know horses cows foxes bears lions tigers etc they are almost complete.
I've never understood why folks equate not knowing everything to knowing next to nothing. They act as if they KNOW how much we don't know, but they don't. It's just a baseless argument. Just because we don't know everything, doesn't mean that what we DO know is wrong or faulty. It's a ridiculous argument.
originally posted by: Blue_Jay33
I certainly believe in adaptation and a certain level of species drift. I also believe dinosaurs lived millions of years before humans and when they died they left fossils. What I don't believe is that non-organic matter spontaneously became organic and then spontaneously became a one celled organism, then it in turn over millions of years evolved into both genders in every species until humanity happened. I have threads on both those topics right now, but this one is on fossils
originally posted by: Blue_Jay33
If that did happen there would be millions of missing link skeletal remains of both species and genders in between.
And what do we have today for the fossil record, not that. And even the carbon dating is flawed, it's not 100% accurate.
originally posted by: Blue_Jay33
As an example, this guy if you found his skeletal remains from 40 million years ago, it could be thought to be the ancestor to a much bigger dinosaur, in the evolutionary line of development, but he actually isn't, but he stayed the same, 40 million years latter he is still the same.