Posted on 02/08/2005 3:50:43 AM PST by PatrickHenry
A group of four-footed mammals that flourished worldwide for 40 million years and then died out in the ice ages is the missing link between the whale and its not-so-obvious nearest relative, the hippopotamus.
The conclusion by University of California, Berkeley, post-doctoral fellow Jean-Renaud Boisserie and his French colleagues finally puts to rest the long-standing notion that the hippo is actually related to the pig or to its close relative, the South American peccary. In doing so, the finding reconciles the fossil record with the 20-year-old claim that molecular evidence points to the whale as the closest relative of the hippo.
"The problem with hippos is, if you look at the general shape of the animal it could be related to horses, as the ancient Greeks thought, or pigs, as modern scientists thought, while molecular phylogeny shows a close relationship with whales," said Boisserie. "But cetaceans – whales, porpoises and dolphins – don't look anything like hippos. There is a 40-million-year gap between fossils of early cetaceans and early hippos."
In a paper appearing this week in the Online Early Edition of the Proceedings of the National Academy of Sciences, Boisserie and colleagues Michel Brunet and Fabrice Lihoreau fill in this gap by proposing that whales and hippos had a common water-loving ancestor 50 to 60 million years ago that evolved and split into two groups: the early cetaceans, which eventually spurned land altogether and became totally aquatic; and a large and diverse group of four-legged beasts called anthracotheres. The pig-like anthracotheres, which blossomed over a 40-million-year period into at least 37 distinct genera on all continents except Oceania and South America, died out less than 2 and a half million years ago, leaving only one descendent: the hippopotamus.
This proposal places whales squarely within the large group of cloven-hoofed mammals (even-toed ungulates) known collectively as the Artiodactyla – the group that includes cows, pigs, sheep, antelopes, camels, giraffes and most of the large land animals. Rather than separating whales from the rest of the mammals, the new study supports a 1997 proposal to place the legless whales and dolphins together with the cloven-hoofed mammals in a group named Cetartiodactyla.
"Our study shows that these groups are not as unrelated as thought by morphologists," Boisserie said, referring to scientists who classify organisms based on their physical characteristics or morphology. "Cetaceans are artiodactyls, but very derived artiodactyls."
The origin of hippos has been debated vociferously for nearly 200 years, ever since the animals were rediscovered by pioneering French paleontologist Georges Cuvier and others. Their conclusion that hippos are closely related to pigs and peccaries was based primarily on their interpretation of the ridges on the molars of these species, Boisserie said.
"In this particular case, you can't really rely on the dentition, however," Boisserie said. "Teeth are the best preserved and most numerous fossils, and analysis of teeth is very important in paleontology, but they are subject to lots of environmental processes and can quickly adapt to the outside world. So, most characteristics are not dependable indications of relationships between major groups of mammals. Teeth are not as reliable as people thought."
As scientists found more fossils of early hippos and anthracotheres, a competing hypothesis roiled the waters: that hippos are descendents of the anthracotheres.
All this was thrown into disarray in 1985 when UC Berkeley's Vincent Sarich, a pioneer of the field of molecular evolution and now a professor emeritus of anthropology, analyzed blood proteins and saw a close relationship between hippos and whales. A subsequent analysis of mitochondrial, nuclear and ribosomal DNA only solidified this relationship.
Though most biologists now agree that whales and hippos are first cousins, they continue to clash over how whales and hippos are related, and where they belong within the even-toed ungulates, the artiodactyls. A major roadblock to linking whales with hippos was the lack of any fossils that appeared intermediate between the two. In fact, it was a bit embarrassing for paleontologists because the claimed link between the two would mean that one of the major radiations of mammals – the one that led to cetaceans, which represent the most successful re-adaptation to life in water – had an origin deeply nested within the artiodactyls, and that morphologists had failed to recognize it.
This new analysis finally brings the fossil evidence into accord with the molecular data, showing that whales and hippos indeed are one another's closest relatives.
"This work provides another important step for the reconciliation between molecular- and morphology-based phylogenies, and indicates new tracks for research on emergence of cetaceans," Boisserie said.
Boisserie became a hippo specialist while digging with Brunet for early human ancestors in the African republic of Chad. Most hominid fossils earlier than about 2 million years ago are found in association with hippo fossils, implying that they lived in the same biotopes and that hippos later became a source of food for our distant ancestors. Hippos first developed in Africa 16 million years ago and exploded in number around 8 million years ago, Boisserie said.
Now a post-doctoral fellow in the Human Evolution Research Center run by integrative biology professor Tim White at UC Berkeley, Boisserie decided to attempt a resolution of the conflict between the molecular data and the fossil record. New whale fossils discovered in Pakistan in 2001, some of which have limb characteristics similar to artiodactyls, drew a more certain link between whales and artiodactyls. Boisserie and his colleagues conducted a phylogenetic analysis of new and previous hippo, whale and anthracothere fossils and were able to argue persuasively that anthracotheres are the missing link between hippos and cetaceans.
While the common ancestor of cetaceans and anthracotheres probably wasn't fully aquatic, it likely lived around water, he said. And while many anthracotheres appear to have been adapted to life in water, all of the youngest fossils of anthracotheres, hippos and cetaceans are aquatic or semi-aquatic.
"Our study is the most complete to date, including lots of different taxa and a lot of new characteristics," Boisserie said. "Our results are very robust and a good alternative to our findings is still to be formulated."
Brunet is associated with the Laboratoire de Géobiologie, Biochronologie et Paléontologie Humaine at the Université de Poitiers and with the Collège de France in Paris. Lihoreau is a post-doctoral fellow in the Département de Paléontologie of the Université de N'Djaména in Chad.
The work was supported in part by the Mission Paléoanthropologique Franco-Tchadienne, which is co-directed by Brunet and Patrick Vignaud of the Université de Poitiers, and in part by funds to Boisserie from the Fondation Fyssen, the French Ministère des Affaires Etrangères and the National Science Foundation's Revealing Hominid Origins Initiative, which is co-directed by Tim White and Clark Howell of UC Berkeley.
Newton predicted that the world would end in 2060. Better tell the Grandkids ...
The review makes nothing clear and the "logical errors" sounds like wishful thinking on their part.
Here's what Sternberg says about it. He doesn't identify by name the three scientists who reviewed the work. He does, however, note that Dr. Roy McDiarmid, President of the Council of the BSW, reviewed the peer-review file and concluded that all was in order.
How I "want it" is utterly irrelevant to the issue, which is the content and meaning of Rev. Dyson Hague's essay, The Doctrinal Value of the First Chapters of Genesis, which you posted. My goal here is to accurately understand the claims that Hague makes in his article. Your goal is to read your opinions into Hague's text.
You are reading your ICR style creationism into Hague's text. It isn't there.
Hague doesn't say, or even imply, that the "days" in Genesis are twenty-four hours. Indeed it should be clear that he contemplates the possibility that they are long ages if you examine the passage I showed you earlier. Hauge first summaries the sequence of creation and then makes a point, in favor of the veracity of Genesis, of highlighting the "comparability" of this sequence to the findings of eminent scientists, which is to say conventional geologists (such as he cites elsewhere, i.e. Dana, Dawson, etc, all of whom were old-earthers).
How are six twenty four hour days, or any such brief period, as your view requires, "comparable" to the vast ages of mainstream geology?
Why does Hague refer to the earth "gradually being fitted for God's children"?
Now, it may be that Hague considered a young earth scheme of some type a possibility. If so it is only hinted at, at best, when Hague precedes a reference to "those countless aeons" the trilobite existed with: "If, as they [the geologists] say, the strata tell the story of countless aeons..."
So I'll give you an "if". Other than that you've got nothing.
Let's summarize:
Hauge, via the credence he gives to the account in Genesis of the origin of races, suggests that the origin of mankind is recent relative to the span of written history. I agree with you completely on this point.
Your next step, however, in claiming that he was thereby affirming that the earth, or life apart from humanity, was comparably recent is completely gratuitous. It's not in the text explicitly, nor is there anything in the text that justifies it by inference.
Your problem goes beyond the fact that Hague says nothing about the Genesis "days" being short. It's also the historical context. Debate about the antiquity of man had been raging for four of five decades by the time this essay was written. All of those debates assumed an ancient earth, and that other lifeforms had preceded man by long ages. Because of this context, if Hague was intending to put forward a different view he would not have left it to inference. He would have been explicit because he would have understood that, otherwise, any educated contemporary reader would have misinterpreted him, assuming the then standard framing of the question of man's antiquity.
The FOXP2 gene seems to also be critical in vocal learning even in widely different species:
Fascinating.FoxP2 Expression in Avian Vocal Learners and Non-Learners
Abstract: Most vertebrates communicate acoustically, but few, among them humans, dolphins and whales, bats, and three orders of birds, learn this trait. FOXP2 is the first gene linked to human speech and has been the target of positive selection during recent primate evolution. To test whether the expression pattern of FOXP2 is consistent with a role in learned vocal communication, we cloned zebra finch FoxP2 and its close relative FoxP1 and compared mRNA and protein distribution in developing and adult brains of a variety of avian vocal learners and non-learners, and a crocodile. We found that the protein sequence of zebra finch FoxP2 is 98% identical with mouse and human FOXP2. In the avian and crocodilian forebrain, FoxP2 was expressed predominantly in the striatum, a basal ganglia brain region affected in patients with FOXP2 mutations. Strikingly, in zebra finches, the striatal nucleus Area X, necessary for vocal learning, expressed more FoxP2 than the surrounding tissue at post-hatch days 35 and 50, when vocal learning occurs. In adult canaries, FoxP2 expression in Area X differed seasonally; more FoxP2 expression was associated with times when song becomes unstable. In adult chickadees, strawberry finches, song sparrows, and Bengalese finches, Area X expressed FoxP2 to different degrees. Non-telencephalic regions in both vocal learning and non-learning birds, and in crocodiles, were less variable in expression and comparable with regions that express FOXP2 in human and rodent brains. We conclude that differential expression of FoxP2 in avian vocal learners might be associated with vocal plasticity.
If I worked in a genetics lab with the appropriate equipment and techniques, the first thing I'd want to try would be to replace a parrot's FOXP2 gene with the human version, then hatch a chick with the resulting genome and see whether there's a quantum leap in its ability to learn and use grammar-based language.
enjoy your little book
Maybe I missed it.
Did anyone "get" your post?
Wouldn't that be the Hindu numerals which Arabs transmitted to the west?
More like what a book says God said. When the evidence contradicts the writing, it comes down to, "who're you going to believe? Me, or you're own lying eyes."
Now I have seen everything. They want everyone to accept their view on the Bible, but discourage people from actually reading the Bible!
That is exactly why creationist (YECers) whatever are a stain on Christianity.
Whatever you think it says, it doesn't.
Synchronic dating and 39 other methods date the Earth and the universe as old. [14 some billion years for the universe and some 4 billion years for the Earth]
Carbon dating only goes back 50,000 years so don't come back with anything about that or I may die of laughter.
They missed Christ's birth by about 4 years too. 4BC is no accepted.
Learn to read, it does say just that.
You just refise to believe what the Bible says.
You need to face that.
Here we call a creationist someone only if they believe in nonsense and are pretty much outside the ability of logic to understand. It is those that believe in a 6000 year old Earth and that Noah could really take all those animals on a small wooden boat for a year, those that will not accept Theories as scientific fact etc.
Just because someone believes God created everything, doesn't mean he or she is a creationist. We, who have full brain functioning, do not appreciate being lumped with creationists.
It's there, you just refuse to accept it.
Not my fault you want to believe in the evolutionary fairy tale
Who cares what Newton thought about evolution? He was a mathemetician not a biologist.
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