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.
My translation would translate "mayim" the word for water as molecules in this passage. The word for firmament "rakia", has nothing to do with water.
To me, the inspired author/s were given a vision of something they were unable to comprehend. The Hebrew was inadequate to explain the vision, since it would have no word for atoms or molecules.
The idea that Gen 2 flood has anything to do with this passage is far-fetched. If it does, it condemns Gen 1 to be as irrelevant as the pagan tale of Noah.
Just trying to bring the apostate back on the Christian reservation. ;-)
oh, dear, now I need to dust off my bible again...
first off:
gen.1:7 - and God made the firmament and divided the waters which were under the firmament from the waters which were above the firmament; and it was so
so: the firmament ain't the water
now, on other gods:
gen.4:22 - and the Lord God said, behold, the man is become as one of us
exodus20:3 - thou shalt have no other gods before me. thou shalt not make unto thee any graven image (icon), or any likeness of any thing (totem symbols, etc...) that is in heaven above, in the earth below, or in the water...Thou shalt not bow down thyself to them nor serve them; for I the Lord thy God am a jealous God...
exodus22:20 - He that sacrificeth unto any god, save unto the Lord only, he shall be utterly destroyed
multiple indications of more than one god: use of the plural, also specific mention to earthly things (presumably critters AND other "things" like material wealth etc...) in ADDITION TO the other gods.
all hurriedly typed from the KJV.
what does the Hebrew say?
and, as a side note, what the hell would "two ouches of gold" be???
heh, any caption :)
Since you've devolved to single sentence bald assertions for the last several rounds, I consider the issue closed and well settled. Thanks.
CHARIOTS OF THE GODS!!!
lol! nice
I know your post was not directed to me, but just out of curiosity, have you ever asked for and received answers to these questions before today?
God created evolution.
Reject evolution is to reject God.
Your logic is faulty.
Now repent!
as an aside:
why do so many modern people operate on the blithe assumption that the ancients were stupid or monumentally unobservant?
I just stepped outside to check on my dog. my house fronts the west. I caught a lovely view of the waning crescent moon.
the full disc of the circumference was plainly evident as a pale lavender (with some orange hints) against the deeper blue of the night sky, with plain visual cues that it is a sphere backlit by light reflected from the earth (volumetric shading); the Mare were discernable; the lit crescent was a brilliant yellow-white, with trace of green and blue on the edges; the terminator also had a bit of volumetric shading.
Now, yes: my eyes are about twice as sensitive to light as is the norm for my species. this is a result of a combination of the effects of one of the inherited mutations I carry that mentioned earlier plus a persistent infection of my tear ducts which causes my tears to act a bit like light-gathering coatings on good optics. Plus, I have keen distance-vision: L20:12/R20:15
OTOH, this condition is far from unique to me, nor is it recent in provenance. There have been people with eyes like mine for a very long time - at least from Roman times. Additionally, one would think that back then the skies were less hazy than they are now.
SURELY the ancients could observe what I have observed.
How has it come to pass that we believe the ancients believed that the moon actually changed its shape???
this is but one example.
don't even get me started on the whole "gods/aliens must have built the pyramids because they are so precise" bullshyte.
which questions?
the trial? hundreds of times - usually a lot of stuttering and mental vaporlock.
if not the trial, to which questions do you refer?
oh, dear, now I need to dust off my bible again...
would suffice, sorry it did not. I was referring to your questions listed in post 1683 regarding other gods.
I don't worship the false idol of logic.
well, as I asked no question in that post, save the one: "what the hell is an ouche of gold?"...
;)
ok.
Yes, I have discussed this issue with some folks before - including catholic (jesuit) priests, protestant ministers, and an orthodox rabbi I accosted once on vacation in NYC.
I didn't get what I would call definitive answers from any of them.
oops: my bad!
also: "what does the hebrew say?"
Sorry, after reading the post again, I see that you did not ask questions about the other gods. MY bad.
That is plain for all to see.
s'okay.
ya wouldn't happen to know what an ouche of gold is, wouldja?
I mean, what? is it a lump of gold someone dropped on their foot, or...?
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