Fossilised Pikaia gracilens.
Credit: Jean-Bernard Caron/Royal Ontario Museum
OTTAWA: The origins of humans and other vertebrates have been traced to a worm that swam in the oceans half a billion years ago.
A new analysis of fossils unearthed in the Canadian Rockies determined that the extinct Pikaia gracilens is the most primitive known member of the chordate family, which today includes fish, amphibians, birds, reptiles and mammals.
The research, published in the British scientific journal Biological Reviews this week, identified a notochord (or rod) that would become part of the backbone in vertebrates, and skeletal muscle tissue called myomeres in 114 fossil specimens of the creature. They also found a vascular system.
"The discovery of myomeres is the smoking gun that we have long been seeking," said the study's lead author, Simon Conway Morris of the Cambridge University in England. "Now with myomeres, a nerve chord, a notochord and a vascular system all identified, this study clearly places Pikaia as the planet's most primitive chordate. So, next time we put the family photograph on the mantle-piece, there in the background will be Pikaia."
Humans' humbling origin
The first specimens of Pikaia were collected by early explorers of the Burgess Shale in 1911. But the animals were overlooked as an ancestor of earthworms or eels.
It was not until the 1970s that Morris suggested the 5-cm-long, sideways-flattened, somewhat eel-like animal that likely swam by moving its body in a series of side-to-side curves could be the earliest known member of the chordate family.
"In particular, it was our use of an electron microscope that allowed us to see very fine details of its anatomy," said co-author Jean-Bernard Caron, an assistant professor of ecology and evolutionary biology at the University of Toronto in Canada. "It's very humbling to know that swans, snakes, bears, zebras and, incredibly, humans all share a deep history with this tiny creature no longer than my thumb."
"worm"
Chordates aren't actually worms.
and they are sure of the
and they are sure of the billion years? I'm from worms? What a joke!
origins of .....
O great , so now we gotta Ape a worm .no way! Bad enough that we have to have brown bread instead of white...... Scientists have been coming up with theories and retracting them for ions.Nobody's going to call me a worm!
We are all of the elements, nitrogen,oxygen,helium ,watervapours etc.as explained 1300 yrs. ago in the Bible and more explicitly in the Quran....... the Ape is 90 + as is the pig, the d.n.a of man...gifted to man in substituting body parts and correcting his ailments etc., as we are witnessing today.But Adam and Eve(O.T.B.P.) were from Heaven.As in everything (All of 1God's creations), they will all fall short of the D.N.A. of man. All natures creations ,different but subservient and created for a purpose and that purpose is ..."He taught Adam ,the name of His Creations". We are here to learn and discover. Confident that the will soon 'unearth' something elce soon. Tarek Siddick.
Boo doom buh dum bum... WAAAAAAAHHH
Straw Man fallacy: evolutionary theory doesn't claim that humans are worms, in this instance its saying that we evolved FROM a type of worm. Similarly we share an ancestor WITH all primates, most recently with chimps and bononos. You're referencing a misunderstanding of the theory, hence you've created a 'straw' version of evolution.
Yet evolution by mere chance
Yet evolution by mere chance is accepted without evidence at the molecular and genetic level. In fact at this level, Darwin's theory breaks down. This is not to mention the lack of transitional forms for organs and tissues found within species.
Bible & Quran?? Helium??
The human body does not contain Helium. Where in the Bible or Quran does it say anything about the elements, exactly? These are the elements are body consists of:
1.Oxygen (65%)
2.Carbon (18%)
3.Hydrogen (10%)
4.Nitrogen (3%)
5.Calcium (1.5%)
6.Phosphorus (1.0%)
7.Potassium (0.35%)
8.Sulfur (0.25%)
9.Sodium (0.15%)
10.Magnesium (0.05%)
*Copper, Zinc, Selenium, Molybdenum, Fluorine, Chlorine, Iodine, Manganese, Cobalt, Iron (0.70%)
** Lithium, Strontium, Aluminum, Silicon, Lead, Vanadium, Arsenic, Bromine (trace amounts)
You are right, your
You are right, your explanation is more rational and possible. God? what a ignorant idea.
Worm Origins
Cosmos is a serious magazine for serious ,intelligent comment. Please edit the "nutters" out.
asd
theories are created to be proven if it is true or not...,.,., its just a theory., wats da problem???
Actually we have been
Actually we have been upgraded, we used to come from primordial slime, right? At least that was what we were taught in the 70's. After 40 years we now come from worms... hooray! I was just wondering though, with all the species of fossils found thus far and given the evidence for the explosive emergence of species, how come the transitional forms are so sparse as to almost be absent? Just asking.