Factbites
 Where results make sense
About us   |   Why use us?   |   Reviews   |   PR   |   Contact us  

Topic: Pikaia


Related Topics

In the News (Mon 6 Jul 09)

  
  Evrim Masalı. com - Harun Yahya
Evrimciler, balıkların pikaia gibi omurgasız deniz canlılarından, amfibiyenlerin ve günümüz balıklarının "atasal" bir balıktan, sürüngenlerin amfibiyenlerden, kuşların ve memelilerin ayrı ayrı sürüngenlerden ve en son olarak insanların ve günümüz maymunlarının ortak bir atadan evrimleştiklerini iddia ederler.
Evrim teorisi, pikaia gibi ilk kordalıların zamanla balıklara dönüştüğünü varsayar.
Pikaia fosili (alttaki kare çerçeve içinde) Evrimciler pikaia adlı canlının balıkların atası olduğunu iddia ettiler.
www.evrimmasali.com /4.html   (11103 words)

  
  Pikaia   (Site not responding. Last check: 2007-10-31)
Pikaia is a Middle Cambrian fossil found near Mount Pika in the Burgess Shale by Walcott.
Described by him in 1911 and classified as a Polychaete worm, based on the obvious and regular segmentation of the body.
Conway Morris placed Pikaia gracilens in the chordates in 1979, which probably makes it one of the oldest ancestors of the modern vertebrates.
pedia.newsfilter.co.uk /wikipedia/p/pi/pikaia.html   (73 words)

  
 National Museum of Natural History - Paleobiology   (Site not responding. Last check: 2007-10-31)
Living among the variety of ancestral forms that make up the BSF is this earliest known representative of the phylum to which we ourselves belong.
Pikaia is not a vertebrate - no one can say if this particular creature is our direct predecessor.
Nevertheless, Pikaia is a representative member of the chordate group from which we undoubtedly arose.
www.nmnh.si.edu /paleo/shale/ppikaia.htm   (244 words)

  
 A scuola di bugie - E' nato Pikaia
Pikaia è infatti un nostro antenato vissuto 500 milioni di anni fa; nessun nome è più adatto per il nuovo portale europeo dedicato completamente all'evoluzionismo.
In pratica Pikaia opera uno screening su una impressionante mole di nuovo sapere, dato che sono circa 300.000 le ricerche scientifiche che si producono ogni anno nel mondo.
Pikaia rappresenta quindi una fonte utile e attendibile non solo per insegnanti e ricercatori, ma anche per il grande pubblico.
ascuoladibugie.blogosfere.it /2006/04/e_nato_pikaia.html   (627 words)

  
 Pikaia -- Facts, Info, and Encyclopedia article   (Site not responding. Last check: 2007-10-31)
It resembles a living chordate commonly known as the (Small translucent lancet-shaped burrowing marine animal; primitive forerunner of the vertebrates) lancelet.
Averaging about 40mm in length, Pikaia swam above the seafloor using its body and an expanded tail fin.
Pikaia may have filtered particles from the water as it swam along.
www.absoluteastronomy.com /encyclopedia/P/Pi/Pikaia.htm   (113 words)

  
 Chapter 3: Parallel Genetic Algorithm
PIKAIA is a self-contained, genetic-algorithm-based optimization subroutine developed by Paul Charbonneau and Barry Knapp at the High Altitude Observatory in Boulder, Colorado.
PIKAIA incorporates only the two basic genetic operators: uniform one-point crossover, and uniform one-point mutation.
The mutation rate can be dynamically adjusted during the evolution, using either the linear distance in parameter-space or the difference in fitness between the best and median solutions in the population.
bullwinkle.as.utexas.edu /travis/metcalfe/node8.htm   (2460 words)

  
 Encyclopedia: Pikaia   (Site not responding. Last check: 2007-10-31)
Families Asymmetronidae Branchiostomidae The lancelets (subphylum Cephalochordata, and traditionally known as the amphioxus) are a group of primitive chordates.
During his re-examination of the Burgess Shale fauna in 1979, Paleontologist Conway Morris placed Pikaia gracilens in the chordates, making it perhaps the oldest known ancestor of modern vertebrates.
Averaging about 40 mm in length, Pikaia swam above the seafloor using its body and an expanded tail fin.
www.nationmaster.com /encyclopedia/Pikaia   (453 words)

  
 Forever Tigers - Evolution of the Tiger
Fishes with jaws evolved from jawless fishes about 400 million years ago, and the jawless fishes, Class Agnathan (today represented only by the hagfishes and lampreys), were the first true vertebrates to evolve i.e., the first animals to posses a true backbone and appeared about 510 million years ago.
Antecedent to the Agnathans were primitive chordates (tough notochord around spinal nerve cord, but no bones) such as Pikaia, found in the famous Burgess shale - a collection of fossils, including some soft body parts, from the Cambrian age.
Pikaia, a worm-like animal (in fact originally misidentified as an annelid worm), about 2 inches long with a long flattened tail, dates back to the Cambrian, about 535 million years ago, and is the oldest know chordate.
www.forevertigers.com /evolution.htm   (1451 words)

  
 (continued Subject: SWAA Lecture Date: 18 Jan 1993 16:25:42 GMT Readers familiar with Goul   (Site not responding. Last check: 2007-10-31)
Walcott classified Pikaia as a worm, but a more recent study concludes that the creature was a member of the phylum Chordata, which includes the subphylum Vertebrata, which includes us.
That for Gould means that Pikaia might be our ancestor, which implies that, unlike many other Burgess Shale creatures, it left descendants.
If Pikaia had not survived the mass extinctions that killed off so many other Cambrian fossil creatures, we would never have evolved.
www.skepticfiles.org /evolut/swaa5pej.htm   (1224 words)

  
 Geological Association of Canada - Medals and Awards   (Site not responding. Last check: 2007-10-31)
The Pikaia Award is named after Pikaia, an early cephalochordate known from the Burgess Shale.
The Pikaia Award is awarded biennially in even-numbered years by the Paleontology Division.
It is awarded in recognition of a recent contribution to research on any aspect of Canadian paleontology, or by a Canadian to paleontology that is judged to constitute an outstanding accomplishment in the field.
www.gac.ca /MEDALS/paleo.html   (217 words)

  
 Cryptozoology.com
>Pikaia seems to be the earliest fossil chordate, which appears to be something
Well, while Pikaia certainly is a very nice archetypal chordate, its trophy for oldest chordate has been rescinded - theres another Early Cambrian Lagerstätten besides the Burgess Shale, the Chengjiang Fauna of Yunnan Province, Peoples Republic of China which is between 10-15 million years older than the Burgess.
Cathaymyrus and Zhongxiniscus are generalised basal chordates similar to Pikaia (Z. seems to be a tad more advanced).
www.cryptozoology.com /forum/topic_view_thread.php?tid=12&pid=240927   (473 words)

  
 Solar Research at the High Altitude Observatory
Pikaia Gracilens, a little worm-like beast that crawled in the mud of a long gone seafloor of the Cambrian era, 530 million years ago.
While not particularly impressive in the tooth and claw department, Pikaia is believed to be the founder of the phylum Chordata, whose subsequent evolution had consequences still very much felt today by the rest of the ecosystem.
PIKAIA in IDL and f90, and parallel PIKAIA
www.hao.ucar.edu /Public/models/pikaia/pikaia.html   (3135 words)

  
 Fred Heeren, Evolution and Cognition Journal
He mentions no brain, eyes, or other sensory organs when describing Pikaia in his popular book; even the possibility of a head seems remote in an animal whose anterior end, in his illustration, splits into two (GOULD 1989).
Even GOULD’s Pikaia, though used to illustrate Cambrian chordates in vertebrate textbooks, no longer looked convincing, since it lacked many of the chordate features claimed by the more recent finds.
Though paleontologists of these various discoveries continue to contend with one another over whose specimens are ancestral to whose—and whose are true chordates—all agree that chordates have now been found in the early Cambrian (ENSERINK 1999; DZIK 1995).
www.fredheeren.com /evocognition2.htm   (2416 words)

  
 EvoWeb - Software - PIKAIA
PIKAIA (pronounced 'pee-kah-yah') is a general purpose function optimization FORTRAN-77 subroutine based on a genetic algorithm.
PIKAIA is a public domain software available electronically from the anonymous ftp archive of the High Altitude Observatory.
PIKAIA was written by Paul Charbonneau and Barry Knapp, both at HAO/NCAR.
evonet.lri.fr /evoweb/resources/software/record.php?id=325   (107 words)

  
 Index of /archive/pikaia   (Site not responding. Last check: 2007-10-31)
The file also includes a driver calling PIKAIA, a fitness function defining a maximization problem for a 2-D landscape, a ranking subroutine, and a random number generator.
Written for PIKAIA 1.0, very nearly everything in there remains relevant ti PIKAIA 1.2, Beware, it is a large file.
In case of problem, queries should be e-mailed to pikaia@hao.ucar.edu While we do not formally commit to provide user support, at this point we remain willing to answer queries; we make no promises, however, as to response time.
download.hao.ucar.edu /archive/pikaia   (328 words)

  
 ¿Por qué sobrevivió Pikaia?.- Aula Crítica Péguy   (Site not responding. Last check: 2007-10-31)
Si, en cambio, digo que un pequeño fósil llamado Pikaia y encontrado en ese yacimiento tiene que ver con el hecho de que nosotros estemos aquí ahora ante esta pantalla, seguro que la actitud del lector cambia.
Entre los géneros que lograron sobrevivir se encuentra Pikaia, el primer cordado conocido, o, lo que es lo mismo, el primer ejemplar registrado del tipo de organización a que nosotros mismos pertenecemos.
Pikaia es el eslabón perdido y final en nuestro relato de contingencia, la conexión directa entre la diezmación de Burgess Shale y la eventual evolución humana...
www.ucm.es /info/zoo/Vertebrados/JADiaz/evolucion.htm   (5000 words)

  
 Pikaia Ltd
The Pikaia Web Hosting service was launched today.
Within Pikaia Limited, we place a great deal of emphasis upon adherence to established project design and management methodologies.
Pikaia Ltd provides standard web hosting and reseller hosting on a leading-edge LAMP (Linux, Apache, MySQL and PHP) hosting environment based upon the PikNix software platform.
pikaia.co.nz   (113 words)

  
 Pikaia's Den ~ fun and frolics with Adam Morson
A new feature for Pikaia's Den, an opportunity to keep up with Adam's latest reads.
For now he will complain about the state of the nation, ponder the imponderables, and despair at Tottenham Hotspur's transfer activity.
Join him on this ordinary journey, only at Pikaia's Den.
www.freewebs.com /europeancycletour   (299 words)

  
 Trilobite Sumo Robot   (Site not responding. Last check: 2007-10-31)
After whole months without touching a single line of code from Pikaia, this weekend we started to use Pikaia as a test robot for Trilobite.
Even though Pikaia is really buggy, testing Trilobite against Pikaia revealed some flaws in Trilobite's "personality".
Sure, Trilobite is stronger and faster than Pikaia but sometimes Pikaia looked smarter, and Pikaia's code that we have is not the code that we used in the last competition, far better than the current code.
www.mecanic.net /trilobite/index.php?show=comments&id=17   (129 words)

  
 Historia de Pikaia   (Site not responding. Last check: 2007-10-31)
Pikaia nació en septiembre de 1999, como una iniciativa de Hector Fabio Rivera e Isadora Angarita, estudiantes de Biología de la Universidad del Valle.
En una de esas reuniones, escogimos “Pikaia” como el nombre de nuestro nuevo grupo de trabajo en Zoología, en honor al primer registro fósil de cordado conocido en el mundo y procedente de Burgess Shale.
Pikaia gracilens es una pequeña criatura cintiforme comprimida lateralmente de unos cinco centímetros de longitud, pertenece al Cámbrico Medio y es “un hito de la historia del phylum al que todos los vertebrados, el hombre incluido, pertenecen”.
www.univalle.edu.co /~pikaia/historia.htm   (371 words)

  
 2001BILLINGS   (Site not responding. Last check: 2007-10-31)
Jisuo Jin (University of Western Ontario) was the inaugural winner of Paleontology Division's new Pikaia Award; it was presented to him on Saturday, September 28, 2002 at CPC-2002 (Ottawa), in recognition of his recent outstanding contributions to the paleontology of Ordovician and Silurian brachiopods.
This consistently constrains his investigations in a way that enables him to build a growing explanation of the various factors controlling contemporary brachiopod assemblages across the Laurentian continent during a brief interval of earth history marked by mass extinction, continental glaciation, and the global geographic and tectonic events associated with an inter-systemic boundary.
Finally, while it was a great pleasure serving on the executive committee with him, even better was presenting him with his richly deserved Pikaia Award.
publish.uwo.ca /~ctsujita/2002pikaia.html   (689 words)

  
 Evolution and paleontology (from cephalochordate) --  Encyclopædia Britannica
A few fossils have been interpreted as cephalochordates, but few of these determinations are well founded.
A good possibility is Pikaia, a fossil discovered in the Burgess Shale (Middle Cambrian, about 530 million years old).
Pikaia has myotomes and what looks like a notochord, indicating that it is…
www.britannica.com /eb/article?tocId=49515   (1016 words)

  
 Mailgate: sci.engr.civil: Genetic algorithms and water quality modeling   (Site not responding. Last check: 2007-10-31)
An Excel VBA translation of the PIKAIA genetic algorithm is available at the following link: http://www.ecy.wa.gov/programs/eap/models/pikaia.zip PIKAIA is a general purpose function optimization subroutine based on a genetic algorithm.
I translated the PIKAIA algorithm into Excel's VBA language for use in a water quality modeling framework.
An application of the PIKAIA algorithm for modeling of water quality in streams and rivers is also available at this Web page (click on the link to download the beta version of QUAL2Kw): http://www.ecy.wa.gov/programs/eap/models/ Greg Pelletier gpel461@ecy.wa.gov
mailgate.supereva.it /sci/sci.engr.civil/msg18245.html   (101 words)

  
 Aikido Shugyo Dojo (Toronto) Newsletter - Dec 1996 - Jan 1997
The first animal to embrace the ocean floor with backbone.
Pikaia was a bottom-feeder who never washed its gi, never did an iriminage or complicated sums, never ran for a streetcar, never read Canterbury Tales, made a stir fry or went to Yuk Yuk's, but somehow still went about its business, knowing what it had to do.
Did Pikaia scrunch up the tissue and muscle nearest its head whenever it saw a trilobite approach?
www.shugyo.com /199612/jennifr1.html   (607 words)

  
 Mathtools.net : Excel/Genetic algorithms
PIKAIA is a general purpose function optimization subroutine based on a genetic algorithm.
Greg Pelletier translated the PIKAIA algorithm into Excel's VBA language for use in a water quality modeling framework.
An application of the PIKAIA algorithm for modeling of water quality in streams and rivers is also available at this Web page.
www.mathtools.net /Excel/Genetic_algorithms   (279 words)

  
 Contingency Is Life   (Site not responding. Last check: 2007-10-31)
This odd creature, known as Pikaia (pronounced pik ea), existed some 500 million years ago.
Well the answer is that Pikaia was probably lucky.
As hard as it might be to accept, luck is part of nature and how it works.
www.mc.maricopa.edu /dept/d10/asb/anthro2003/origins/selection/contingency.html   (550 words)

  
 Evolution Fairytale Forum -> Exposing The Evolutionist’s Sleight-of-hand
FYI, you notice they in so many words question Pikaia as an legit intermediate.
So either the case has been exaggerated, there is a conspiracy to keep the truth hidden, or there are lots of reports like this one, but everyone copy/pastes the same one.
It makes me wonder how closely Modulus read my article since he touted Pikaia as an intermediate and failed to notice I addressed this in my article.
www.evolutionfairytale.com /forum/index.php?showtopic=145   (1328 words)

  
 .all about joey.: August 08, 2004   (Site not responding. Last check: 2007-10-31)
ehehe..) yeah so anyway according to him, pikaia were on the verge of extinction because they were so defenseless and so easy for other bigger animals to prey on.
pikaia were smart (NOW you know where the genes came from..
and that it actually took millions of years for pikaia to evolve into current-day vertebrae..
gnoyennaoj.blogspot.com /2004_08_08_gnoyennaoj_archive.html   (1064 words)

  
 Duffy: Chordate Origins
Emmonaspis cambrensis, from the Lower Cambrian of Vermont, has been allied with the graptolites, chordates, arthropods, and frond-like organisms since its initial description in 1886 (Conway Morris, 1993).
Even the most widely accepted earliest chordate, Pikaia gracilens, from the Middle Cambrian Burgess Shale, was originally interpreted as a polychaete annelid (Walcott, 1911), but has since been allied with the cephalochordates based on synapomorphies such as chevron shaped myomeres and an anteriorly extending notochord (Conway Morris, 1998).
With the general acceptance of Pikaia as a fossil chordate, the search for earlier material led to finds such as Yunnanozoon lividum (Chen et al.
www.biology.ualberta.ca /courses.hp/biol606/OldLecs/Lecture2K.08.Duffy.html   (971 words)

  
 Evolution of the Vertebrates
The history of the vertebrates may begin with Pikaia, a pre-vertebrate with a notochord, which places it in Phylum Chordata.
The Smithsonian has a sketch of Pikaia (http://nmnhgoph.si.edu/paleo/shale/ppikaia.htm), emphasizing the "muscle blocks" which give Pikaia a segmented appearance.
The color picture of Pikaia's habitat (http://nmnhgoph.si.edu/paleo/shale/pamsci.htm) gives a better illustration of its mode of life.
www.gpc.edu /~pgore/geology/historical_lab/evolutionofvertebrates.htm   (2460 words)

Try your search on: Qwika (all wikis)

Factbites
  About us   |   Why use us?   |   Reviews   |   Press   |   Contact us  
Copyright © 2005-2007 www.factbites.com Usage implies agreement with terms.