<< Chapter < Page Chapter >> Page >

Activity: critical analysis of Archaeopteryx

Some scientists consider Archaeopteryx to be a transitional fossil between dinosaurs and birds. Other scientists disagree. Below are two arguments given by scientists to support their interpretation that Archaeopteryx is not a transitional fossil between dinosaurs and birds. For each of these arguments, state whether the scientists are questioning the DATA, or the CONCLUSIONS about the Archaeopteryx fossil.

  1. Watkins, Hoyle, Wickramasinghe, Watkins, Rabilizirov and Spetner (1985) published an article where they claimed that the feather impressions of Archaeopteryx were forged. They provide evidence suggesting that chicken feathers were pressed into a cement mix, and these were applied over dinosaur fossils: Watkins, R.S., Fred Hoyle, N.C. Wickramasinghe, J. Watkins, R. Rabilizirov, andL.M. Spetner (1985), “ Archaeopteryx : A Photographic Study,” British Journal of Photography, 132:264-266, March 8.

    These scientists are questioning the DATA / CONCLUSIONS made by other scientists about Archaeopteryx .

  2. Some scientists argue that even if the feathers on Archaeopteryx were not forged, there is no evidence that the fossil is transitional between reptiles and birds, since the fossil is compatible with the fossil of a bird.

    These scientists are questioning the DATA / CONCLUSIONS made by other scientists about Archaeopteryx .

  3. Some scientists argue that birds have been found in younger rocks than the rocks in which Archaeopteryx was found, and so Archaeopteryx cannot be the ancestor to birds.

    These scientists are questioning the DATA / CONCLUSIONS made by other scientists about Archaeopteryx .

  1. Data
  2. Conclusions
  3. Conclusions

In 1938, an East London fisherman caught a deep-sea fish he had never seen, so it was taken to the East London museum, where it was identified as a coelacanthby Professor JLB Smith and his assistant, Marjorie Courtenay-Latimer. This caused an international uproar, because the fish was previously known only fromfossils and had been believed to be extinct. People were amazed that fossil coelacanth found in rock strata 70 –350 million years old could look exactly like the large blue fish before their eyes! This started a search for more specimens and 14 years later, another one was caught off the Comoro Islands inthe Indian Ocean, north of Madagascar and more have been found since, including in deep crevices at St. Lucia in northern KZN.

Coelacanth display
Madge Courtenay-Latimer and the coelacanth

Scientists agree that the coelacanth is probably the oldest living vertebrate and they are thought to be closely related to the freshwater fish that is seenas the ancestor of all land animals. The coelacanth’s internal organs are in many ways similar to those of amphibians, which are the earliest life formsto have colonized land. Unlike amphibians, its spine is supported by a permanent notochord, a cartilage and oil tube – it never develops a bony vertebral column like other fish do. The body is lobe-finned, not ray-finned like modern fish,although it is not known to “walk” on the ocean floor. Many scientists had thought that the coelacanth’s fins looked like“legs” (it was referred to as ‘old four legs’) and that it was in the process of developing limbs for use on land, but here was aspecimen, millions of years later, that still had the same fin structure. Its nostrils are also not blind-ending as in fish; they open into the mouth and can be used for breathing.

Assignment:

The modern coelacanth-finding throws doubt on an assumption palaeontologists use when reasoning about what the fossil record says about extinctions.
  1. What is the assumption the modern coelacanth-finding throws doubt on?
  2. How does the modern coelacanth-finding throw doubt on this assumption ?
An extinction event can be recognised by fossils of that type not being found in higher (i.e. younger) rock. Although no coelacanth fossils are found in rock younger than that assumed to be100 million years old, coelacanths are not extinct: they are alive today (extant).

Questions & Answers

Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
Renato
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
Stoney Reply
why we need to study biomolecules, molecular biology in nanotechnology?
Adin Reply
?
Kyle
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
Adin
why?
Adin
what school?
Kyle
biomolecules are e building blocks of every organics and inorganic materials.
Joe
anyone know any internet site where one can find nanotechnology papers?
Damian Reply
research.net
kanaga
sciencedirect big data base
Ernesto
Introduction about quantum dots in nanotechnology
Praveena Reply
what does nano mean?
Anassong Reply
nano basically means 10^(-9). nanometer is a unit to measure length.
Bharti
do you think it's worthwhile in the long term to study the effects and possibilities of nanotechnology on viral treatment?
Damian Reply
absolutely yes
Daniel
how to know photocatalytic properties of tio2 nanoparticles...what to do now
Akash Reply
it is a goid question and i want to know the answer as well
Maciej
characteristics of micro business
Abigail
for teaching engĺish at school how nano technology help us
Anassong
Do somebody tell me a best nano engineering book for beginners?
s. Reply
there is no specific books for beginners but there is book called principle of nanotechnology
NANO
what is fullerene does it is used to make bukky balls
Devang Reply
are you nano engineer ?
s.
fullerene is a bucky ball aka Carbon 60 molecule. It was name by the architect Fuller. He design the geodesic dome. it resembles a soccer ball.
Tarell
what is the actual application of fullerenes nowadays?
Damian
That is a great question Damian. best way to answer that question is to Google it. there are hundreds of applications for buck minister fullerenes, from medical to aerospace. you can also find plenty of research papers that will give you great detail on the potential applications of fullerenes.
Tarell
what is the Synthesis, properties,and applications of carbon nano chemistry
Abhijith Reply
Mostly, they use nano carbon for electronics and for materials to be strengthened.
Virgil
is Bucky paper clear?
CYNTHIA
carbon nanotubes has various application in fuel cells membrane, current research on cancer drug,and in electronics MEMS and NEMS etc
NANO
so some one know about replacing silicon atom with phosphorous in semiconductors device?
s. Reply
Yeah, it is a pain to say the least. You basically have to heat the substarte up to around 1000 degrees celcius then pass phosphene gas over top of it, which is explosive and toxic by the way, under very low pressure.
Harper
Do you know which machine is used to that process?
s.
how to fabricate graphene ink ?
SUYASH Reply
for screen printed electrodes ?
SUYASH
What is lattice structure?
s. Reply
of graphene you mean?
Ebrahim
or in general
Ebrahim
in general
s.
Graphene has a hexagonal structure
tahir
On having this app for quite a bit time, Haven't realised there's a chat room in it.
Cied
what is biological synthesis of nanoparticles
Sanket Reply
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
Privacy Information Security Software Version 1.1a
Good
Berger describes sociologists as concerned with
Mueller Reply
why and for what was five kingdom of classification of organisms introduced
SUBHIKSHA Reply
give the ans as fast as possible
SUBHIKSHA
Comment on the ozone depletion over the period of 1982 to 1996
Mpho Reply

Get the best Algebra and trigonometry course in your pocket!





Source:  OpenStax, Siyavula: life sciences grade 10. OpenStax CNX. Apr 11, 2012 Download for free at http://cnx.org/content/col11410/1.3
Google Play and the Google Play logo are trademarks of Google Inc.

Notification Switch

Would you like to follow the 'Siyavula: life sciences grade 10' conversation and receive update notifications?

Ask