Loading ...
Sorry, an error occurred while loading the content.

RE: [SACC-L] Fw: It's been one link after another... all of them missing!

Expand Messages
  • Lynch, Brian M
    This reads like it should be an article in our newsletter! Thanks, George! Brian Brian Donohue-Lynch Anthropology/Sociology Quinebaug Valley Community College
    Message 1 of 2 , May 22, 2009
      This reads like it should be an article in our newsletter!

      Thanks, George!


      Brian Donohue-Lynch


      Quinebaug Valley Community College

      Danielson, CT 06239

      (860) 412-7255


      From: SACC-L@yahoogroups.com [mailto:SACC-L@yahoogroups.com] On Behalf
      Of George Thomas
      Sent: Friday, May 22, 2009 1:40 AM
      To: sacc-l@yahoogroups.com
      Subject: [SACC-L] Fw: It's been one link after another... all of them

      How Many Times Will Paleontologists Find the "Missing Link"?The fossil
      hunter's favorite phrase.By Brian Palmer SLATE Thursday, May 21,

      A 47-million-year-old skeleton of the most complete fossil primate ever

      Scientists unveiled Tuesday the fossil of a lemurlike creature called
      "Ida" that lived 47 million years ago in what is now Germany. According
      to media reports, the discovery is a missing link in human evolution.
      The research team itself is pushing the same idea: They've just released
      a book about the fossil called The Link, and a documentary of the same
      name will air Monday on the History Channel. It seems like we're always
      hearing about these "missing links" in paleontology-what gives?
      It's shorthand for an important evolutionary discovery. The media love
      the phrase missing link-news stories have used it to describe no fewer
      than 28 paleontological discoveries in the past decade. Scientists
      sometimes substitute the phrase for the more technical-sounding
      "transitional morphologies," which refers to anatomical structures that
      bear some resemblance to both older and more recent physiology. But the
      research community tends to frown on the use of such language, and the
      discoverers of Ida have been criticized in some quarters for overselling
      their research.
      The notion of "missing links" in the fossil record predates even the
      theory of evolution. Charles Lyell, a mentor to Darwin, used it in
      1851-eight years before the publication of On the Origin of Species-to
      describe an abrupt transition in the types of fossils he found in
      adjacent layers of sediment. In 1863, a Scottish physician named John
      Crawfurd uttered the phrase for the first time as a critique of
      evolution: He demanded the missing fossil evidence to show "how a monkey
      became a man."
      While most paleontologists agree that the discoveries of Homo erectus in
      1891 and Australopithecus africanus in 1924 answered Crawfurd's charge,
      his use of the phrase to describe a common undiscovered ancestor of
      human and nonhuman primates captured the popular imagination and still
      hasn't let go. (The use of the phrase to describe the new fossil has
      ignited debate between creationists and evolutionists, though the
      discovery says nothing about man's relationship to apes.)
      Most media reports use missing link more generically. Sometimes the
      phrase implies that a fossil is the direct descendant of two or more
      extant species. Such discoveries are rarely made, however. Most fossils
      represent species that are morphologically similar to a predicted
      ancestor but not connected in a straight line to any modern species.
      Even if a fossil were a direct ancestor, a paleontologist couldn't be
      sure; all she could say is that it would be consistent with direct
      ancestry. (When a fossil record surrounding a species is unusually
      dense, as it is for humans, scientists can sometimes find predecessors
      with certainty.)

      A missing link may also describe an intermediate anatomical form that
      suggests how modern organisms might have developed certain capabilities.
      For example, an ancient fish with proto-wrists, elbows, and shoulders
      might be called a missing link between sea creatures and land animals.
      In this sense, though, every fossil is a missing link. There's no single
      intermediate point between, say, opposable and nonopposable thumbs.
      Rather, a wide variety of fossils seem to resemble both hand structures.
      No one can say which version is directly related to the two. It is
      entirely possible that all, or none, of the fossils are steps along the
      Paleontologists suspect that certain transitional structures might never
      be found due to biases in the fossil record. For example, some believe
      that the human ancestors who became bipedal were forest dwellers. If
      this were true, we may never see the hard evidence, since forests
      teeming with hungry scavengers and bacteria are usually bad environments
      for preservation.

      [Non-text portions of this message have been removed]

      [Non-text portions of this message have been removed]
    Your message has been successfully submitted and would be delivered to recipients shortly.