fossil successionArgument #1 for Common Descent
fossils: case for What are fossils? Mineralized remains or impressions of organisms that lived in the past. Where are they found? All over the Earth, and at times many are found in the same location.
fossils: case for Darwin thought the sequence of fossil forms that are found in sedimentary rocks supported his idea of common descent. Why? When you dig deep into the Earth you notice that there is layering or strata. In general, the further you go down, the older the rocks are. Sometimes, different fossils are found in different layers. Some strata contain no fossils at all.
fossils: case for In one there may be a sponge, another a trilobite, the next a frog and then maybe a horse. Darwin’s thought was that life had changed over the course of history and that these changes made a distinct pattern. He saw that species would appear and then disappear in the rock layerings. He called this “geological succession”. Today we refer to it as “fossil succession”. Darwin also noticed that over time, the fossil record went from more simple organisms to more complex.
fossils: case forbranching pattern What led Darwin to think that he could just connect the dots? In order for the branching tree diagram to be accurate, there must be “in between” forms that existed between one branch and another. en Today, in-between forms are referred to as e w s “intermediate” or “transitional” forms. et m -b or in f Evolutionary biologist say that such forms have been found.
fossils: case forbranching pattern An example evolutionary biologists would point to, is called “mammal-like reptiles”. They appeared 200-300 mya. They are extict, and have mostly reptilian traits, mixed with some mammalian features. A more recent discovery was a transitional fossil connecting land-dwelling mammals to whales.
fossils: case forbranching pattern Paleontologists see that there are gaps still in the fossil record. Typical evolutionary trees represent these gaps as dotted lines -- pieces still to be found. Advocates for Common Descent, argue that the gaps that have been ﬁlled make it reasonable to assume that we’ll eventually ﬁnd the rest.
fossils: case foronline resourcesArguments for Evolutionhttp://evolution.berkeley.edu/evolibrary/article/0_0_0/lines_02http://biologos.org/questions/fossil-recordhttp://www.nap.edu/openbook.php?record_id=6024&page=15http://bioweb.cs.earlham.edu/9-12/evolution/index.htmlhttp://www.pbs.org/wgbh/nova/evolution/fossil-evidence.htmlCounter Arguments against ID:http://www.millerandlevine.com/km/evol/wells-april-2002.html (Ken Miller - speaking against arguments that ID has made - Cambrian Explostion)
fossils: a reply Most critics would agree that the fossil record shows change over time. They also agree that, in general (but not always), more complex forms are found higher up the strata. But overall, they say that the pattern of fossil evidence contradicts the neo-Darwinian picture of evolution, in 2 ways. the abrupt appearance of the fossils the stability of animal forms during their time on the Earth
fossils: a reply Paleontologists have discovered that new life forms have appeared, not in a gradual manner, but very abruptly. 530 million years ago, more than half of the major animal groups (phyla) appeared suddenly. This was during the Cambrian period. Scientists now refer to this sudden and dramatic appearance as “the Cambrian Explosion”.
fossils: a replyall of a sudden The Cambrian Period is a fairly short period of time in relation to the rest of the Earth’s history. Evolutionary biologists doubt that it was enough time for the slow, gradual Darwinian proesses to produce the amount of change that occurs in the Cambrian Explosion. Many scientists think the sudden appearance of many new life forms contradicts Darwin’s prediction that new forms would emerge gradually over a great period of time.
fossils: a replyall of a sudden A similar event took place during the Paleocene epoch (65-55 mya). 15 new mammalian orders suddenly entered the fossil record. This is referred to as the “mammalian radiation”. How different are these mammalian orders? A few examples of animals from different orders are: bears, bats, horses. They are quite different.
fossils: a replyall of a sudden The ﬁrst bat appears during the Eocene epoch. It is clearly a bat, that is capable of ﬂight. Yet, there is nothing that resembles a bat prior to that. Critics of fossil succesion also argue that this is true within plants.
fossils: a replyall of a sudden Critics say the pattern of fossil appearance does not support Darwin’s picture of a branching tree. It more so gives a picture of independent beginnings. Darwin once said that the pattern of abrupt appearance, “may be truly urged as a valid argument” against his theory of Common Descent.
fossils: a replyall of a sudden Fossil studies are showing that most animal forms remain the same for their entire life on Earth. Paleontologist David Raup says, “Instead of ﬁnding the gradual unfolding of life what geologists of Darwin’s time, and geologists of the present day actually ﬁnd is a highly uneven or jerky record; that is, specis appear in the sequence very suddenly, show little or no change during their existence in the record, then abruptly go out of the record.”
fossils: a replya summary The sudden appearance of new forms of life and the stability of these form over time have led some scientists to doubt that the fossil record supports the case for Common Descent.
fossils: a replywhat about transitional fossils? Let’s think ﬁrst about a student who only gets 3 questions correct on a test with 100. If that student went to the teacher and said, “Look at these 3 answers, they are correct. This proves that I understand the concept. It’s just a ﬂuke that I got the others wrong.” What would the teacher say? “You’re crazy! It was probably a ﬂuke that you got 3 correct.”
fossils: a replywhat about transitional fossils? In the same way, critics would say that discontinuity is the prevailing pattern in the fossil record. The transitional forms are rare exceptions. They would argue that Darwin’s theory has failed an important test. Just like you are tested by “celebrations of learning”, theories are tested by how well they match the evidence. In a majority of cases, Common Descent does not match the evidence of the fossil record.
fossils: a replyresources Evolution Exposed by Roger Patterson Speciation - page 57-67 Homology - page 68-72 Fossils (transitional) - page 73-74 Molecular Homology - page 74-75 Embryology - page 95-96 Refuting Evolution by Jonathan Sarfati The Politically Incorrect Guide to Darwinism and Intelligent Design by Jonathan Wells