Published on May 9, 2007
Theory of Evolution part II
Evidence for Evolution Inferences about the history of life are based on the assumptions of certain geological principles.
Nicolaus Steno (1638-1687) Steno's Law of Superposition
James Hutton (1726-1797) Uniformitarianism: “ The present is the key to the past” the fundamental principle that geological processes and natural laws now operating to modify the Earth's crust have acted in much the same manner and with essentially the same intensity throughout geologic time, and that past geologic events can be explained by forces observable today;
Charles Lyell (1797-1875) ﬁrst geologic time scale proposed an older earth than was previously accepted Lyell’s text inﬂuenced Darwin’s ideas
Relative Age generally relies on position within the geologic column in reference to index fossils. Absolute Age generally relies on the rate of decay of various radioactive isotopes.
The amount of time it takes for 1/2 of a radioactive isotope to decay to non- radioactive form is known as half-life.
Generalized presentation of Geologic time and the appearance of life forms.
The Fossil Record paleontologist- scientist who study fossils Fossils are the preserved remains or traces of once living organisms the cumulative collection of fossils represents the “Fossil Record”
The Fossil Record While there are gaps, paleontologists can oﬀer a relatively clear picture of the evolution of many organisms. tells us of major changes in climate and geography as environments changed over earth’s history, changes in living things followed
How fossils form frozen in ice trapped in hardened tree sap peat bogs, quicksand, tar pits most are found in sedimentary rock
Problems in Assembling the Fossil Information all of the fossil “puzzle pieces” are not in place many organisms may live and die without leaving a trace fossil bearing rocks must be exposed to weathering
Evidence from Living Organisms homologous structures- similar structures adapted to diﬀerent environments
Evidence from Living Organisms vestigial organs- organs or structure that seem to serve no useful purpose
Evidence from Living Organisms Structural homologies support common descent with modiﬁcations If organisms had arisen independently, there would be very little chance of these similarities Each new species adapted what was present in the species before it.
Evidence from Living Organisms similarities in embryo development with the passage of time, embryos become more dissimilar Biochemical similarities- DNA, ATP
Evidence from Living Organisms Modern Synthesis Integrates the new genetics with natural selection. Ancestral relationships (phylogeny) modeled as a branching tree. Cladistics - branching tree cladagram from comparing shared characters to derived characters
Protist Fungi Plants Archeabacteria Animals Eubacteria Common Ancestor
Provided to YouTube by The Orchard Enterprises Evolution - Part II · Oehlers · Grabowsky · Beck Lost and Found ℗ 2008 Head Records Released ...
Evolution II. 933 likes · 20 talking about this. Evolution Part II. Facebook logo. Email or Phone: Password: Keep me logged in. Forgot your password? Sign Up.
Real People, Fake Arms with Steve Carell and Justin Timberlake , Part 2 - Duration: 6:08. The Tonight Show Starring Jimmy Fallon 5,886,387 views
CREATION VS. EVOLUTION—[PART II] Previous Lessons Lesson 1 – Atheists, Agnostics, Skeptics & Infidels Lesson 2 – The Cosmological Argument (Universe)
"Evolution, Part 2"' is the twelfth episode of the seventh season of Stargate SG-1. Dr. Daniel...
The Creation Theory and the Evolution Theory are interdependent - Part II The Answer to: Where did Cain get that wife of his? Originally published on ...
The Creation Theory and the Evolution Theory are Interdependent Neither can subsist without the other Part II Plus the Answer to: Where did Cain get that ...
[EDITOR’S NOTE: Part I of this two-part series appeared in the September issue. Part II follows below and continues, without introductory comments, where ...
If you've been following this site, you'll know that yesterday I wrote a long critique of David Dobbs's recent article in Aeon magazine, an ...