Textbook Notes (367,974)
Canada (161,538)
Biology (310)
BIOL 359 (43)
Chapter 2

Chapter 2.docx

3 Pages
138 Views
Unlock Document

Department
Biology
Course
BIOL 359
Professor
Jonathan Witt
Semester
Winter

Description
BIOL359 - Evolution Winter 2013 Chapter 2: The Pattern of Evolution - Theory of Special Creations o Species are immutable, independent & recent - Darwin’s Theory of Evolution o Species are not immutable, but changes through time o Species are derived not independently, but from common/shared ancestor o Earth and life are more than 6,000 years old 2.1. Evidence of Change through Time - Theory of Special Creation: Species, once created, are immutable - Evidence from Living Species o Microevolution: Small scale changes (monitor natural populations)  E.g. Soapberry bugs evolved shorter beaks o Macroevolution: Dramatic change (monitor bodies of living organisms)  E.g. Birds evolved from dinosaurs o Direct Observation of Change through Time  Soapberry bugs, uses long beaks to penetrate the inflated balloon like fruit capsules on their host plants(Balloon vine) to reach the seeds  After the import of the flat-podded golden rain tree, soapberry bugs began to exploit it  The lengths of the bugs’ beaks was much shorter for bugs living on flat-capsuled host than round-capsuled hosts (short-beaked bugs are descendants of long-beaked bugs)  The bug from balloon vine developed long beaks regardless, same for the bugs from golden rain trees (The 2 populations are genetically different)  The characteristics of soapberry bugs are not immutable, but changed over time o Vestigial Organs: A useless version of a body part  Vestigial structures  Humans tiny bone “coccyx” – Descendants of ancestors with tails  Arrector pili muscles attaching to hair – Descendants of ancestors with hair  Vestigial developmental trait  Chickens have 3 forelimbs & 4 hindlimbs, but during development, there’s 4 forelimbs & 5 hindlimbs – Extra digit later disappears  Vestigial genes:  Humans’ gene for encoding enzyme CMAH on chromosome 6, disabled by a 92 bps deletion (CMAH produced in abundance in other mammals) o CMAH converts an acidic sugar into surface cell displays  Humans & chimps are immune to each other’s malaria parasites - Evidence from Fossil Record o Fossil: Trace of any organism in the past  fossil record o Fossil record: Total collection of fossils worldwide o The Facts of Extinction: Extinct animals are relatives of living organisms, this is evident that Earth’s flora and fauna have changed through time o The Law of Succession: The resemblance between living and fossil forms in the same region suggests that living organisms are descended with modification from earlier species living in the same region o Transitional Forms: Species showing a mix of features, traits of ancestral population & novel traits seen from later descendants  E.g. Archaeopteryx (Crow sized, 145-150 million years ago)  Contains feathers, teeth, 3-clawed hands & long bony tail  E.g. Sinosauropteryx prima, Caudipteryx zoui & Microraptor gui – long feathers  E.g. Whales with vestigial pelvis & leg bones BIOL359 - Evolution Winter 2013 Box 2.1. A brief history of ideas on evolution - The Origin of Species by Means of Natural Selection (1859) – Charles Darwin o To provide evidence on the fact of evolution o To identify natural selection as the mechanism responsible - The Fact of Evolution o It was Darwin that convinced the scientific community that Earth’s species are the products of descent with modification from a common ancestor o Darwin worked on The Origin of Species for 20+ years o The presentation of evidence of evolution was persuasive, and was accepted within a decade of publication o The mechanism of evolution by natural selection however, was not well accepted - The Mechanism of Evolution o Alfred Russel Wallace independently discovered natural selection before Darwin o Lamarck’s theory was widely accepted until the 1930s, where natural selection became popular o Gregor Mendel’s work on the mechanism of inheritance, rediscovered in 1900, lead to the development of population genetics, which merged with natural selection “combination is used to explain gradual evolution” o Genetics and the Origin of Species – 1937 2.2. Evidence of Common Ancestry - Phylogenetic/Evolutionary tree: Visual representation of descents with modification from a common ancestor - Ring Species: Documentation for common ancestry, where one common ancestor splits into 2 species with space & time o Phylloscopus trochiloides @ Tibetan Plateau, interbreeds freely unless the northeastern form encounters the northwestern form  Too much expansion over many generations “sufficiently modified” - Homology: Likeness “fundamental similarities” between species o Structural & Developmental Homology: Organisms show curious similariti
More Less

Related notes for BIOL 359

Log In


OR

Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


OR

By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.


Submit