Darwin and Evolution (5)

Sexual Selection always favors

A. Large males

B. Ornamentation such as bright feathers in male birds

C. Traits that reduce an individual’s survival

D. Traits that increase an individual’s access to reproductive

opportunities

D

Why can’t NS fashion perfect organisms?

• • Selection can act only on existing variants

• Evolution is limited by historical constraints

• Adaptations are often compromises

• Chance, natural selection, and the environment all interact

Who was Al-Jahiz?

• created book of Animals

• Species develop new traits for survival in different environmental conditions

• Believed evolution through god’s guidance

• Animals have innate desire to live, and 'biological fitness’ is

  essential to this phenomenon

What was the main though process during Darwin’s time?

• Natural theology 

• promoted investigation of living organisms —> idea that species had changed since their creation

• geology showed Earth was very old

What is deep time?

• idea Earth formed slowly 

• out there idea at the time

What is Natural history

• Biological study of organismal form and variety in natural environments

• Aristotle began classification of living/nonliving

What is natural theology?

seeks to catalog God’s creation (for the glory of God)

What is biogeography?

world distribution of organisms

What did global exploration cause

• questions for unchanging creation

• ex: butterflies looked different in different regions of Europe —> creation may have changed

What is comparative morphology? 

• the study of the size, shape, and structure of animals, plants, and microorganisms

• External appearance

What did comparative morphology reveal?

revealed structural similarities in

“dissimilar” anatomies

What are vestigial structures?

currently useless structures

What is stratification?

• Horizontal layering of sedimentary rocks

• Different fossils in different layers

What do fossils in stratification suggest?

• Fossils suggested extinction

What is Paleobiology?

Study of ancient organisms

What is catastrophism?

• theory of fossil formation by catastrophe

• the theory that changes in the earth's crust (geographical features) during geological history have resulted chiefly from sudden violent and unusual events.

What did Jean-Baptiste Lamarck contribute?

• Species change with time and pass on changes

• Organisms respond to environment

• Hypothesized mechanisms

What mechanism for evolution did Lamarck believe in?

• incorrect mechanism

• principle of use and disuse and subsequent inheritance

• Change of time were based on inner need to the organism --> will to adapt trough time 

• ex: Giraffes could will for a longer neck

Darwin summary

• Went to school for medicine —> weak stomach —> Dad said he was a failure —> went to Theology school

• Learned taxidermy from John Edmunston —> became an abolitionist

• Didn’t release On the Origin of Species because afraid of of Social Darwinism ideas and it challenged God

What did the Giant Sloth and Giant Armadillo in South America reveal?

animals in the past are similar to modern animals

What did seashells at the top of mountaintops show Darwin?

• Evidence of marine life in mountains --> area probably once out of water and rose out

• Showed Darwin time is long

Who was Alfred Russel Wallace

• young scientist who was on the same though process as Darwin

• pushed Darwin to release The Origin of Species

How do we get different species?

Descent with modification

What is descent with modification?

principle that evolution occurs through the gradual modification of heritable traits passed from parents to offspring, leading to new species that share a common ancestor

How did the Galapagos Islands show Descent with Modification?

Fauna of Galapagos Islands: each island had similar physical conditions but distinct species of mockingbirds, tortoises, etc

What was Darwin’s belief system?

• monogenism

  • race is a socical construct —> against racial essentialism

• Polygenism: racial essentialism

• He was sexist duhh

What did Darwin’s Orchid show?

• had extremely long nectary —> must have a pollinator with a long tongue