Module 4 Part 1 Flashcards
What is the biological species concept?
Reproductive Isolation
What did Charles Darwin Contribute
How species evolve
The idea of evolution
Who proposed fixity of species
Plato
What is fixity of species
All modern organisms are unchanged descendants of those ancestors
Small variations may occur between individuals but species remain unchanged
What did Aristotle Contribute
Views species as fixed but his observations to conclude that life forms could be arranged on a ladder of increasing complexity
Carolus Linneaus
Binomial Classification
Georges Cuvier
Study of fossils
What is a fossil?
Extinct speci that no longer exists
Any trace of an organism that lived in the past
What was Georges Cuvier known for
First to use comparative anatomy to develop a system to classify animals
The first problem relating to fixity of species
Discoveries by European Explorers
What did the European Explorers find
More diverse organisms
Example of something the European Explorers found
Unique fauna and flora in the other parts of the world
Challenged conventional idea of fixity of species
What did Georges Louis Leclerc find
Frech Naturalist
Suggested that living things do change through time
Factors of change proposed by Leclerc
Migration, Geographical Isolation, Overcrowding and struggle foe existence
Who publicly rejected that one species could evolve into another
Leclerc
Erasmus Darwin
Believed evolution has occurred
Aware that modern species were different from fossil types
Saw how plant and animal breeders used breeding practices to changes the traits of domestic species (offspring inherited features from their parents)
Did not know what caused evolution
Second reason which caused problems for the idea “fixity of species”
The fossil record
How did the fossil record helped disprove fixity of species
Differences of species were found found in different layers of the fossil
Doctrine
No species of organism had ever become extinct
Who disproves Doctrine
Cuvier
What did Cuvier find from his fossil stuff
Abrupt changes between layers
Proposed that these species were destroyed due to multiple catastrophies
Different layers contained different organisms
Did Cuvier have an answer on the appearance of the new species in the fossil record
No
Jean Baptise Lamarck
Also saw the first fossil
What did Lamrk say about fossils
Fossils show an evidence of Gradual change
Bottom layers of fossil are
Older
3 important concepts Lamark came up with his fossil shit
- New Species have appeared gradually
- All species have change ,but rate of change are unequal
- Species do not appear after they have become extinct
How did Charles Darwin propose on hoe species arose?
The process of “Descent with Modification”
Charles Darwin was a _________ to Capt. Robert FitzRoy
Companion
But become the ships naturalist later
Duties of a ship Naturalist
Recording the weather
Geological features
Animals
Fossils
Rocks
Minerals
3 key events in Darwins Voyage
- Experienced Earthquake in Chile
- Darwins observations in South America and Galapagos
- Visited Cocos(Keeling) Islands
What did Darwin experience with the Earthquake
Found that rocks lined with recent marine shells were now elevated above tide
The island of Santa Maria raised an average of 3 meters
What did Darwin read during his voyage
Principles of Geology by Charles Lyell
What did Charles Lyell Propose
Uniformitarism
What is Uniformitarism
The present is the key to the past
What did Darwin observe in South America and Galapagos
Marine Iguana v Land Iguana
Blue footed booby
Galapagos island penguins
Steamer ducks - South America
How do Steamer Ducks move
Flap their wings into the water (as well as using their feet) creating an effect like a paddle steamer
What kind of fossil collections did Darwin find
Enormous number of species now extinct
Fossil changed over time (in different soil layers), more recent fossils more similar to present day forms than the older fossils
Darwin Rheas
Two rheas
there is some sympatry
Could the two rheas perhaps have originated from a common ancestor
Darwin said species ______ slightly from place to place
Varied
Sattle Back Tortoise
Shell turned up at front: an adaptation to reach upward with their long necks for vegetation
Dome shaped tortoise
Restricted to vegetation on ground
What did Darwin say about islands with tortoise absent
Cactus grows all over the ground
What did Darwin say about islands where tortoises present
Cactus grows substantial trunks which places most fruit beyond the reach of tortoises
What diid Darwin say about the adaptation of Cactuses
Natural selection has favour cactuses
What did Darwin observe on woodpecker finches
They use twigs or cactus spines to extract insects from holes in dead tree branches
What did Darwin observe on Ground Finches
Thick and wide beaks for crushing hard seeds (Bigger the beak More crushing seed)
What did Darwin Observe on Tree finches
Grasping beaks for picking up insects
What did Darwin observe at Cocos Islands
20 spp of plant
1 spp lizard
13 spp insect
Prof. Richard Owen looked at
Fossil specimens
Rev Leonard Jenyns Looked at
Fish
Mr. Thomas Bell looked at
Reptiles
MR. John Gould
Birds
Dr. Joseph Dalton Hooker
Plants
What did Richard Owen mainly look at
Toxodon Platentis in South America
A giant Rodent
It was morphologically similar to a giant capybara
What was Toxodon Plantentis morphologically similar to
Capybara
Macrauchenia patachonica
Large mammal herbivore
Resembles a humpless camel with a short trunk but not closely related to camels or elephants
What is Macrauchenia closely related to
llama
Glypodon (1839)
Giant armadillo
What did Darwin say about Glyptodon
Armadillo evolved from the Glypodon
Floreana Birds
Bigger, darker and larger beak
What book did Darwin write
Journals at sea
What was journals at sea about
Different varieties of one specie
What were Darwins observations on mocking birds of South America
Species might chance
Different varitieies of mockingbirds on different islands
Artificial Breeding
Darwins evidence of common ancestor
Providrd evidence to Darwin that mammals shared a common ancestry
Thomas malthus
Essay on the principle of population
What did Thomas Malthus say
Human populations will outgrow food supply and individuals must compete for resources
Observation 1 of Dawins Natural Selection
For any species, population sizes would continue to increase exponentially if all individuals that are born reproduced successfully
Observation 2 of Darwins Natural Selection
Nonetheless, populations tend to remain stable in size for seasonal fluctuations
Observation 3 of Darwins Natural Selection
Resources are limited
Inference 1 of Darwins Natural Selection
Production of more individuals that the environment can support leads to a struggle for existence among individuals of a population, with only a fraction of their offspring surviving each generation
In short: Many individuals die without reproducing
Observation 4
Members of a population vary extensively in their characteristics; no individuals are exactly alike
observation 5
Much of this variation is Heritable
Inference 2
Survival depends in part on inherited traits. Individuals whose inherited traits give them high probability of surviving and reproducing in a given environment have higher fitness and are likely to leave more offspring then less fit individuals
Inference 3 of Natural Selection
This unequal ability of individuals to survive and reproduce will lead to gradual change in a population with favourable characteristics accumulating over generations
What did Alfred Russel Wallace come up with
Batesian Mimicry
Alfred Wallace was the ___________ of modern evolutionary theory
Co founder
