module 4 (part 1) Flashcards
(25 cards)
what is a species?
idea of evolution came from who
charles darwin “the mystery of mysteries”
Sir John Herchel
philosopher
Early Ideas on the origin of life
-stronly influenced by religion and philosophy
-a supernatural god created each type of organism at the beginning of time
-all modern organisms are unchanged descendants of their ancestors
Who said “Fixity of species”
Plato
-all modern organisms are unchanged descendants of their ancestors
Who else veiwed “Fixity of species”?
Aristotle
he viewed species as fixed
and changes were just imperfections
how long was “FIxity of Species” belived
2000 years
until 18-19 century
Carolus Linneaus
binomial classification
Georges Cuvier
father of palentology
father of fossils (wrote a paper on Irish Elk)
what is a fossil
any trace of that an organism has lived in the past
extinct species
no longer exist
fossil record
all fossils found and described in the scientific literature
the docturine saif that no organism had ever become extinct but Cuvier proved it wrong later
What is some evidence of “Fixity of Species”?
Napoleons army raided tombs and found mummified animals that they sent to paris
dissections showed the cats were identical to modern cats, but this was only a time frame of 1000 years. evolution takes longer
but there was an idea that earth was only 6000 years old, so the time frame matched the teachings
Late 1700’s which small group of naturalists began to quietly suggest species arent “Fixed”?
a. George-Louis Leclerc
b. Erasmus Darwin
c. Jean-Baptist Lamarck
why did the small group question “Fixity of species”?
there were so many diverse fauna and flora in other parts of the world
Georges-Louis Leclerc:
-noticed too many factors of change like migration, geographical isolation, overcrowding, struggle for existance
-he rejected the idea of evolution, but low-key looked into it on Volume 44 of natural history book
Erasmus Darwin:
-poet/amature scientist
-believed that evolution had occured
-he was aware that modern species werwe different from fossils
-but didnt know the cause of evolution
Jean-baptist Lamarck:
-french zoologist
-intimate relation between variation and evolution
-realized that organisms aquired traits that were passed down
Baron Georges Cuvier
founder of palentology
-found specie fossils that dont exist today
-proposed that they were killed off by multipul catastrophies (extinctions)(noas arc)
-different layers has different organisms that were in order, not random
-But he had no real explaination for this
Charles Darwin
our ideas today on evolution come from Charels Darwin
*proposed millions of yrs ago species arose from pre-existing species by process of “decent with morphication”
-he was a “Companion” on the 5 year voyage on the BEAGLE around the world and became the “Naturalist” later (Syms Convington became his notetaker.
His GOALS on the trip:
1. investigate geology and marine invertebrates
2. collect species new to science
WHAT HAPPENED?
- earth quake in Santa Maria (CHILE) reveled layers of fossils. Darwin remembered what Charels Lyell said, earth is millions of years old. So there was time for evolution
- -DARWIN found that there was lots of diversity. He comapired marine iguanas and horned frog to land iguanas, blue-footed boobies, galapagos penguins, streamer ducks, and many more.
-HE found many fossils that suggested extinction, and the changes in fossils over time. The Greater Rhea and Lesser Rhea were similar. He questioned if they could have decended from the same common ancestor
-HE found 15 races of turtles
Suttle back (curved shell) and Dome Shape
Darwin thought that variation was key
-HE found finches that had different abilites too - *visited COCOS (keeling) Islands
- 20 spp. of plants
- 1 spp of lizard
- no land birds here or native mammals
- 13 spp of insects (1 bettle)
HE RETURNS HOME–> everyones the bird fossils esspicially will help develope their theories
Uniformitarism
proposed by James Hutton and promoted by Charels Lyell
“the present is the key to the past”
- law of physics and chemistry remain the smae
- natural processes which acted in the past will continue to act (biology contiues to change)
Charles Lyell argued against the Church saying the earth is millions of year old!
Prof. Richard Owen
Owen used Charles Darwins info to identify 3 animals
- Toxodon platensis
- earilest evidence of an extinct hoof animal
- resembled a giant Capybara - Macrauchenia patachonica
- feet resembled rhino
-morphologically similar to llama
-no living relatives (belongs to extinct group) - Glyptodon
- giant armadillo
- raised the question: if created seperatly, why would both living and extinct forms be restricted to the same area?
Darwin - it made more sense that one arose from the other (armadillo evolved from Glypotdon)
John Gould
found that Darwins Birds he brough back were all differnt species of mockingbird
*there was a different type for wach island
*this was evidnece for a common ancestor
Malthus
theory that human population will outgrow food supply: people die and compete for resources (the weak die)
this teory helped darwin realize that the adaptations of the mockingbirds helped the strong survive: called it: “natural selection among Variant offspring”
Keys to darwins theory of “Natural Selection”
Observation 1 - for any species, population size would increase exponentailly.
Observation 2 - notheless, populations tend to remain stabel in size, except seasonal fluctuations
Observation 3 - resources are limited
**Inference: too many means harder to survive
Observation 4 - members of a population vary intheir characteristics
Observation 5 - much of this variation is heritable
**Inference 2 - survival depends to the inherited traits
**Inference 3 - the ones without the good traits will die, leading to gradual changes summing over generations
who was Alfred Russel Wallace and what was in his letter?
agreed with Darwins theory, so Drawin published “The Origin of species by means of Natural Selection”
The book went against all religion so Darwin got lots of Hate.
Thomas Henry Huxley Defended Darwin because he thought his ideas were compelling
Darwins theory was accepted 1860s and universally accepted 1940s
difference between Batesian mimicry and Mullerian mimicry
Batesian mimicry - edible food looks non-edible
mullerian mimicry - color to avoid preditors
