Evolution of Life Flashcards
(135 cards)
Who was Plato? 427 - 347 cb
He was a philosopher who believed all life forms represent an imperfect replica of their heavenly forms and any variation of plant/ animal was an imperfection
How many um in a millimetre?
How many um in a nanometer?
How many nm in a mm?
1000um in a mm
1000nm in a um
1 million nm in a millimetre
What is genetic variation?
Where each population has a wide range of alleles that control their characteristics
What does macro evolution refer to?
Change at or above the species level, at least the splitting of one species into two or more daughter species.
What is micro Evolution?
Change below the species level
What 4 reasons cause micro Evolution?
Migration, populations, development, genetics
What 3 reasons cause macro Evolution?
Species selection, historical constraints/ developmental constraints, independent evolution (vicariance)
What does micro evolution refer to?
- changes within the frequency of alleles within a population or species
- their effects on phenotype of organisms that make up that population or species
- can also apply to changes within species which aren’t genetic
Differences between micro and macro evolution?
Micro - species stay the same
Macro - new species are created
Define a species
A group of individuals that potentially or actually interbreed in nature, the biggest gene pool possible under natural conditions.
What does diversification =?
Speciation vs extinction
What does speciation vs extinction create?
Diversification
What did Darwin NOT explain?
- how genetic traits were inherited
- the source of variation
- how life on Earth originated
What was the Pasteur experiment in 1860?
Made by Pasteur.
He disproved spontaneous life generation using vials of broth with different types of tubes on the ends, in the longer tube bacteria got stuck and couldn’t reach the broth to reproduce leaving it untouched in which wouldn’t be able to happen of spontaneous generation was true.
Who was Francisco Reid 1688?
Who’s work was similar to his and what was the key difference between the two experiments?
He created an earlier version of pasteurs experiment.
He disproved spontaneous generation in sealed flasks but EXCLUDED air which left the topic up for debate unlike Pasteurs experiment.
Who came up with the 5 parts of natural selection?
What are the 5 parts?
Charles Darwin
- Variation
- Heritability
- Overproduction
- Reproductive advantage
- Change/ time
What is lineage?
Line of descent of a species through time.
What is a phylogenetic tree?
Shows evolutionary relationships between species that share similar ancestry
Also known as cladogram
Extinction through speciation….
True or false?
True.
Speciation is where a population becomes so different they can no longer interbreed and the old species dies out.
E.g. Isolation speciation where two species become geographically isolated and evolve differently
What is speciation?
The origination of a new species through evolution
Who came up with ‘I think’ and what is it?
Charles Darwin.
Tree of life; a metaphor to describe relationships between organisms designed to express the concept of the branching divergence of populations and then species from ancestors it is now Known as a phylogenic tree.
On a phylogenic tree what points and splits describe significant and insignificant events?
Rapid change speciation event is a flat split into two.
Little change in phenotype is a vertical line on a phylogenic tree
Dead ends on a tree are extinction events
Gradual change phenotype is a diagonal line on a phylogenic tree.
Give an example of a ring species?
Ensatina salamanders or lesser backed gulls
Who was theodosius dobshanky? 1900-1975
Synthesis of genetics and evolution
Mutation as the source of variation