Evolution of Life Flashcards
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
Who was Charles Lyell? 1797-1875
He was a geologist who influenced Darwin.
He showed that Earth was older than 6000 years old, as mountains built and eroded over long periods of time.
Who was Jean baptist lamark? 1744-1829?
- inheritance of acquired characteristics.
- evolution of organisms in response to felt needs e.g. Giraffes evolved longer necks as a felt need to stretch to reach the tallest trees for leaves.
Who was Aristotle? 384-322
He didn’t believe in evolution but believed in spontaneous generation which was later disproved by pasteurs experiment.
Who was Anton von Leeuwenhoek? 1632-1723
Invented the microscope which meant we could see microorganisms for the first time
Who was John Ray? 1628-1705
- father of natural history in Britain
- related form to function adaptation to environment
- looked at behaviour and physiology
- reluctant to accept extinction believed that fossilised animals were still alive elsewhere in the world.
How do you calculate microscope magnification?
Eye piece lens is always 10.
So eyepiece x objective (x10, x40, X4) = magnification.
So 10 x 40 = x400 magnification
Put the life cycle of a fern in order
- The sperm and the egg (haploid) create the zygote which is diploid
- Zygote develops into embryo
- Out of the archegonium grows the new sporophyte
- New sporophyte turns into mature sporophyte
- Under the fronds (leaves) of the mature fern are sporangium ( a group of sporangium are called sorus)
- Sporangium produce the spores through meiosis
- Spores are released into the environment and grow into young gametophyte
- Young gametophyte matures
- Mature gametophytes are hermaphrodites
- Half becomes the male antheridium producing sperm and half are the female archegonium producing eggs.
What is the female part of the fern?
Archegonium
Which half of the fern life cycle is haploid? Which half is diploid?
Haploid: gametophyte generation
Diploid: sporophyte generation
What is mitosis?
A cell splits to create two identical copies of the original cell
What is meiosis?
Cells split to form new cells with half the usual number of chromosomes to produce gametes for sexual reproduction.
Does a fern use meiosis or mitosis to produce spores?
Meiosis
Which part of a fern is photosynthetic?
The mature sporophyte
Which part of a moss is photo synthetic?
The mature gametophyte
What is the dominant part of the life cycle for a fern?
The sporophyte
What is the male part of the fern mature gametophyte?
Antheridium
Differences between moss and fern life cycle
- dominant generation is sporophyte in fern, gametophyte in moss.
- moss is non vascular, fern is vascular
Similarities between fern and moss life cycle
Both seedless spores
What is vascular?
Tissue that carries water and nutrients throughout the plant
Describe in order the moss life cycle
- Fertilisation - within the archegonium
- Egg and sperm are haploid coming together to form the zygote which is diploid.
- Everything after fertilisation is diploid.
- Zygote to embryo
- Embryo to young sporophyte
- Sporangium creates haploid spores through meiosis
- Some spores become more archegonium to produce eggs by mitosis NOT meiosis
- Some spores become antheridium to produce sperm by mitosis NOT meiosis
How do you get from haploid to diploid?
Fertilisation
How do you get from diploid to haploid?
Meiosis
What is an ecological equivalent and give an example of an animal
Example penguins and auks
Ecological equivalents are two similar species found at different ends of the hemisphere or on different continents
What do ecological equivalents demonstrate?
That energetic relationships in ecosystems have an important influence on ecological niches and the evolution of the species that live there
Examples of reproductive isolating mechanisms
-prezygotic and post zygotic isolation
Examples of prezygotic isolation
Ecological, seasonal, ethnological, physiological, mechanical, gametic mortality
Examples of post zygotic isolation
Cytology all, zygotic mortality, hybrid inviability, hybrid sterility, hybrid breakdown
What is anagenesis?
Evolutionary change in one species along a single lineage over time
What is cladogenesis?
Evolutionary divergence of one species along single lineage over time to become two or more new species
What is phyletic speciation?
Gradual change of one species over time until it becomes a new species. E.g. Horse ancestor to horse.