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.
What type of speciation did darwin base his theory on?
Phyletic speciation
What is divergent speciation?
When two or more species are produced by splitting from a single original species by migration or adaptive radiation.
Gradually each species gives rise to an independent species e.g. Darwins finches. When a population enters a new ecological zone is generally quick to produce new species by adaption to new environment
What is allopatric speciation?
Also know as geographically isolated speciation.
A geographical barrier divides the population into two smaller units such as when sea level rises and forms an island separate from the mainland or two sides of the mountain. The two separated populations evolve separately and differently
What is adaptive radiation?
Rapid speciation of a species or more than one to fill different ecological niches.
Isolated ecosystems such as mountain areas can be colonised by a species which undergoes rapid divergent evolution
Can also occur after mass extinctions
What type of radiation occurred with Galapagos finches?
Adaptive radiation.
Adaptive radiation diversified beak shapes to adapt them to different food sources.
What type of radiation did the cichlids fish undergo?
Adaptive radiation
What is co-speciation?
Two populations speciate in parallel if they live closely
Parallel phylogenic trees
Broad range and narrow range host species
It also happens between parasites and their hosts
When is reproductive isolation required?
In cladogenesis speciation
When is no reproductive isolation required?
Anagenesis speciation
What is gene flow?
Transferral of genetic material between two populations increasing genetic variation within those populations.
Gene flow can go both ways due to natural selection and random genetic drift
What is hybrid speciation?
A hybrid created by two different species which leads to a distinct phenotype.
This phenotype can be stronger than the original two species so natural selection favours these individuals
This can eventually lead to a separate species
What is random genetic drift?
By chance genes are passed on to offspring
Do species evolve only because of natural selection?
No, evolution can occur due to genetic drift This means that just by chance especially in small populations evolution can occur without specific selective pressure
What is stasis?
Stasis refers to lineages that have not changed Much over time
What is hybridisation with change in Chromosome number called?
Homoploid hybrid speciation
What is polyploid speciation?
It involves changes in chromosome number And is more common in Phenomena
Give an example of speciation by hybridisation
Mariana mallard duck and Sunflowers
What is artificial speciation ?
People manually select Desirable characteristics to reproduce in animals
What did rice and salt do?
Bread fruit fruit flies using a maze as part of artificial speciation. Eventually the offspring would not breed with each other
What did Diane Dodd Show when she bred fruit flies?
Allopatric speciation over 8 generations using maltose and starch food
Give four examples of mechanisms for cladogenesis
Peripatric, allopatric, parapatric, sympatric
What does Patric mean?
Place
What is peripatric?
Peri = near
The small population isolated at the edge of a larger population
What does allopatric mean
Geographically isolated populations
What does parapatric mean?
Continuously distributed population, only partial separation So individuals of each species may come in contact across barriers. At reduced fitness Of the hetero is zygote prevents breeding between two species
Para = besides/ adjacent but overlap.
What is sympatric?
Within the range of the ancestral population
What type of speciation is Well recorded
Anagenesis through phyletic gradualism and punctuated equilibrium
And cladogenesis as all four types have taken place
Give an example of parapatric speciation.
Mine spoil
Why do Allopatric populations evolve differently?
A. They are subjected to different selective pressures.
B. They independently undergo genetic drift
What happens when two allopatric species come back into contact?
A. The individuals become sympatric and hybridise together so the two populations again become one
B. They have evolved search that the reproductively isolated and are no longer capable of exchanging alleles. Speciation has occurred
In the absence of a geographic barrier what can encourage speciation
Reduced gene flow
Why are there so many endemic species found on islands?
Island genetics and Founder effects.
Small isolated populations tend to produce unusual traits
What is the main mechanism of speciation?
Allopatric
Give an example of Allopatric species
Darwins finches
Examples of post zygotic barriers
- animal dies before birth
- animal is born but sterile
Examples of prezygotic reproductive barriers
Temporal isolation, habitat isolation, behavioural isolation, mechanical isolation, gametic isolation,
What is gametic isolation?
Sperm of one species cannot fertilise the egg of another species
What is a temporal barrier?
Species mate at different times in the day, different seasons or years
What are the 3 domains of life?
Eukaryotic, bacteria, archaea
How would you define a prokaryotic cell?
It is simpler and smaller than a eukaryotic cell, it doesn’t contain a nucleus or other membrane enclosed organelles.
How would you define a eukaryotic cell?
It has membrane enclosed organelles, the largest is the nucleus
What type of organisms are eukaryotes?
Membrane bound nucleus
What are Protista?
Single called organisms
What is heterotrophic?
Feeding by absorption
What does autotrophic mean?
Feeding through photosynthesis
Are morphologically similar marsupials closely related to non marsupial animals that look similar to them?
No, eutherian mouse more closely related to whale than marsupial mouse
Give an example of convergent evolution
Octopus eye and vertebrate eye
What is dichotomous branching?
Branching pattern found in plants
What is a dichotomous key?
A yes no flow chart like series of questions about the morphology of an animal to identify it
What is homology?
Shared ancestry between two species
Similar morphological features with different functions such as the wings of birds and bats and forelimbs of humans, whales, lizards and birds
What is analogy?
Morphological structures have similar functions but different evolutionary origins
E.g. Wings in birds and insect wings
What is convergent evolution?
Unrelated organisms independently evolve similar traits due to adapting to similar environments
What determines the pace of macro Evolution?
Whether the great differences that distinguish higher tax a have gradually arisen or discontinuously risen
What are the mechanisms by which novel features have come into existence?
Whether or not there are grand trends of any kind
What is phyletic gradualism?
Evolution occurs uniformly
Anagenesis
The steady and gradual transformation of lineages
What is punctuated equilibrium?
Most sexually reproducing species will show little to no evolutionary change throughout their history and when evolution does occur it happens sporadically through cladogenesis
Is macro evolution reducible to micro Evolution?
Is micro evolution distinct from macro evolution
Some examples of macro evolution are best considered as the result of the sum total of micro evolutionary processes.
What is the study of trilobites by Sheldon a good example of?
Evidence of gradual evolution
What type of speciation occurs after mass extinction ?
Adaptive radiation
What is the difference between cladogenesis and divergent speciation?
Divergent speciation occurs through migration and adaptive radiation.
Cladogenesis occurs through reproductive isolation
Gene flow can go both ways because ?
Random genetic drift and Natural selection
What is phyletic speciation also known as ?
Anagenisis
What’s phylum Does the jellyfish come under?
Cnidaria
What is the Biology field that studies the classification of living beings
Taxonomy
List the correct order That living beings classified into
kingdom, phylum, class, order, family, genus and species
What is meant by binomial nomenclature and what Are its Basic rules
Scientific nomenclature of a species must have, at least, two names: one that classifies it as genus and the other that identifies it as species. The name related to genus is the first and must begin in uppercase, the other following names must be written in lowercase. Besides this rule, scientific names of species must stand out and be written either in italics or underlined or still bolded or between quotation marks.
Which beings form the kingdom Protista
protozoans and algae
What are some representatives of the echinoderm phylum?
Sea urchins, sea cucumbers
Give some examples of species under the phylum Cnidaria
Jellyfish, hydra, corals and sea anemones
what species is part of the phylum Platyhelminthes
Flatworm
What is the two typical morphological features of nematodes that differentiates them from platyhelminthes?
Nematodes are round and they have complete digestive systems
What is the only three phylums to have a complete digestive system ?
Nematoid worm and annelid worm and mollusc
What is the difference between a Nematoda and an annelid worm
Annelids have segmented bodies, nematodes don’t
What are some examples of annelids ?
Earthworms, leeches and lugworms.
Give some examples of species in the phylum mollusca
Snails, octopuses, squids and oysters
Bacteria shapes
Rod – bacilli
– Sphere – cocci – Spiral – spirilla
Describe the parts of a virus and what does it inject?
Head, body, tails
What type of disease is scrapie?
Prions disease
What are the microbial growth phases
Lag(first horizontal line), log (rise in growth), stationary phase (flatline St the top of the graph), death (declining part)
What is a choanocyte?
Also known as collar cells, they line the interior of the as onion, synopsis and leu onion body type sponges that contain a central flagellum or undulipodia and they make up choanoderm which is a type of cell layer found in sponges
What is a choanoblast?
One of several cellular elements within the syncytial tissue of a heatinellid sponge, choanoblasts bear flagellated extensions called collar bodies
