Revision Mind map
Darwin
3 factors for evolution
Heritable traits
Differential reproduction
Natural selection
Variations occur when a species mutates, changes in DNA, gene flow and genetic variation
Genetic variation is necessary for natural selection because natural selection can only decrease or increase the number or frequency of alternate specie's
Darwin believed the variation of such similar finches was down to eating habits and the types of foods available to them on the islands they live in.
Species are deeply influenced by their geography. The climate of an area influence the thickness of coats and the food the animal eats as well as things like hibernation or times when they're active. The terrain, Flora and Fauna that are part of the geography, as in the native flora and fauna. This is an influence as it changes their diets and hunting techniques, it also influences the way animals fly or walk.
3 important concepts
-Natural selection
-Evolution
-Origin of species
Natural selection
One member of species is born different colour
fits environment better
The other get picked off
The more fortunate ones breed and the trait becomes more frequent
1835 galapagos island was when he made discovery
Charles collected animals and plants and made a book called origin of species
Darwin was born, 12 February 1809,he died 19 April 1882
Multicelled organisms
6 Kingdoms
Prokaryotes vs eukaryote
Single celled bacteria
Extremophiles
Sexual vs asexual
Evolution
prokaryote: a microscopic single-celled organism which has neither a distinct nucleus with a membrane nor other specialized organelles, including the bacteria and cyanobacteria.
eukaryote: an organism consisting of a cell or cells in which the genetic material is DNA in the form of chromosomes contained within a distinct nucleus. Eukaryotes include all living organisms other than the eubacteria and archaea.
6 Kingdoms of life
- Fungi
- Plants
- Bacteria
- Animals
- Protists
- Archaea
extreme lover or lover of extremes
Thermophiles, extreme heat, feed of inorganic chemicals and can survive up to 82.2 degrees in water
Pshychrophiles, extreme cold, evolved antifreeze proteins can survive -24.4 degrees water
Polyextremophiles, all extremes
Tardigrades are polyextremophiles
micro animals
Can curl into a ball and slow metabolism to survive
Single celled bacteria
Caused first mass extinction
Paved the way for complex life
Sent the first free oxygen molecules into the atmosphere
Cyanobacteria, single celled, doesn’t have nuclei
3.5 billion years ago the atmosphere was mostly nitrogen carbon dioxide and methane
Almost all oxygen was in water
Oceans populated by anaerobic microbes
They get energy by scavenging molecules
Between 3.5 and 2.5 billion yrs. Ago cyanobacteria evolved to have photosynthesis
Photosynthesis: turn carbon dioxide and water into sugars and oxygen using the power of the sun
Ancestors of cyanobacteria
Their populations exploded because they used the sun as energy when the other species had to absorb molecules
They filled the atmosphere with oxygen
At firdt iron and decomposing cells soaked up the oxygen
After a few hundred million years it filled the atmosphere
This caused mass extinction because that air was toxic to most creatures
Thinner atmospheric blanket caused first and longest ice age
Huronian glaciation
Eventually life adjusted
Endosymbiosis, one bacteria swallowed another whole
Cyanobacteria = chloroplasts
Eats, excretes, reproduces and moves as a self functioning entity
More complex
Cells within had their own purpose
Sexual reprocuction
Asexual reprocuction
Pros
Quicker, easier adaption to environment
Increases genetic variation
Faster evolution
Cons
Takes More energy
Requires finding a mate
more can go wrong
Pros
Faster
Only requires a single parent
Less energy used
Grow population faster
Cons
Problems with parent are carried in their entirety to the offspring
Less able to survive environmental change
Easily wiped out by disease
Can result in overcrowding
Evolution is "any change in the heritable traits within a population across generations"
Duplicating DNA and passing it on
DNA tells cells how to grow and function
Single cells reproduce by copying their dna, then moving it to either side of their body and splitting in two
They then grow back
sexual reproduction is when a male and female animal mate
Evolution in reproduction and dna
Errors can occur which mutate the DNA, random, accidental
With multicellular animals such as a badger, the child has half of each of it's parent's DNA, meaning it has half of each of their traits as well
That also results in evolution, as they can also mutate dna
People began to select and influence evolution with selective breeding (dogs specifically)
If you go back far enough we all share a common ancestor
The process of reproduction with variation over millions of year seems to be responsible for everything living and their diversity
Cetaeceans , whale dolphin porpoise
Evolved from ancient four legged land animal
Two claims
All living thigs on earth evolved from a commo ancestor
The volution of living things is powered by natural processes
There is evidence for both of these
Ways of checking "ancestry" of an animal
Comparative anatomy
Embryology
Found fossils blur the line between four legged land mammals and whales
Whales evolved from land creatures
DNA
In dry places, plants depend on wild grazers to till the soil withtheir feet fertilize with their waste and remove excess vegetation my eating it
How evolution works
A species is a group of animals capable of producing offspring with one another
Visual resemblance , slightly different traits and characteristics
Cells, nucleus, chromosomes , dna, genes
More offspring , more little differences
Heredity, passing on of dna to offspring
Recombination, random mixing of genes
Mutation, random DNA changes (copyig errors)caused by radiation or chemicals
Can be negative