B4 EVOLUTION Flashcards
binomial naming
two-part names, first part= genus, second part = species.
written in italics
home sapiens
our species. evolved about 200,000 years ago. skull volume 1450cm3
ardipithecus ramidus
aka “ardi”. 4.4 million years ago, walked upright and climbed trees 350cm3 skull volume
australopithecus afarensis
aka Lucy 3.2 million years ago walked upright , skull volume 400cm3
homo habillis
2.4-1.4 million years ago walked upright skull volume 5-600cm3
8homo erectus
1.8 to 0.5 million years ago, walked upright skull volume 850cm3
fossil evidence
many fossils have been found showing a gradual transition from ‘ape-like’ to ‘human-like’
stone tool evidence
older stone tools are simpler requiring less intelligence to make, younger stone tools are more complex requiring more intelligence to make
the leakeys
mary and Louis discovered homo Habilis, their son Richard worked on homo Erectus
Charles Darwin
developed the theory of evolution
evolution
the way that species develop by gradual changes over many generations due to natural selection
variation
natural differences between members of a species that affect the chance survival
mutations and evolution
changes in DNA cause variation
environmental change
change to factors such as food supply , climate or predictors
competition
the fight to eat, survive and breed
natural selection
organisms with the best genes and characteristics are more likely to survive , breed and pass on their better genes
inheritance
gaining your genes from your parents
well adapted
an organism has features that make it better able to survive and breed
evolution and the individual
an individual does not evolve during its lifetime , populations of organisms evolve over many lifetimes
human evolution
humans did not evolve from chimpanzees, we both evolved from a common ancestor
resistance
the natural ability of some members of a species to survive poisons that would kill the other members
evolution of resistance
evolution of organisms that stops them from being affected by poisons
rats and warfarin resistance
warfarin is used to kill rats some rats were naturally resistant , survived the warfarin , bred and passed on their resistance genes
antibiotic resistance
antibiotics are used to kill bacteria some bacteria were naturally resistance , survived the antibiotics , bred and passed on their resistance genes
the problems of resistance
antibiotic resistance means that many infections that used to be simple to treat may become too resistant to treat may become too resistance to treat, causing major health problems
carl linnaeus
developed the modern system of classification
how to classify
based on similarities , group things into smaller and smaller groups with fewer and fewer similarities
problems with classification
sometimes organisms that looks similar are not actually related
kingdoms
old idea, classifying living things into five kingdoms (including plants, animals, and fungi)
carl woese
developed the modern system of classification with three domains
domains
modern idea of classifying living things into three main groups , bacteria, archae, eukarya
bacteria
single celled organisms with no nucleus but unused sections of DNA
archae
single celled organisms with no nucleus but with unused sections of DNA. includes plants, animals, fungi and protists
eukarya
multi-cellular organisms with a nucleus and unused sections of DNA includes plants, animals, fungi and protists
artificial selection
when humans (normally farmers) select the animals/plants to breed with the best characteristics
selective breeding
developing new breeds of plants or animals with better characteristics by selective breeding over many generations
selective breeding in practice
choose parens with the best characteristics , breed them together , choose from their offspring with the best characteristics, breed them together , repeat from many generations
genetic engineering
changing the characteristics of organisms by giving them genes from another organism
GMO
Genetically modified organism : an organism that has its genes changed
bt corn
corn containing a gene from bacillus thuringiensis that makes it produce a substance called bt which kills insects
medical GMOS
GM bacteria are used to make insulin (for diabetes) and some antibiotics
pros and cons of GM
quicker then selective breeding and can introduce more different characteristics but is expensive
over selection
farmers focussing too much on breeding for one characteristics (such as chicken breast size), don’t spot problems with other characteristics (such as weak leg bones) causing suffering
gene leaking
the concern GMOS could breed with wild relatives, enabling the modified genes to escape into the wild. this could have ecological impacts
resistance
the concern that in areas growing bt corn, insects simply evolve resistance to bt
insulin
insulin made by GM bacteria is not identical to human insulin, and some people suffer bad reactions to it
plasmid DNA
small loops of DNA containing a few genes
restriction enzyme
enzymes that cut DNA, leaving sticky ends at each end of the piece of DNA
sticky end
a short sequence of unpaired bases at the end of a piece of DNA
ligase
an enzyme that joins two pieces of DNA by matching up that bases on their sticky ends
recombinant DNA
DNA produced by combining together two or more pieces of DNA
how to genetically engineer bacteria
cut out gene using restriction enzymes, remove plaids from bacteria and open with restriction enzymes, use ligase to join gene and plasmid together , return plasmas to bacteria
