evolution Flashcards
(24 cards)
what is evolution?
a change in the INHERITED CHARACTERISTICS of a population over time
a change in the INHERITED CHARACTERISTICS of a population over time - what is the PROCESS?
natural selection
what is the theory of natural selection?
all living species have evolved from simple forms of life - over 3 billion years ago
when are 2 new SPECIES formed?
when 2 populations can no longer interbreed to produce FERTILE offspring
give 5 peiced if evidence for evolution:
-fossils
-geographic distribution of species
-similar HOMOLUGUS structures
-similarities in early development(embryo)
-similarities in DNA
what was Charles Darwin’s theory?
theory of evolution by natural selection
name 5 things his theeory included?
- wide range of VARIATION of characteristics
-MUTATIONS can also create variations
-individuals w characteristics most suited to environment = most likely to survive (SURVIVAL OF THE FITTEST)
-beneficial characteristics passed on to next generation
-beneficial alleles are passed on to off spring
what was Darwin’s book called?
The Origin of Species (1859)
why was there contraversy around his theory of evolution by natural selection?
- challenged the idea that God made all plants and animals
-there was insufficient evidence at the time
-inheritance of DNA was not discovered till 50years after
what was Lamarcks theory?
(not an accuarte theory)
- species evolve to achieve “aquired characteristics” in order to survive
-these “aquired characteristics” are passed on to offspring
what is a fossil?
‘remains’ of organisms from millions of years ago (found in rocks)
explain 3 ways fossils are formed:
- parts of organism REPLACED by minerals as they decay
2.casts impressions = footprints etc in clay which hardens
3.PRESEVATION - NO DECAY happens e.g trapped in AMBER OR TAR = no oxygen & moisture decay microbes die
what do fossils tell us?
- how species have EVOLVED/CHANGED
-gives info about extinct species
many forms of early life were SOFT BODIED, why do we have very few traces of them?
- been destroyed by geological activity
where did Darwin collect his evidence and what was his best speciies?
Galapagos islands
Finches
how can antibiotic-resistant bacteria occur?
give 4
- in all populations including bacteria there is VARIATION
- MUTATIONS (natural/spontaneously)
- MUTATUTIONS in pathogenic bacteria = produces NEW STRAINS of bacteria
- some strains may become RESTITTANT to antibiotics
explain the method how antibiotic-resistant bacteria can survive and spread?
- when a patient takes a specific antibiotic = will kill specific bacteria
- antibiotic resitant bacteria are not killed
= they survive and reproduce - there is less competition so will reproduce quickly/sucessfully
- population of the antibiotic resistant bacteria RISE
- then start to spread to other uninfected people
ANTIBIOTIC-RESISTANT STRAIN will spread further as there is no effective treatment
what is methicillin
a specific antibiotic
what is staphylococcus aureus?
a species of BACTERIA whic can cause fatal wound infections
what is the most commone antibiotic resistant stain called?
MRSA - Methicillin- resistant Staphylococcus aureus
give 4 causes of antibiotic resistance:
- doctors over prescribing antibiotics (to people who dont need it)
- unnecessary antibiotics used in agriculture (farming)
- poor hygiene and sanatation
- patients not finishing their course of antibiotics
give 3 ways to decrease the develpoment of antibiotic resistant strain?
- patients completing their course of antibiotics
- use of antibiotics in agriculture restricted
- doctors should not prescribe antibiotics inappropiatly
what is extinsion
no remaining individuals of a species are alive
name 5 factors which cause extision?
- changes to the enviroment e.g climate change
- new predators
- new diseases
- new more sucessful competitors
- a signle catastrophic event
