Evolution Flashcards
(16 cards)
Variation
Continuous variation
Where characteristics can be any value in a range. Characteristics can be measured and expressed in a number
Variation
Examples of continuous variation
Height, weight, heart rate, leaf length
Variation
Variation
The existence of variety and differences with and between species
Variation
Variation between members of the same species
Intraspecific
Variation
Discontinuous variation
Where characteristics are in distinct categories
Variation
Examples of discontinuous variation
Sex, eye colour, finger prints, blood groups
Variation
Causes of genetic variation
at least 3
- Alleles-genes have diff alleles
- Mutations-changes to DNA
- Meiosis-crossing over of chromatids
- Sexual reproduction-2 different parents
- Chance-any sperm can fertilise an egg
Theory and evidence for evolution
Charles darwin
What was his theory called
Theory of evolution by means of natural selection
Theory and evidence for evolution
Examples of charles darwin’s theory
- Antibiotics-one of the main concerns with the overuse of antibiotics is that bacteria becomes resistant to it
- Peppered moth- their black + white wings were able to blend them into the leaves/trees
Theory and evidence for evolution
Palaeontology
Analysisng fossils of different organisms
Theory and evidence for evolution
Preserved animals
- In fossiled tree resin-lack of oxygen and moisture means that decomposers can’t survive there to break them down
- Glaciers too cold
- Peat bogs too acidic
Theory and evidence for evolution
Petrified fossils
- Body parts like teeth dont decay easily
- Theyre slowly replaced by minerals that form rock-like substance in same shape as original part
Theory and evidence for evolution
Trace fossils
An impression like footprints can be left in a soft material like clay
The impression stays as the clay hardens
Theory and evidence for evolution
Comparative anatomy
- Comparing anatomy of different animals
- Provides evidence of close evolutionary relashionship and indicates common ancestry
- Homologous structures- evidence of divergent evolution(body parts of diff species with similar structures but diff functions)
Theory and evidence for evolution
Comparative embryology
- Comparing anatomy of embryos
- An embryo is an unborn offspring
- All vertabraes share a basic pattern of organisation
Theory and evidence for evolution
Comparative biochemistry
- Similarities of DNA and proteins etc.
1. Comparing DNA sequences
2. Comparing protein sequences (Cytochrome C in respiration, Haemoglobin, RNA polymerase
