Speciation Flashcards
What conditions must be present for evolution to occur?
~ variation (differences in individuals)
~ heredity (these differences must be heritable)
~ means of selection —> must be a mechanism/pressure favouring certain variables
Describe process of natural selection/speciation
1 - Variation caused by random mutation
2 - Adaptation to selection pressures, favours certain alleles + creates competition
3 - Individuals with advantageous alleles survive and reproduce
4 - Alleles passed to offspring
5 - Changes in allele frequency
Speciation
6 - Allele frequency changes so genetic drift occurs
7 - 2 different gene pools
8 - formation of new species, can no longer interbreed to produce fertile offspring
Describe difference between two types of speciation
Allopatric —> occurs due to geographical isolation; diff selection pressures change allele frequency
Sympatric —> occurs due to reproductive isolation; changes due to variation including seasonal, mechanical or behavioural prevent two groups from reproducing
Describe general evidence supporting evolution
Fossil records —> show evidence for transitional species, showing how one species could evolve into another
Antibiotic resistance —> demonstrates real life observation of evolution via natural selection
Molecular evidence —> Analysis of biological molecules such as DNA and proteins show similarities between species that indicate evolution of species from a common ancestor
Describe how genomics and proteomics can be used as evidence for evolution
Genomics —> looking at gene sequences; can find if a base sequence in equivelant genes in different species is similar, indicating a common ancestor
- level of similarity between base sequences of equivalent genes can give a measure of how long ago two species diverged from each other during speciation
Proteomics = study of proteins
- Involves sequencing proteins; this determines the order of amino acids in the primary structure of a protein
- similarity of amino acid sequence can be used to determine how long ago a species diverged
- enables scientists to establish the relationships between organisms
What is the role of the scientific community?
To assess evidence from scientific research in order to validate or reject scientific theories
How is research published into scientific journals ?
- Reading scientific journals
—> scientific research is written up + assessed by a panel of experts before being published in a scientific journal
—> panel of experts will peer review research, checking if results are valid and have been properly analysed
—> studies are continuously checked and can be withdrawn from a journal if found to be flawed
Describe the role of scientific conferences
—> meeting of a group of scientists in a particular field of study
—> scientists can present their findings for questions and discussion
—> conference members have the opportunity to speak with each other about their work and to share ideas and concerns
