Species And Adaptations Flashcards
Define mutations
Change in the sequence of an organisms DNA
Define gene flow
Movement of genes from one population to another
Define sexual reproduction in terms of genes
New gene combinations via random mating and meiotic division
Define gene drift
Change in allele frequency due to random event or sampling of individuals
What is the founder effect
Few individuals start a new population with a different allele frequency that the original
Define species
Individuals with the potential to interbreed and produce fertile offspring in nature
What are 3 problems with that definition of species
- Difficult to apply to fossils
- Asexual organisms don’t fit the criteria
- Horizontal gene transfer
What is allopatric speciation
- geographic isolation
- species separated by time or space
What is sympatric speciation
- species occupy the same place at the same time but speciation still occurs
E.g. flys feed and mate on apples. But some only eat green or red. So flys that’s like red apples will only mate with other flys on red apples not green. So the population will begin to diverge.
What is sympatric speciation by polyploidy
A process where a chance doubling of chromosomes in a species leads to reproductive isolation
Common in plants
What is ring species speciation
- Population of a single species
encircle an area of unsuitable
habitat - At the end, the populations have expanded so far that the circle ends cannot reproduce
- Creating reproductive isolation
Why can’t cows evolve to fly
- Because they aren’t built for that adaptation.
- They can’t devolve to be better fitted to fly (smaller, less dense bones).
- It’s a limitation in the anatomy stopping it
Define morphology and physiology
- Morphology – the physical structure of an animal
- Physiology – the function of that morphology
Define adaptation
A feature produced by natural selection for its current function
Define exaptation
A feature that performs a function but that was not produced by natural selection for its current use
