Topic 3.2 - Creation of diversity Flashcards
Describe evolution
The change in gene pool, that allows for variation, over time
Describe adaptation
A change in phenotype (physical characteristic) for the purpose of surviving a condition in a habitat
Describe natural selection
A mechanic of evolution whereby organisms whose physical characteristics are adapted to a specific niche and are able to outlive other organisms and reproduce to produce fertile offspring.
What did Charles Darwin propose about evolution
Evolution is about ‘Survival of the fittest’ and that variation occurs from evolution. More specifically, the intertwining of genotypes through meiosis produces genetically variable organisms that have different physical characteristics which may be an adaptation for a specific niche.
Describe speciation
The creation of new species through biological processes.
What encourages change in part of an organisms population
Isolation, the three types include:
- Geographic isolation (the region in which they inhabit becomes isolated)
- Temporal isolation (some species have different times which they operate on; thus, they don’t mix)
- Behavioural isolation (some species have different mating rituals)
What allowed Darwin to make his claims on evolution?
His research on finch beaks in the Galapagos islands, which were adapted to a specific purpose. i.e. stout beaks for seeds and longer beaks for predating on insects
How does environmental change drive evolution?
An example of how environmental change drives evolution is the fact that some insects canbecome resistant pesticides overtime. As r-strategist species reproduce rapidly, many different variations in a species’ gene pool will be created allowing for mutations in genes due to the processes in meiosis. A named example is the Colorado potato beetle.
Explain how the separation of two species can lead to speciation.
Geographical separation of two different species of animal will not allow their gene pools to intermingle and combine during the processes of sexual reproduction, this in turn reduces the potential species diversity in these two separate areas as the species present in both areas has decreased, therefore lowering the gene pool which creates a distinct species type for each area it is adapted for.
What is the evidence for evolution?
Remains of dead organisms that have been fossilised in rock, or that still exist in the ground as bones, allow scientists to analyse and determine the differences between organisms now and then. There is plenty of evidence that supports the theory of evolution, for example homo habillus and homosapien.
How do plate tectonics affect the amount of species?
The movement of plate tectonics shifts the earth’s crust which causes geographic isolation, which leads to speciation. Geological disasters that arise from the shifting of earth’s plates, like volcanic eruptions or earthquakes and tsunamis, can drastically affect the population of a species, which (if endemic) could render the species extinct as it no longer exists. Plate tectonics can also create valleys and mountains, which can cause geographical barriers to exist, furthering speciation.
