Evidence for adaptation Flashcards
What does the speed of evolution depend on?
Genetic variation and strength of selection.
What is the harmonic mean?
The number of values being averaged divided by the sum of their reciprocals. They are usually better estimates of averages than means.
What is an adaptation?
An inherited aspect of an individual which allows it to outcompete other members of a population that lack the trait.
What is a selective sweep?
The idea that as adaptive mutations appear in a population will cause the nearby nucleotides to stabilise as well.
What are extended phenotypes?
The idea that for a gene to be adaptive it doesn’t have to affect its own phenotype - it can have an extended phenotype by creating a structure in another organism that enhances fitness. They are heritable and can be shaped by natural selection.
What is the idea of stabilizing selection?
That an intermediate feature may be favoured - such as gall size (consumed by woodpeckers).
What has been found with lactose tolerance?
It has only evolved where there are high levels of domesticated cattle. This is evidence of human evolution to their own food source.
How has the complex eye evolved?
They evolved in several lineages with each slight variant having a large advantage so would be selected for.
What are opsins?
A group of light sensitive proteins.
What are orthologs?
Genes related by common descent.
How has selection driven by humans affected crop diversity and yield, and size of hunted game?
It has been adaptive for crop diversity and maladaptive for the size of hunted game.
