Macroevolution 3 Flashcards
(13 cards)
What is symbiosis ?
A relationship between two different species where at least one species benefits
There are 3 types: mutualism, commensalism and parasitism.
What is mutualism ?
Where both species benefit
What is commensalism ?
One species benefits while the other species is not affected
What is parasitism ?
One species benefits while the other species is harmed
What is an example of mutualism ?
Algae live in sloths fur which provide camouflage and nutrients to the sloth.
The algae benefit by having a most, shaded habitat rich in nitrogen in the fur.
Moths live in the fur, lay eggs in sloth poo. Their waste helps feritilize the algae, boosting its growth.
What is obligate mutualism ?
Where you can’t replace one of the organisms. If one didn’t exist, the other wouldn’t either.
Eg. Pollinator- plant relationship (yuccas and moth, figs and wasps)
What is co-evolution ?
Occurs when two species evolve in response to each other, often because they are closely linked by mutualism or parasitism
Angiosperms
Flowering plants
What is co-speciation ?
Where two or more species speciate in response to each other, creating parallel evolutionary trees
What is incongruence ?
When phylogenetic tree do not align, meaning different genes suggest different relationships between the organisms
What are homeotic genes ?
They are master regulatory genes that control the developmental fate of groups of cells during early embryonic development and in terms of their position along the body axis.
Main type are Hox genes
What do Hox genes do ?
They determine the identity of body segments.
They activate “builder” genes in a region for contrast the structure, such as wings, legs etc.
Mutations can occur in fruit flies that cause legs to be grown instead of antennae or extra wings.
What homeotic genes have retained their original function ?
- Gene controlling eye development
- Gene controlling heart development
