Speciation, Adaptive Radiation and Extinction Flashcards
how does allopatric speciation occur
an external barrier separates the population and so they diverge genetically
describe the founder effect
small populations become isolated llowing for rapid evolution due to non-random sample of genes
what is sympatric speciation
populations differ due to habitat, behaviour and adaptation, assortive mating may lead to genetic divergence
name the 3 possible causes of adaptive radiation
-key innovations
-environmental changes (new habitats)
-ecological changes (new opportunities)
give 3 key facts about bony fish
-single most species-rich vertebrate group
-third whole genome duplication
-buoyancy using swim bladder
what are pharyngeal jaws
a second set of teeth set within a fishs throat that can manipulate and help with swallowing prey
what occurred after the Cambrain Explosion
many weird and unsual creature appeared in the fossil records
what factors may have caused the Cambrian Explosion
-environmental changes (increase in oxygen)
-developmental changes (HOX genes)
-ecological changes (Evolution of eyes leading to predation)
what was the 6th mass extinction (the anthropocene)
the loss of the lost giants (megafauna)
name 3 animals lost due to the 6th mass extinction
-wooly mammoth
-megalania
-giant horned turtles
give 4 factors that caused the extinction of the megafauna
-human hunting of megaherbivores
-climate change
-disease
-secord-order predation
what process is thought to be capable of bringing the woolly mammoth back
DNA extraction from a mammoth preserved in permafrost that is grown in an artificial womb
what process can determine the relatedness of two members of a species
genetic tracking
give an example of an insular giant or dwarf that is still alive
komodo dragon
how do human jaws vary from that of a bony fish
mammalian skulls are mostly fused bone with the lower jaw moving whereas bony fish jaws have multiple moving parts
