Lesson 4 - Speciation Flashcards
meaning speciation
the formation of a new species
meaning hybridisation
the production of offspring as a result of sexual reproduction between individuals from 2 different species
meaning geographical isolation
when a physical barrier such as a river of mountain separates individuals from an original population
meaning ecological isolation
2 populations inhabit the same region, but develop preferences for different parts of the habitat
meaning seasonal isolation
when the timing of flowering or sexual receptiveness in some parts of a population drifts away from the norm of a group. This can eventually lead to the 2 groups reproducing at different times
meaning behavioural isolation
when changes occur in the courtship ritual or mating patterns so that some animals do not recognise others as being potential mates. This might be due to a mutation that changes the colour of patterns of markings
meaning mechanical isolation
when a mutation occurs that changes the genitalia of animals, making it physically impossible for them to mate successfully with members of the group
meaning allopatric speciation
speciation that takes place when populations are physically separated and there can be no interbreeding or gene flow between the populations
meaning endemic species
a species that evolves in geographical isolation and is found in only one place
meaning adaptive radiation
a process by which one species evolves rapidly to form a number of different species that all fill different ecological niches
meaning marspials
mammals that give birth to very immature young and then protect them in pouches
meaning monotremes
primitive mammals that lay eggs and feed their offspring with milk from mammary glands
meaning placental mammals
mammals that provide for the developing fetus during gestation through a placenta
meaning sympatric speciation
speciation that takes place between populations of a species living in the same place. They become reproductively isolated by mechanical, behavioural or seasonal mechanisms and gene flow continues between the populations to some extent as speciation takes place
