Evolutionary Ecology in the Sea Flashcards
What is evolutionary ecology?
an interdisciplinary field that studies how the interaction of species with their biotic and abiotic environment is shaped by their evolutionary histories
Define speciation
the formation of one or more species from an ancestral species, as a result of reproductive isolation
What are the 4 types of speciation and what do they mean?
allopatric - geographic isolation
peripatric - small group breaks off from population
parapatric - colonisation on new niche
sympatric - no geographical or habitat barrier
What is MRCA?
Most Recent Common Ancestor
What is a clade?
a group of organisms comprising all the descendants of the MRCA
What are synapomorphies?
characters shared between the MRCA and all its descendants
What are labral spines?
sharp projections of the apertural lip found in some marine gastropods that are used to penetrate hard-shelled prey
Describe the distribution of Mexacanthina angelica and Mexacanthina lugubris
sister species geographically isolated by the rifting of the pacific plate from the north american (mainland) plate forming the gulf of California. angelica species found lining inner gulf and lugubris stay along outer coast
What is the pleistocene seaway?
a phylogeographic break believed to have geographically isolated mexacanthina lugubris and an intermediate species to mexacanthina angelica (around 500 kya) - did not cause speciation, but did cause phylogenetic variation
Define phylogeography
the study of historical processes influencing the modern distribution of a species (biogeography) using molecular tools - used to understand the process of genetic population divergence and speciation
What is a phlyogeographic break?
the location where two or more clades come into contact with one another
How does the morphology of C. fissus (prey) differ according to M. lugubris (predator) distribution?
Narrow and bent morphs are most common where M. lugubris is also most common
What might stop a selection pressure causing phenoplasicity from causing speciation?
long dispersal distances
What are marine terraces?
areas of distinct distribution as a result of glacial/interglacial cycles
Why is there generally a higher population diversity within a recently expanded geographic range compare to more central populations?
There is more time to accumulate genetic diversity and there is often higher gene flow between populations in the range centre
