Slide Set 2 Flashcards
What are wallaces 17 Principles?
- Distance by istelf does not determine the degree of biogeographic affinity
- climate has a strong effect on taxonomic similarity but the relationship necessarily linear
- things you need to know in order to determine biological patterns
- fossil record is important but incomplete, it provides evidence for past migrations of organisms
- recent climate an geological events have a large effect on current composition for past migrations of organsims
- factors of importance to determine the distribution, dispersal and extinction of biota include; competition, predation, and other biotic interactions
- discontinuities in range can be due to extinctions of intermediate populaions or to patchiness of habitats
- speciation can occur through geographic isolation followed by local adaptation
- disjunctions of genera are older than disjunctions of single species; the higher the taxonomic category, the more ancient the disjunctions
- long distance dispersal is possible and probable
- distributions of organisms with poor powers of dispersal indicate past land connections
- in absence of competitors or predators, organisms on isolated land masses can diversify
- when two large landmasses are reunited after long separation, extinction can occur as species encounter new competitors
- procsses acting now may not be at the same intensity as those processes in the past
- to analyze the biota of a region one must study the distributions of its organisms and relatives beyond that region
- islands fall into 3 categories
- islands are important test cases to study and understand distributions and speciation events, and adaptations
according to wallace what are the things you need to know in order to determine biological patterns?
- knowledge of distribution
- a true and natural system of classification
- acceptance of evolution by natural selection
- knowledge of extinct forms
- knowledge of ocean floor, geological stratigraphy and past connections between land masses
islands fall into what 3 categories?
- continental- recent separation
- continental- ancient separation
- distant oceanic- volcanic or coral
Why do we study invasive species?
- the pace of invasion is very rapid, giving us opportunity to study the relative importance of ecological processes such as competition, predation, parasitism and disease
- mechanism of establishment , facilitation and tolerance can be studied
- aftermath can be studied
what was the case of the prickly pear cactus?
introduced into australia, used for scale insect for red dye for uniforms, no natural enemies so spread on wide scale and could not be controlled. predator cactoblast was able to control species
what was the case of the invasion of the great lakes?
zebra mussels and quagga mussels spread to the great lakes through fishing boats bails and gear. they came from the black and caspian sea, no predators so they spread rapidly.
what was the cause of the lake erie algal blooms?
phosphors input from farming practices, also the invading mussels dont consume the cyanobacteria
what are the five contrasting patterns of distribution?
- endemic patterns
- circumboreal patterns
- overlapping (ring species)
- expanding (range extension)
- Relict (range reduction)
what is the restricted and endemic distribution?
part of the hawaiian island chain, volcanic origin, multiple cases of endemic species
what are the picture wing flies of hawaii?
112 distinct species on this island, differ in morphology, pigmentation and behaviour, little change in dna. they were isolated over a long period of time, adaptive radiation, many endemic species
what does eurytopic mean?
wide range of ecological tolerances
what is an example of world scale distribution?
common blue damselfy , northern hemisphere
what are some ecological reasons for world scale distribution to occur?
species can use many habitats, has a wide tolerance for food, climate, physical conditions, good competitor
what is an example of a ring species or overlapping distributions?
two species L fuscus and L argentstus (seagulls) both occur in northern europe, they are true biospecies and have evolved from one ancestor, theyre separate clines are said to reveal the pathway of evolutionary development of two species
the ring species story is based on a hypothesis first put forward by ______
Mayr (1942)
what is the general idea of the ring species story?
Mayr postulated a single origin in the caspain sea that gave rise to three lineages; 1. west (mediterranean species of gulls) 2. east (inner asian gulls) 3. north (arctic ocean gulls)
In turn the arctic species then gave rise to three new species westward and eastward, the two meet in northern europe
what are the limits to the spread of the zebra and quagga mussels in north america?
temperature, and water chemistry including (calcium, magnesium and pH)
Range expansion distribution is linked to _________ activities
human
what is an example of relict species?
the tulip tree, was once widespread but has become limited to two remaining species
spacial, _______ and taxonomic scales influence distribution patterns
temporal
define circumboreal
floristic region within the Holarctic Kingdom in Eurasia and North America
define eurytopic
tolerate a wide range of habitats or ecological conditions
define stenotopic
tolerate only a restricted range of habitats or ecological conditions
define polytopic species
occurring or originating in two or more areas
define cline
gradient of morphological or physiological change in a group of related organisms usually along a line of environmental or geographic transition
define taxonomy
branch of science concerned with classification, especially of organisms; systematics
define cosmopolitan
range extends across all or most of the world in appropriate habitats. Such a taxon is said to exhibit cosmopolitanism or cosmopolitism. The opposite extreme is endemism
define refugium
an area in which a population of organisms can survive through a period of unfavorable conditions, especially glaciation.
define evolutionary divergence adaptive radiation
process in which organisms diversify rapidly from an ancestral species into a multitude of new forms, particularly when a change in the environment makes new resources available, creates new challenges, or opens new environmental niches
define allopatry?
populations of related organisms are unable to interbreed because of geographic separation. The development of new species as a result of the geographic separation of populations is called allopatric speciation
define taxon
taxonomic group of any rank, such as a species, family, or class.
define endemic species
are plants and animals that exist only in one geographic region
define relict species
plant or animal is a taxon that persists as a remnant of what was once a diverse and widespread population.
define vicariance
separation or division of a group of organisms by a geographic barrier, such as a mountain or a body of water, resulting in differentiation of the original group into new varieties or species.
