Biology U3 T1 - Describing Biodiversity Flashcards
Biodiversity is…
the biological variety and variability of life on Earth. The three levels are genetic, species, and ecosystem.
Species richness is…
a measure of different types of species
Relative species abundance is…
the number of species in an area
Percentage cover measures…
small or dense organisms
Percentage frequency measures…
how often an organism appears across quadrats
Simpson’s Diversity Index is…
a measure of biodiversity
SDI=1-((∑n(n-1))/N(N-1) )
Species interactions include…
Predation +/-
Competition -/-
Mutualism +/+
Commensalism +/0
Amensalism 0/-
Parasitism +/-
Disease +/-
Neutralism 0/0
How do environmental factors limit species distribution and abundance?
Every organism has a slightly different tolerance limit
What is the morphological concept?
The Linnaean System - hierarchal, most inclusive to least inclusive, Did King Philip Come Over For Good Soup
What is the biological concept?
Methods of reproduction - a/sexual, r-strategists (unstable environments, short-lived, exponential, quick to mature), K-strategists (stable environments, long-lived, care for offspring, longer gestation periods)
What is the phylogenetic concept?
Molecular sequences - similar proteins, recent common ancestor, isolation = more mutations and different species, greater differences = longer divergence
A clade is…
a group of organisms that consists of a common ancestor and all its lineal descendants
What are the three assumptions of cladistics?
Common ancestry - all species share a common ancestor
Bifurcation - only one new species can arise at once
Physical change - change in appearance must occur to test DNA
Why is there a need for multiple definitions of species?
A singular definition doesn’t include the complexity of species and taxonomy of organisms
What is an example of an interspecific hybrid?
Liger, wholphin, mule
