Chapter 54 Flashcards
Where and what led to the loss of habitat for the orangutans
-Borneo
-rainforest cut for wood and to make room for oil palm plantations
Def: Genetic Diversity
the total genetic information contained within all individuals of a population, species or group of species
How is genetic diversity measured
as the number and relative frequency of all genes (and their alleles) present in a species
What two technical breakthroughs have advanced our ability to catalog genetic diveristy
- The ability to sequence the entire genome of multiple individuals of a species
- Environmental sequencing: when researchers sample soil or water and sequence genes or alleles present
Why is genetic diversity important
it represents the adaptive capacity (ability to persist despite changes in the environment) of a group
What factor must be high at any species richness of diversity to be high
evenness
What does DNA barcoding do
uses well-characterized gene sequence to identify distinct species
-allows non-specialists to identify species
-researchers to identify specimens even from leftover tissue
Taxonomic diversity
species that are part of lineages with many species
Ecosystem function
the sum of the biological and chemical processes
How many species are estimated to be living today
5-100 million
How many species have been cataloged
1.5 million
Endemic species
species that are found in a particular area and nowhere else
What are some general trends in species richness and endemism
-species richness is highest in the tropics and declines towards the poles
-biodiversity is higher on land than in the sea
-areas will greater geographical variation are more diverse
What percentage of all species are contained in the tropical rain forests compared to the area of earths land they cover
50% of species
7% of earths land
What are the 6 main causes of species endangerment
-Habitat loss
-invasive species
-over-exploitation
-pollution
-native species interactions
-natural causes
