Exam 3 Review Flashcards
Biodiversity
The variety of living things on earth
3 measures of biodiversity
A) Genetic diversity: variety of genetic differences within a species, ex. Eye colors
B) Species diversity: number of different kinds of organisms in an ecosystem
C) Ecological diversity: complexity of a biological community ex. Number of niches, trophic levels, different soil types
Why do certain areas have a higher species diversity?
How many known species are there?
They have high ecological diversity
1.8 million
Why should we protect species? (Why save biodiversity)
A) Human centered-how do we benefit?
B) Other organisms deserve to survive
7 reasons to save biodiversity
1) ecological 2) evolutionary (genetic diversity is required for natural selection 3) utilitarian (all food and ⅓ medicines come from nature 4) economic 5) aesthetic 6) ethical/spiritual/religious/ 7) physiological
What is meant by the phrase….. “we live on an unexplored planet”?
Earth is 80% undiscovered
There are 5-100 million undiscovered species, thousands are discovered every year
What are most of the species that we know of?
Insects
Order for classification (binomials)
Kingdom, Phylum, Class, Order, Family, Genus, Species
What is a species defined as?
All organisms genetically similar enough to A) breed, B) produce live offspring, C) produce fertile offspring, and D) reproduction must happen in nature
Pre-zygotic and post-zygotic barriers that surround species
A) Reproductive Isolation: mechanisms, behaviors, and physiological processes that prevent two different species from reproducing, ensuring that any offspring would not be fertile
ex. Different mating times, mating behavior, mechanical Difficulties
B) Geographic separation
Biodiversity hotspots
High in endemic species
(species that only exist in specific geographic areas, like pandas in bamboo forests)
Indonesia and biodiversity
1.3% of the Earth’s land, 1/3 of Earth’s insects, 45% of fish and shelled animals
High ecological diversity-tropical rainforests and coral reefs
Why do so many species live in Tropical Rainforests?
A) stable climate= high primary productivity
B) Large area
C) Lack of natural catastrophe like forest fires
D) Intermediate disturbances like small fires= new species growth
E) Complex forest structure= lots of ecological niches
Rivet or brick model
Losing one species may not be a big deal, but losing multiple species is like losing a lot of Jenga pieces or bricks from a wall, the whole ecosystem collapses
Natural vs anthropogenic extinction
Natural extinction=natural rate of extinction (3-30 species/year)
When species go extinct naturally, they have time to slowly adapt and pass their genes on to new species ex. Dinosaurs and birds
Anthropogenic extinction=human caused extinction (happens too quickly, no adaptations can occur)
