1. Biodiversity

2. Biodiversity
The variety of Earth’s species, the genes they contain, the ecosystems in which they live, & their functions in energy flow & nutrient cycling
Destroying the rain forest for economic gain is like burning a Renaissance painting to cook a meal.
~ E. O. Wilson

3. Three Components

4. What affects biodiversity?
Natural Selection/Evolution
Speciation
Extinction

5. Evolution
Change in a species’ genetic makeup over time

6. Natural Selection
Individuals with certain traits are more likely to survive and reproduce under a particular set of environmental conditions than those without the traits
Begins with mutations

8. Start Video: 32:27 End Video: 41:528

9. Adaptation Video

10. Resistance
A group of bacteria, including genetically resistant ones, are
exposed to an antibiotic
Normal bacterium
Resistant bacterium
Eventually the resistant strain
replaces the strain affected by
the antibiotic
The genetically resistant bacteria
start multiplying
Most of the normal bacteria die

11. Limits to Natural Selection
When a change in environmental conditions occurs, a gene/mutation must already occur in the population
Reproductive capacity
Fast reproduction = quicker adaptation
Slow reproduction = slow adaptation

12. r Selected Unstable environments Small body size High fecundity
Early maturity
Short generation time
Less parental care

13. K selected Stable environments Large body size Long life expectancy
Later maturation
Few offspring
More parental care

15. Reproductive Strategies
R- strategists
K-strategists
Mature rapidly
Mature slowly
Short lived
Long lived
Tend to be prey
Tend to be both predator and prey
Have many offspring and overproduce
Have few offspring
Low parental care
High parental care
Generally not endangered
Most endangered species are K-strategists
Wide fluctuation in population density (booms and busts)
Population stabilizes near carrying capacity
Population size limited by density-independent factors (climate, weather, natural disasters, requirements for growth)
Density-dependent limiting factors to population growth stem from intraspecific competition and include predation, parasitism, and migration
Tend to be small
Then to be larger
Type III survivorship curve
Type I or II survivorship curve
Examples: most insects, annual plants, bacteria, rodents
Examples: humans, elephants, cacti and sharks

16. Survivorship curves
What do these graphs tell about survival & strategy of a species?
Generalized life strategies 25
1000
100
Human
(type I)
Hydra
(type II)
Oyster
(type III) 10 1 50
Percent of maximum life span 75
Survival per thousand
I. High death rate in post-reproductive years
II. Constant mortality rate throughout life span
A Type I curve is flat at the start, reflecting low death rates during early and middle life, then drops steeply as death rates increase among older age groups. Humans and many other large mammals that produce few offspring but provide them with good care often exhibit this kind of curve. In contrast, a Type III curve drops sharply at the start, reflecting very high death rates for the young, but then flattens out as death rates decline for those few individuals that have survived to a certain critical age. This type of curve is usually associated with organisms that produce very large numbers of offspring but provide little or no care, such as long–lived plants, many fishes, and marine invertebrates. An oyster, for example, may release millions of eggs, but most offspring die as larvae from predation or other causes. Those few that survive long enough to attach to a suitable substrate and begin growing a hard shell will probably survive for a relatively long time. Type II curves are intermediate, with a constant death rate over the organism’s life span. This kind of survivorship occurs in Belding’s ground squirrels and some other rodents, various invertebrates, some lizards, and some annual plants.
III. Very high early mortality but the few survivors then live long (stay reproductive)

17. Survivorship Curves Type Descriptions I Late Loss
Reproduction occurs fairly early in life. Most deaths occur at the limit of biological life span. Low mortality art birth. High probability of surviving to advanced age. Advances in prenatal care, nutrition, disease prevention and cures mean longer life spans for humans. Examples: humans, annual plants, sheep and elephants.
II Constant Loss
Individuals in all age categories have fairly uniform death rates. Predations affecting all age categories is primary means of death. Typical of organisms that reach adult stages quickly. Examples: rodents, perennial plants and songbirds.
III Early Loss
Typical of species that have great numbers of offspring and reproduce for most of their lifetime. Death is prevalent for younger members of the species (environmental loss and predation) and declines with age. Examples: sea turtles, trees, internal parasites, fish and oysters.

19. Speciation
One species splits into two of more different species Two mechanisms: 1. Geographic Isolation 2. Reproductive Isolation

20. Geographic Isolation
Occurs when a population become physically isolated from one another for a long period of time
mountains rivers landslides

21. Reproductive Isolation
Differences in isolated groups become so great, they can no longer interbreed
Behavioral changes
Physical changes
Genetic changes

22. Speciation in Action
California Salamanders

23. Extinction Two Types 1. Biological
The process in which an entire species ceases to exist
Local
A population of a species becomes extinct over a large region but not globally

24. Passenger Pigeon 3-5 billion – first European settlers Last died 1914
Cincinnati zoo - Martha
Caused by
Habitat destruction
Over hunting

25. Endemic Species Highly vulnerable to extinction
Species only found in one area
Highly vulnerable to extinction

26. Types of Biological Extinction
Background extinction
Species disappearing at a slow rate
Mass extinction
Significantly high rate of extinction
25-95% of global species gone
Largest Permian – 96% of species died
Promotes evolution
The Permian mass extinction has been nicknamed The Great Dying, since a staggering 96% of species died out. All life on Earth today is descended from the 4% of species that survived. The event turns out to have been complex, as there were at least two separate phases of extinction spread over millions of years. Marine creatures were particularly badly affected and insects suffered the only mass extinction of their history. Many causes have been proposed for the event: asteroid impact, flood basalt eruptions, catastrophic methane release, a drop in oxygen levels, sea level fluctuations or some combination of these.

27. Endangered Species Reasons Habitat loss/fragmentation Invasive species
So few individuals that the species could become extinct
Reasons
Habitat loss/fragmentation
Invasive species
Pollution
Population growth
Climate change
Overconsumption

28. Keystone Species
A species that plays a critical role in ecosystem structure & whose impact on the community is greater than expected based on abundance
Removal greatly affects
the food web

29. Keystone Species
Sea Otters

30. Keystone Species
Grey Wolves

31. Invasive Species
A non native (introduced) species that adversely affects a habitat they invade ecologically and/or economically

32. Invasive Species Where do they come from? Horticulture Conservation
Accidental

33. Invasive Species Characteristics
Tolerate a variety of habitat conditions
Reproduce rapidly
Short generation time
Great competitors
generalist
Lack of predators
Genetic variability

34. Indicator Species
Species that provide early warning signs of damage to an ecosystem
Examples:
Lichens (air quality)
Stoneflies (aquatic – DO)
Pika – (climate change)

35. Levels of Diversity Ecosystem Diversity Species Diversity
Different habitats, niches, interactions
Species Diversity
Different types of organisms
Genetic Diversity
Different genes & combinations within a population

36. Measuring Species Diversity
Two components:
Species richness
Number of unique species
Species evenness
Number of individuals of each species in an area

37. Monoculture Opposite of biodiversity
Growing only one species of organism
Problem?
disease

38. Which do you think is more diverse?A B

39. Which do you think is more diverse?A B

40. Which do you think is more diverse?A B

41. Leaf Litter Decomposition Recycling nutrients
Insects are critical to the health of the environment.
Decomposition
Recycling nutrients
Lower invertebrates result in less
stability and health
With less insects within the leaf litter can lead to delays in the decomposition process.
Delays in the process can result in decomposition to take decades as opposed to a few days. 41

42. Laboratory Set Up Leaf litter from bags into funnels
Funnel was placed over beaker with
~100 mL ethanol
Removed preserved insects next day
Microscope for observation
Classified and tallied number of insects 42