APESUnit II: Evolution and Biodiversity

Genetics 101▪ Evolution: Change in genetic composition of a

population over time▪ population: all individuals of the same species

occupying the same area.▪ gene: unit of heritable information -usually associated

(at the molecular level) with a specific region located on the chromosome.

▪ allele: - one of two or more slightly different forms, or "variants" of a given gene.

▪ genotype: a selection of the genes that make up an individual.

▪ phenotype: the consequence(s) of all the allelic interactions that give rise to a visibly   determinable "type".

Genetics 101

▪ gene pool: all the genotypes within a population.▪ Mutation: mistake in copying of genetic code; if

mutation in sex cells it is inherited. ▪ Recombination: during cell division part of one

chromosome breaks off and attaches to another, which leads to new gene combinations and thus genetic diversity

▪ Evolution by Artificial Selection: Breeding dogs, horses, pea plants

▪ Unintended consequence of agricultural breeding is pesticide/herbicide resistance

▪ http://evolution.berkeley.edu/evolibrary/article/evo_14

I.Understanding Biodiversity

▪ HHMI: 2014 Lectures 2 and 3▪ Biodiversity: variety of earth’s species,

or varying life forms, the genes they contain, the ecosystems they live in and the ecosystem processes of energy flow and nutrient cycling that sustain life.

▪ Ecosystem Diversity▪ Species Diversity▪ Population Diversity▪ Genetic Diversity▪ http://media.hhmi.org/hl/14Lect2.html

2:00-6:30

II. Human Impacts on BiodiversityHuman Impact on BiodiversityUnderlying Causes: population growth, poverty, undervaluing natural capitalDirect Causes: HIPPCOH=Habitat Destruction, degradation and fragmentationI: Invasive SpeciesP=Population growth and increase resource useP=PollutionC: Climate ChangeO: Overexploitation

▪ Population▪ Land Transformation▪ Climate Change▪ Invasive Species▪ Diseases▪ The role of Protected

Areas▪ Synergistic Effects▪ http://

media.hhmi.org/hl/14Lect2.html 7:23-9:15

Invasive / Alien/Non-Native Species

▪ Native Species: live in their historic range-where they have lived for thousands-millions of years

▪ Alien: Live outside historic range▪ Trade, transport and agriculture are three of the

more common routes, or “pathways,” through which invasive species arrive.o Some species moved accidentally , some intentionally

▪ Asian Carphttp://www.cbsnews.com/video/watch/?id=5869154n

Ex. Zebra Mussels▪ feed by drawing water and filtering out most of the

suspended microscopic plants, animals and debris for food.

▪ can lead to increased water clarity and a depleted food supply for other aquatic organisms, including fish.

▪ The higher light penetration fosters growth of rooted aquatic plants which, although creating more habitat for small fish, may inhibit the larger, predatory fish from finding their food.

▪ Zebra mussel infestations may also promote the growth of blue-green algae, since they avoid consuming this type of algae but not others.

▪ Zebra mussels attach to the shells of native mussels in great masses, effectively smothering them

▪ http://www.nwf.org/What-We-Do/Protect-Wildlife/Invasive-Species/Ballast-Water.aspx

Kudzu

Population, Pollution and Climate Change▪ Pollution: DDT

▪ Population: Bald Eagle: saved eagle but shortage of fish mean they eat baby cormorant chicks

▪ Climate Change: Cannot adapt fast enough; Polar Bear

Overexploitation: Hunting, Fishing, Illegally killing, capturing and selling wild species

III. Measuring Biodiversity

▪ Diversity and Abundance▪ Species Richness:

Number of different species▪ Species Evenness:

abundance / proportion of individuals within the species. Are all species represented by similar numbers of individuals?

▪ Species Richness Influenced by many factors▪ Latitude: richness declines as we move

from equator toward North or South Pole.▪ Time: Longer a habitat exists, the more

colonization and speciation▪ Theory of Island Biogeography:

Influence of SIZE of habitat an d DISTANCE

▪ Conservation: Should we establish several small reserves or a single large reserve?