APES Unit 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 ▪

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 ▪ 2:00-6:30

II. Human Impacts on Biodiversity Human Impact on Biodiversity Underlying Causes: population growth, poverty, undervaluing natural capital Direct Causes: HIPPCO H=Habitat Destruction, degradation and fragmentation I: Invasive Species P=Population growth and increase resource use P=Pollution C: Climate Change O: Overexploitation ▪ Population ▪ Land Transformation ▪ Climate Change ▪ Invasive Species ▪ Diseases ▪ The role of Protected Areas ▪ Synergistic Effects ▪ l/14Lect2.html 7:23-9:15 l/14Lect2.html

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 Carp

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

▪ Species/Ballast-Water.aspx Species/Ballast-Water.aspx

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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?