environmental biology applied to a local (relative) scale (Northern California)
“structural levels of life”
compartmentalization of life with regard to the biosphere concept
biology — the study of life and living organisms, genetic adaptations and growth, taxonomy, evolution, identification
several unifying concepts to biological disciplines: structural levels and emergent properties of life
structural reflects the complexity
emergent defines what a living being is
some components do not consist of living things (molecules), but many do
molecule — non-living
cell — cumulation of molecules with a living, functioning concept
tissue
organ — functional structure
organism — living entity
population — a collective of the same kind of organism, dependent on where it is also specified
community — groups of populations within a specific area
ecosystem — the community of organisms and the environment and resources which they use; both living and non-living components included
biosphere — every place on the planet which living things exist; non-living only, and specific to places and areas (environments)
emergent properties of life
combined characteristics which define life
all living things have all of the below components
order, organization, and hierarchy
the ability of reproduction for both cells and offspring
the ability to grow and develop
the need to use energy
the ability to maintain your body/metabolize
the ability to respond to the environment/environmental stimuli
the ability to adapt to the environment and genetics
the ability to evolve
scientific method
ask a question/make an observation
propose a testable hypothesis
develop a deduction (written as an if… clause)
testing/experimentation/exposure
conclude if the hypothesis has been supported or invalidated based on the tests
scientific theories are accepted explanations for a phenomenon that are based on large amounts of evidence obtained from testing vs. conjecture
scientific method is practiced through an individual group; scientific process is practiced via the larger scientific community
publishing, peer review, scientific journals; passes through rapid, larger-scale acceptance/rejection
natural selection and speciation
living things use energy for metabolism, growth/development, and reproduction in that order
by using less energy on metabolism, more energy can go into development and reproduction
Evolution: the change in a population’s genetic makeup (gene pool) through successive generations. Populations evolve.
Microevolution: the small genetic changes that occur in a population.
Macroevolution: long-term, large-scale evolutionary changes that occur in groups of species where new species are formed from ancestral species.
selective pressures
environmental resistance factors
environmental pressures
natural selection pressures: primary force is competition for resources within populations
environmental resistance: physical and biological factors’ effect in preventing species from reproducing at maximum rate
natural selection affects the gene pool
adaptation occurs at an individual level
shifting gene pools → biological evolution
different forms
differential reproduction
stabilizing selection
intersexual selection
adaptive radiation
selective breeding
phenotypic plasticity
alfred russell wallace: distinct differences found on the malay archipelago: animals on the western line had asian ancestry, eastern had australian ancestry
“wallace line”
major tenets/assumptions of natural selection:
all species have immense reproductive potential unless checked/limited
natural resources are limited which checks/limits species reproduction
genetic variation exists in the population
overpopulation/above capacity limits the number of surviving offspring in each generation
some individuals with a specific phenotype have a greater fitness in the population than others
favorable characteristics/phenotypes are more likely to prevail in the population in each generation