BIOL 1205 Final

Define biodiversity at the four levels:

• Molecular (genetic).

• Species.

• Population.

• Ecosystem.

Define ecosystem services:

Soil stabilization, water resources, etc. Benefits we receive from the ecosystem in turn for maintaining it.

Benefits of biodiversity:

Cultural, societal, medicine, food, recreation.

Characteristics of life:

1. Composed of Cells

2. Living things Grow

3. Use energy for growth and maintenance

4. Maintain Homeostasis

5. Living things Reproduce

6. Adapt to their environment through successive generations (evolve)

7. Respond to their environment

How spontaneous generation was disproved:

Redi (1668) disproved Spontaneous Generation through an experiment in which he placed meat in a series of jars.

Abiogenesis (Chemical Evolution)

Chemicals and vapours, gave rise to compounds like DNA, eventually leading to life on Earth.

Stages of Chemical Evolution

1. Abiotic synthesis of small organic molecules 

2. Joining of molecules into polymers

3. Origin of boundary

4. Life-like properties, such as heredity

Panspermia

Life exists throughout the universe, and is spread by asteroids.

Hydrothermal Vents (Theory)

Essentially, hydrothermal vents provided the necessary chemicals and nutrients for life to exist around them, then spreading to other areas of the Earth.

Three misconceptions in Evolution:

1. Evolution does not equal improvement.

2. Complex does not equal more evolved.

3. Organisms do not evolve on purpose.

Biological Evolution (Define)

A change in the allele frequency in a population over time that results in a population-level phenotypic change.

Macroevolution (Define)

Large-scale genetic changes, resulting in a new species.

Mutation (Define)

ANY change in the original DNA code.

Alleles (Define)

DIFFERENT versions of the SAME gene.

Genotype (Define)

An individuals combination of alleles.

Diploid vs Haploid

• Diploid: 2 copies of each gene.

• Haploid: One copy of each gene. (bacteria).

Complete Dominance (Define)

One allele is expressed in the phenotype and the other is hidden.

Co-dominance (Define)

Both phenotypes are expressed.

Incomplete Dominance (Define)

The phenotype is mixed.

Allele Frequency (Define)

Percentage or proportion each allele is represented in the population.

Microevolution (Define)

Allele frequency changes over time, but the organisms are still considered to belong to the same speices.

Causes for genetic changes:

• Mutations.

• Natural Selection.

• Genetic Drift.

• Gene Flow.

Three things necessary for natural selection:

1. Ther must be diversity within the individuals of the population.

2. There is a competition for existence.

3. HEredity.

Genetic Drift (Define)

Allele frequency is changed due to chance alone. Phenotype has NO influence on the outcome.

Gene Flow (Define)

AKA migration. Any movement of individuals, and/or the genetic material they carry, from one population to another.

Speciation (Define)

The formation of a new speices. A lineage-splitting event in phylogenetics.

Morphological Species Concept (Define)

Defining species off of shared phenotypic (physical) traits.

Sexual Dimorphism (define)

Phenotypic differences in a species between individuals of opposing sexes.

Convergent Evolution (define)

Different species evolve similar traits and phenotypes despite bein unrelated.

Biological Species Concept (Define)

Defining a species by which animals can breed to produce viable offspring.

Phylogenetic Species Concept

Defines a species through the smallest cluster of members on a line of descent.

Allopatric Speciation (define)

Formation of a new species through the splitting of a population often by a geological barrier.

Parapatric Speciation (Define)

Adjacent populations evolve into distinct species while maintaining minimal contact zones between the two populations.

Sympatric Speciation (define)

Population splits without a physical barrier.

Parthenogenesis (Define)

A form of asexual reproduction in which an embryo develops directly from an unfertilized egg cell without the need for sperm. Think Kurourushi from JJK.

Sexual Selection (define)

A special case of natural selection. Phenotypes are selected for beacuase they provide a mating advantage, not necessariy a survival one.

Taxonomy (Define)

System of classifying organisms. Linnaeus did this based on similarities between organisms on the phenotypic scale.

Taxon (Define)

A single level in Linnaeus’ taxonomic classification system.

Phylogeny (Define)

Evolutionary history.

Phylogenetic Systematics (Define)

Science of classifying organisms based on their evolutionary history.

Two types of prokaryotes (Single-celled):

• Bacteria: found everywhere.

• Archaea: extremophiles.

Protists (Summary)

• Eukaryotic, single celled, some multicellular.

• Freshwater, marine, parastic.

• Huge number of individuals.

Animas are:

• Eukaryotic

• Multicellular.

• Hetertrophic organisms that obtain nutrients through ingestion.

• Able to digest food within their bodies.

• Mobile at some point in their lives.

• Lack cell walls.

Cambrain Explosion (Define)

• As many as 150 million animal phyla appear suddenly in the fossil record around 540 million years ago.

Burgess Shale (Define)

A fossil deposit, key to explaining the cambrian explosion.