BIO 181- Ecology, Evolution, and Biodiversity

Descriptive Based Science

Data gathering to inform a hypothesis

Hypothesis Driven Science

Conducting an experiment to test a proposed explanation

Hypothesis

Proposed explanation for a natural phenomenon or observation

Theory

An explanation of a natural phenomenon that has been supported by many experiments over a long period of time ex. thermodynamics, evolution

Inductive Reasoning

Studying specific items to derive generalizations

Deductive Reasoning

Studying generalizations to derive specific items

Variable

An aspect of an experiment being studied

Independent Variable

The aspect of an experiment chosen or manipulated by the scientists

Dependent Variable

The aspect of an experiment that is measured for change

Controlled Variable

Aspect of an experiment kept constant across all groups

Treatment Group

The individuals in an experiment receiving treatment

Control Group

Baseline measurement, the individuals in an experiment not receiving treatment

Qualitative Data

Data organized into categories where no one category has a higher value than another

Quantitative Data

Data organized by values and units of measure

Ordinal Data

Distance between values with no specific meaning ex. # of species

Interval Data

Specific numerical distance between variables ex. Time, temperature

Table

Best visual representation of specific values for a small number of data points

Graph

Best visual representation of trends across many data points

Title

Part of a scientific article that state what the article is about

Abstract

Part of a scientific paper that is written after the experiment and summarizes the whole article

Introduction

Part of a scientific paper that establishes the area in which the research takes place, the research problem, the importance of the research, and the guiding question or hypothesis.

Materials and Methods

Part of a scientific paper that describes the research procedure

Results

Part of a scientific paper that reports the outcomes of the research procedure

Discussion

The part of a scientific experiment that interprets the results, explaining them and comparing them to the results of other experiments

Conclusion

Part of a scientific paper that focuses the reader on what is important about the research, its contribution to the larger area of study

References

Part of a scientific paper that lists the sources used in the article.

Biodiversity

The variety of life in the world or in a particular habitat or ecosystem

Beetles

The most common animal on Earth

Characteristics of Life

Cells and organization, energy use and metabolism, response to environment, regulation and homeostasis

Levels of Organization

Atoms, molecules/macromolecules, organelles, cells, tissues, organs, organisms, populations, communities, ecosystems, biosphere

‘Father of Taxonomy’

Linnaeus

Binomial Nomenclature

The two-part system for naming and classifying species

Structure of a Scientific Name

Genus species

Species

Generally, a group of similar organisms that can interbreed with each other and cannot interbreed with other groups of organisms

Subspecies

Can interbreed with others in the species but isolation has caused them to develop distinct traits

Prokaryote

Cells that lack membrane bound organelles, specifically a nucleus

Eukaryote

Cells structured into membrane bound organelles

Domains of Life

Bacteria, archaea, eukarya

Mathias Schleiden

Founder of the theory all life is made up of cells

Robert Hooke

Creator of the first microscope in 1665

Anton van Leeuwenhoek

Refiner of the microscope with up to 300X magnification

Charles Darwin

Man attributed with the theory of evolution

Finches

Animal that Darwin observed to develop his theory of evolution

Selective Pressure

An environmental factor that drives the survival and reproductive success of a species

Origin of Species

Book published by Charles Darwin in 1859 on his theory of evolution

Galapagos Islands

Where Charles Darwin primarily developed his theory of evolution

Descent with Modification

Organisms are related through descent from a common anscestor

Natural Selection

A population changing over time if individuals that possess certain traits leave more offspring than others

Evolutionary Adaptation

An accumulation of inherited traits that increase an organisms’ survival and reproduction in specific environment

Evolution

Change over time in the genetic composition of a population

Microevolution

Change in a single trait frequency within the same species

Macroevolution

Large changes in a species over a long period of time, develops a new species

Gene

Organized sequence of DNA that form a hereditary unit

Allele

Different forms of a particular gene

Dominant Allele

Allele that generally always presents when in the gene

Recessive Allele

Allele that generally only presents when it is the only allele in the gene

Genotype

The genetic composition of an organism

Heterozygous

Two different alleles paired together

Homozygous

Two of the same alleles paired together

Phenotype

The expression of an organisms genes

Gene Pool

All the genes present in a population

Darwinian Fitness

The relative likelihood based on the environment that a genotype will contribute to the gene pool of the next generation as compared with other genotypes

Mean Fitness of a Population

The average reproductive success of members in a population,

Evolutionary Mechanisms

Mutation, selection, random genetic drift, gene flow, non-random mating

Mutation

Random genetic changes that can introduce a new allele into the gene pool, rare

Selection

Natural or sexual, forces act on existing genes changing their frequency

Genetic Drift

Changes in the genes present in population’s gene pool (bottleneck and founder’s effect)

Gene Flow (Migration)

Changes to a population’s gene pool as individuals come in and out

Non-random Mating

Reproductive between individuals following patterns rather than being completely random

Heritable Varation

Survival depends partly on inherited traits, influencing individual fitness and reproductive success

Directional Natural Selection

Favors an extreme phenotype, changes the average value of a trait without necessarily changing the variation

Stabilizing Natural Selection

Favors the average of a trait, reduces variation

Disruptive Natural Selection

Both extreme phenotypes favored, increase in variation and a bimodal curve

Balancing Natural Selection

2+ alleles kept at the same level of presence in a population

Heterozygous Advantage

When a heterozygous allele is favored in a population, ex. Malaria and sickle cell anemia

Oscillating Natural Selection

The favored genotype changes as the environment changes in predictable ways

Sexual Selection

“The advantage that certain individuals have over others of the same sex and species solely with respect to reproduction”

Intrasexual Selection

Sexual selection between members of the same sex ex. Male-male competition

Intersexual Selection

Sexual selection between members of the opposite sex ex. Female choice

Sexual Dimorphism

Sexual selection acting only on males more strongly than females causing a distinct differences between the sexes

Asymmetry of Sex

The fact that females require much more energy, resources, and time to pass on their genes in comparison to males

Gene Fixation

A gene becoming more prevalent up to 100% frequency, takes longer among larger populations

Bottleneck Effect

Something catastrophic randomly kills off many individuals in a population and only the genes of that small number of individuals remains in the gene pool

Founder’s Effect

Small part of a population drifts away from the rest randomly and creates a new population with only those individual’s genes

Emigration

Individuals leaving a population, subtracting from the gene pool

Immigration

Individuals entering a population, adding to the gene pool

Assertative Mating

When individuals with similar phenotypes are more likely to mate, favors homozygous genotypes

Disassortative Mating

When individuals with dissimilar phenotypes are more likely to mate, favors heterozygous genotypes

Inbreeding

Mating of genetically related individuals, favors homozygous genotypes

Speciation

Development of a new species

Phylogenetic Concept

Defining species based on their physical and genetic characteristics

Biological Concept

Defining species based on their ability to interbreed with each other

Reproductive Isolation

Two populations being unable to interbreed, often leading to speciation

Prezygotic Barriers

Things that prevent two individuals from mating, sperm does not fertilize the egg

Postzygotic Barriers

Things that prevent two individuals from creating viable offspring, even after fertilization

Geographic Barrier

Prezygotic barrier where populations are prevented from making contact by physical features such as a mountain or river

Ecological Barrier

Prezygotic barrier where species occur in the same area, but occupy different niches and use different resources, preventing them from interbreeding

Temporal Barrier

Prezygotic barrier where populations do not interbreed because they mate at different times of the day, in different seasons, etc.

Behavioral Barrier

Prezygotic barrier where the behaviors of a species do not attract another species, preventing them from interbreeding

Mechanical Barrier

Prezygotic barrier where the individuals have incompatible genitalia