BIO181

Hierarchy Of Organization

Atoms
Molecules
Organelles
Cells
Tissues
Organs
Organ Systems
Organisms

Characteristics of Life

Has Cells Can

Reproduce

Takes in, uses and transforms energy

Interacts with environment and responds to stimuli

Grows and Develops

Adapts and Evolves

Has Movement

Needs Water

Prokaryote Reproduction

One way transfer of DNA from donor to recipient

Eukaryote Reproduction

DNA from two individuals combines to make third individual; new combinations possible

Metabolism

Chemical reactions involved in converting energy from environment and using it in processes essential to growth, repair, and reproduction

Cells

The basic unit of structure and function Two Types: Prokaryotic and Eukaryotic

Reproduction

Life is continued through DNA, RNA; life comes from life

Homeostasis

Maintains a constant internal environment, regardless of changing external environment

Movement

Basic property of cells

Functions of Water

Surrounds All Cells Is Inside all cells Helps maintain stable body temperature Transports Materials

Observation

A statement describing a fact Uses one or more of the 5 senses
Describes something as it appears

Inference

A statement based on interpretation of the facts
Makes an explanation for the observation Cannot be directly observed

Induction

Gathering together bits of date, then formulating a generalization which explains all of them
SPECIFIC TO GENERAL

Deduction

Begins with a generalization, then makes predictions based on the generalization, then performs an experiment/finds data
GENERAL TO SPECIFIC

Discovery Science

Collects and analyzes data then describes observations Not hypothesis driven

Scientific Method(not listing steps)

A series of steps used to answer questions logically Hypothesis driven Usually tested with a controlled experiment Results should be repeatable

5 Major Steps to the Scientific Method

1. Make Observations
2. Formulate Hypothesis
3. Design and Perform controlled experiment
4. Analyze results
5. Draw conclusions(accept or reject hypothesis) Present results

Characteristics of a Hypothesis

1. Must be testable
2.Must be falsifiable

Control Group

Used as a baseline measure, identical to variable group except does not receive treatment in question

Variable

What is altered, measures or manipulated in an experiment

Independent Variable

What is manipulated that the experimenter has control over
(only 1 per experiment)

Dependent Variable

What is observed and/or measured, changes based on the independent variable

Correlation

Two variables that vary together predictably

Controlled Variable

Anything that could influence the depends variables, stay the same for all subjects in the experiment.

Theory

Established explanations, extremely likely to be true Require a lot of support and hypothesis must be supported repeatedly

Pseudoscience

Science that is not falsifiable or cannot be tested

Junk Science

Faulty, insufficient, unreliable or biased data (evidence ignored or unconfirmed to further an agenda)

Linnaeus

Created Classification system- highlighted differences among organisms

Buffon

Quietly suggested that species change over generations, and that new world animals had "degenerated" from old world forms

Lamarck

Discovered acquired characteristics(traits passed on through use or disuse

Acquired Characteristics

Traits passed on through use or disuse

Malthus

Created idea that populations grow until they reach limits on size

Darwin & Wallace

Created the theory of natural selection, but Darwin published his findings first and git the credit.

Creationism/Creation Science

Rejects the theory of evolution and the idea that one species over time can become another species

Intelligent Design

Rejects that natural law and chance alone can explain the diversity of life on earth, arguing instead that it is the result of a purposeful scheme of some higher power

Evolutionism

Accepts the Darwinian argument that natural selection and environmental factors combine to explain the diversity of life on earth, and may or may not believe that evolution is the way in which a Devine being has chosen to work in the world.

Variation and Competition

Individuals Vary, some variations are heritable Resources are Limited Organisms with the most favorable traits for that environment have the most reproductive success, and those traits are passed on to the next generation

Natural Selection

Forces of nature select individuals with traits that favor reproductive success

Sexual Selection

Individuals with faulty characteristics are unattractive to other members of their group because they appear weak and thus do not reproduce

Adaptation

A populations characteristics change over time Happens with natural selection over time

Is natural selection goal oriented?

No, it is a process.

Hominin

Direct ancestors to humans, walk on 2 legs

Pseudogenes

Genes inherited from ancestors that are no longer used or expressed

Atavism

When vestigial traits or pseudogenes are expressed in a specific individual

Vestigial Structures/Traits

Traits/Structures that were once necessary but are no longer are

Evidence for Evolution

1. Fossils
2. Vestigial Structures
3. Breeding/Artificial Selection
4. Comparative Anatomy(Homologous and Analogous traits)
5. Biochemical Evidence (DNA, Proteins)
6. Embryology
7. Distribution of Species

Homologous Traits

Similar traits that were inherited from the same ancestor
A result of Divergent Evolution

Analogous Traits

Similar traits that evolved through same functions A result of convergent evolution

Convergent Evolution

The independent evolution of similar features in species of different periods in time

Divergent Evolution

The process of one species branching into multiple species that begin to evolve seperately

Steps of Evolution

1. Variation by Mutation of Recombination
2. Changes in frequencies of alleles and genotypes

Microevolution

Changes in a population's gene pool from one generation to the next

Population

Same species, same place, same time

Species

Can breed and produce fertile offspring

Genetic Equilibrium

No change occurs in gene frequency

Factors that cause Microevolution

1. Mutation/New Genetic Variation
2. Evolutionary Mechanisms/Alteration of existing genetic variation

Mutation

Unpredictable change in DNA- could be good or bad or neutral Source of new genetic variation Only mutations in gametes are inherited

Epigenetics

The study of how the environment turns genes on or off

Evolutionary Mechanisms

1. Genetic Drift
2. Gene Flow
3. Natural Selection
4. Nonrandom Mating

Genetic Drift

Allele frequencies in small populations change by random chance events

Founder Effect

New habitat, few individuals establish new population

Bottleneck Effect

Drastic population reduction causes less genetic variation

Gene Flow

Migration of fertile individuals, or transfer of gametes from one population to another

Macroevolution

Evolutionary changes that create new species and groups of species Occurs by accumulation of microevolutionary changes

Phylogenetic
(Species Concepts)

Species are identified by having a unique combination of traits Historically used physical traits, now can use DNA sequences

Biological
(Species Concepts)

A group of individuals whose members have the potential to interbreed with one another in nature to produce viable, fertile offspring but cannot successfully interbreed with members of other species

Ring Species

A series of geographically neighboring populations that are closely related. They are related so closely that they interbreed. Members of populations near the ends of territorial spread are unable to interbreed.

Evolutionary
(Species Concepts)

A species is derived from a single lineage that is distinct from other lineages and has its own evolutionary tendencies and historical fate

Ecological

Each species occupies an ecological niche If two organisms are very similar, their needs will overlap, which results in competition

Reproductive Isolating Mechanisms

Process through which natural selection keeps two groups separate Prevents interbreeding and thus the development of one single species

Prezygotic Isolating Mechanisms

Reproductive Isolating Mechanisms that happen before fertilization

Temporal Isolation

Species reproduce at different times

Behavioral Isolation

Mating rituals/actions are very different

Mechanical Isolation

It don't fit

Gametic Isolation

The sperm and egg are unable to connect

Ecological/Habitat Isolation

Species live in different areas

Postzygotic Isolating Mechanisms

Reproductive Isolating Mechanisms that take place after fertilization

Zygotic Mortality/Inviability

Hybrid zygotes fail to develop

Hybrid Sterility

Hybrids cannot produce gametes/reproduce

Hybrid Breakdown

Weak, low fitness, high mortality rate

Anagenesis

Small, progressive changes in a single species over long periods Sequences of species, no increase in the # of species

Cladogenesis

A cluster of species all derived from a single common ancestor

Patterns of Speciation

How microevolution results in macroevolution

Allopatric Speciation

Geographical isolation results in new species; gene flow between populations slows or stops Most common way cladogenesis occurs

Parapatric Speciation

Reproductive isolation evolves in neighboring populations that share small zones of contact and exhibit modest gene exchange Genetic divergence arises largely through natural selection

Sympatric Speciation

New species evolves in same area of parental species

Punctuated Equilibrium

Abrupt changes cause evolution

Gradualism

Evolution occurs slowly in small changes over time

Community

All of the populations in a particular area

Ecosystem

Community and Abiotic Factors

Biosphere

Entire realm in which organisms take place

Species

A group of interbreeding organisms that produce fertile offspring and that do not ordinarily Breed with members of other groups

Characteristics of Population

1. Density
2. Dispersion
3. Growth

Density Equation

Number of individuals divided by Unit Area

Dispersion

Pattern of spacing within geographic boundaries of population

Growth

Depends on biotic potential, leads to exponential growth

Biotic Potential

The fastest possible reproductive rate possible for a population under ideal conditions, differs from one species to another

Population Growth

The change in the number of individuals in the population per unit time

Population Growth (formula)

(births-death) + (immigrants-emmigrants)/ total population

Limiting Factors

Factors that limit the growth of a species and determine the carrying capacity