The Science of BiologyThe Science of BiologyChapter 1Chapter 1

Properties of LifeProperties of Life

Basic characteristics of living organismsBasic characteristics of living organisms

– cellular organizationcellular organization

Properties of LifeProperties of Life

--sensitivity--sensitivity

Properties of LifeProperties of Life

– --growth, development, and reproduction--growth, development, and reproduction

Properties of LifeProperties of Life

--energy utilization--energy utilization

Properties of LifeProperties of Life

--adaptation--adaptation

Properties of LifeProperties of Life

– --homeostasis--homeostasis

Hierarchical OrganizationHierarchical Organization

--Atoms--Atoms

Hierarchical OrganizationHierarchical Organization

--molecules--molecules

Hierarchical OrganizationHierarchical Organization

--macromolecules--macromolecules

Hierarchical OrganizationHierarchical Organization

--organelles--organelles

Hierarchical OrganizationHierarchical Organization

--cells--cells

Hierarchical OrganizationHierarchical Organization

--tissues--tissues

Hierarchical OrganizationHierarchical Organization

--organs--organs

Hierarchical OrganizationHierarchical Organization

--organ systems--organ systems

Hierarchical OrganizationHierarchical Organization

--populations--populations-----species-----species

Hierarchical OrganizationHierarchical Organization

--biological community--biological community

Hierarchical OrganizationHierarchical Organization

--ecosystem--ecosystem

Hierarchical OrganizationHierarchical Organization

--biosphere--biosphere

ReasoningReasoning

Deductive reasoningDeductive reasoning– Apply general principles to predict specific Apply general principles to predict specific

resultsresults

ReasoningReasoning

Inductive reasoningInductive reasoning– Use specific observations to construct general Use specific observations to construct general

principlesprinciples

How Science Is DoneHow Science Is Done

All science begins with an All science begins with an observation.observation.

How Science Is DoneHow Science Is Done

AA hypothesis hypothesis is a suggested explanation is a suggested explanation that accounts for an observationthat accounts for an observation..

How Science Is DoneHow Science Is Done

An An experimentexperiment is used to test a is used to test a hypothesis, and/or eliminate one or more hypothesis, and/or eliminate one or more multiple hypothesesmultiple hypotheses..

How Science Is DoneHow Science Is Done

In a In a controlled experimentcontrolled experiment, all , all variablesvariables, , but one, are kept constant.but one, are kept constant.

How Science Is DoneHow Science Is Done

PredictionsPredictions should be developed before should be developed before the experiment is conducted in order to the experiment is conducted in order to test the validity of the hypothesis.test the validity of the hypothesis.

How Science Is DoneHow Science Is Done

TheoriesTheories

A A theorytheory is: is:– a proposed explanation for a natural a proposed explanation for a natural

phenomenon.phenomenon.– the body of interconnected concepts, the body of interconnected concepts,

supported by scientific reasoning and supported by scientific reasoning and experimental evidence.experimental evidence.

solid ground of sciencesolid ground of science

ResearchResearch

Basic researchBasic research is used to extend the is used to extend the boundaries of current knowledge, and boundaries of current knowledge, and provides the scientific foundation used in provides the scientific foundation used in applied researchapplied research..

ResearchResearch

Results undergo Results undergo peer reviewpeer review in scientific in scientific journals.journals.

Comparisons of envelope through 5B sequences of infectious bronchitis coronaviruses indicates recombination occurs in the envelope and membrane genes.Brooks JE, Rainer AC, Parr RL, Woolcock P, Hoerr F, Collisson EW.SourceDepartment of Veterinary Pathobiology, College of Veterinary Medicine, Texas A&M University, College Station, TX 77843, USA.

ResearchResearch

Results undergo Results undergo peer reviewpeer review in scientific in scientific journalsjournals..

Molecular evolution of adaptive and drought resistance related genes Molecular evolution of adaptive and drought resistance related genes in four Southern pines from subsection Australesin four Southern pines from subsection Australes. . Koralewski, Tomasz; Brooks, Judy; Krutovski, Konstantin.Koralewski, Tomasz; Brooks, Judy; Krutovski, Konstantin.Submitted June 15, 2012.Submitted June 15, 2012.Under review by Under review by Canadian Journal of Forest ResearchCanadian Journal of Forest Research..Source: Texas A&M University, Dept. of Ecosystem Science and Source: Texas A&M University, Dept. of Ecosystem Science and Management (ESSM)Management (ESSM)

ResearchResearch

Results must be reproducible.Results must be reproducible.

Charles DarwinCharles Darwin

Served as naturalist on mapping Served as naturalist on mapping expedition around coastal South America.expedition around coastal South America.

Darwin’s VoyageDarwin’s Voyage

Charles DarwinCharles Darwin

Argued operation of natural laws produced Argued operation of natural laws produced change over time, change over time, evolutionevolution..

Charles DarwinCharles Darwin

explained by explained by natural selectionnatural selection

Natural SelectionNatural Selection

Charles DarwinCharles Darwin

species are not immutablespecies are not immutable

Charles DarwinCharles Darwin

Darwin’s EvidenceDarwin’s Evidence

Fossils of extinct organisms (armadillos) Fossils of extinct organisms (armadillos) were similar to modern species.were similar to modern species.

Darwin’s EvidenceDarwin’s Evidence

Characteristics of similar species varied Characteristics of similar species varied from place to place.from place to place.

Darwin’s EvidenceDarwin’s Evidence

– gradual change of organismal lineagesgradual change of organismal lineagesorganisms on young volcanic islands organisms on young volcanic islands resembled those on mainland coastresembled those on mainland coast

Large ground finch (seeds)Cactus ground finch

(cactus fruits and flowers)

Vegetarian finch (buds) Woodpecker finch (insects)

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Darwin and MalthusDarwin and Malthus

Thomas Malthus (Essay on the Principle Thomas Malthus (Essay on the Principle of Population) pointed out populations of of Population) pointed out populations of organisms tend to increase geometrically.organisms tend to increase geometrically.

Geometric and Arithmetic Geometric and Arithmetic ProgressionProgression

Darwin and MalthusDarwin and MalthusUnchecked populations should lead to population explosions, but most remain fairly constant between years

Darwin and MalthusDarwin and Malthus

Only a limited number of individuals survive

Darwin and MalthusDarwin and Malthus

Darwin suggested individuals with superior Darwin suggested individuals with superior physical or behavioral attributes are more physical or behavioral attributes are more likely to survive and reproduce than those likely to survive and reproduce than those without such attributes.without such attributes.

Darwin and MalthusDarwin and Malthus

– SelectionSelectionartificialartificial - domesticated breeds - domesticated breeds

Darwin and MalthusDarwin and Malthus

natural natural - organisms in the wild- organisms in the wild

Darwin and WallaceDarwin and Wallace

Alfred Russel Wallace independently and Alfred Russel Wallace independently and almost simultaneously developed same almost simultaneously developed same idea. idea.

Homology Among Vertebrate Homology Among Vertebrate LimbsLimbs

Unifying Themes of ScienceUnifying Themes of Science

Cell theoryCell theory– All living organisms are made of cells, and All living organisms are made of cells, and

all living cells come from other living cellsall living cells come from other living cells..

Unifying Themes of ScienceUnifying Themes of Science

Molecular basis of inheritanceMolecular basis of inheritance– DNA encodes genes which make-up DNA encodes genes which make-up

and control living organismsand control living organisms..

Unifying Themes of ScienceUnifying Themes of Science

– Life-forms have developed varying characteristics Life-forms have developed varying characteristics to adapt to varied environments.to adapt to varied environments.

– Some characteristics of earlier organisms are Some characteristics of earlier organisms are preserved and passed on to future generations.preserved and passed on to future generations.