Texts are in

“Basic Concepts in Biology”

Seventh edition

By Cecie Starr

USBN# 0-534-42029

1.5 Biological Inquiry

You are normally successful in your studies but for some reason in one class your average has slipped.

Q: What series of steps do you carry out to find the root of the problem?

No simply blaming the professor

is not an option!

1.5 Biological Inquiry

1. Research Problem2. Hypothesis 3. Prediction4. Experimental Tests5. Conclusion

– (confirm or refute the hypothesis)6. Repeat or revise

• Increased number to trials by peers further VALIDATES

7. Report test results

1.5 Biological Inquiry1. Research Problem2. Hypothesis 3. Prediction

4. Experimental Tests• Materials• Procedure

o Control group a placebo (1.6) to avoid ???o Experimental group (1.6)

Independent Variable (is the tested Dependent Variable

• Observations and data collection (graphs, charts, table)o Qualitative and Quantitative

• Analysis of Data 5. Conclusion

– (confirm or refute the hypothesis)6. Repeat or revise

• Increased number to trials by peers further VALIDATES 7. Report test results

1.6 Experimental Tests

• Controlled Experiment

• Open ended Experiments

• Field Experimental– Mimicry

All must avoid inner Biasness

For Today

• 16.3 Darwin Principles • 16.5 Individuals do not evolve, populations do• 16.6 Mutations• 16.7 Directional Selection• 16.8 Selection against or in favor of extreme

phenotypes• 16.9 Maintaining variations in a population• 16.10 Genetic Drift• 16.11 Gene flow

Upcoming

For Tonight

• Bubonic Reading

• Moth Simulation

9/17: Read

• Chapter 17.1, .3, .4, .6, .7, .8 .14

9/24 Test chapters 1, 16, 17

Chapter 16

What makes them similar?What makes them similar?

What makes them similar? What makes them similar? AdaptationsAdaptations

What is the same or similar????1. Comparative Anatomy (Homologous

structures)2. Comparative Biochemistry

1. DNA, RNA1. Similar genes

2. ENZYMES,

3. hormones

3. Comparative Embryology (embryonic development)

4. Comparative Cytology (cells)5. Geological Record

AdaptationsAdaptations

• An inherited trait or modification that improves the chance of Survival and reproduction of an organism in a given environment

For Now and Beyond

2/9/09

• Scientific method• Darwin and his principles• Finish chapter 16

– 16.1,

2/11/08

• Some of chapter 17– 17.1—17.6

2/6/08

• Assessment #1

16.1 Comparative Morphology and more

• Similarities and Differences among species gave rise to: Comparative Morphology– Study of body plans and structures among

groups of organisms • Comparative Anatomy• Comparative Cytology• Comparative Embryology• Comparative Biochemistry

16.7 Comparative Anatomy

16.9 Comparitive Biochemistry

What is not Evolution?

Types of EvolutionMicroevolution• changes in the gene pool of a

population over time which result in relatively small changes to the organisms in the population

• Examples:– change in a species’ coloring or

size. – Mosquito ability to detect CO2 – Insect/Bacteria resistance to

biocides.

• Accepted by religions as not being contradictory to their faiths

Macroevolution• changes in organisms

which are significant enough that, over time,

• the newer organisms would be considered an entirely new species. – Forming a new higher

organism

• NOT ACCEPTED

16.1 Alfred Wallace and his catalogs

• Comparative Morphology: The study of body plans and structures among groups of organisms. – Father of Biogeography– Saw patterns in the geographic distribution of species– Thought something shaped populations

• Why are they the so similar?

Rhea of SA Ausi Emu African Ostrich

16.2 New Theories

• George Cuvier: saw abrupt changes in fossils. (mass extinctions)– Catastrophism: sudden changes in geologic

forces shaped the earth’s surface • NOT SUPPORTED • Apposed by gradualism

16.2 New Theories

• Jean Batiste Lamark – Inheritance of Acquired Characteristics

• hereditary mechanism by which changes in physiology acquired over the life of an organism (such as muscle enlarged through use) are purportedly transmitted to offspring

How would Lamark explain taller How would Lamark explain taller current day Giraffes then those found in current day Giraffes then those found in

the fossil record? the fossil record?

Darwin• Cambridge Degree in Theology / Naturalists• 1859 The Origin of Species by Means of Natural Selection,1859 The Origin of Species by Means of Natural Selection,• Or Or The Preservation of Favored Races in the Struggle for The Preservation of Favored Races in the Struggle for

LifeLife

• Charles Darwin devised a theory of evolution based on Charles Darwin devised a theory of evolution based on variation and natural selection variation and natural selection

• Included in hid theory were five main ideas:Included in hid theory were five main ideas:1.1. Overproduction Overproduction 2.2. CompetitionCompetition3.3. Survival of the Fittest Survival of the Fittest 4.4. Reproduction Reproduction 5.5. SpeciationSpeciation

This would be Darwin’s View of Lamark’s giraffes .

16.5 Radioactive Dating

16.5 Radioactive Dating

• The Uranium is trapped in the rock as it forms and over time as the Uranium decays, it is replaced by non-radioactive Lead.

• ½ life of Ur is 704 million years

16.5 Radioactive Dating

• Theory of Geologic Time:

16.6 Pangea

Super continenteventually Forming

Gondwana and

Laurasia

16.6 Pangea

140 mill 120 mill

finito per stasera

Please grab your Journals. Rubrics found within

17.1 Five reasons for VariationsWhy you are not like your Folks

1. Population: is one group of the same species in a specific area.

2. Gene Pool: all of the genetic resources in a given area.

Chapter 17 Processes of Evolution

The Ole-Gene Pool Excuse

17.14 Adaptation to What?

Adaptation” has many meanings:1. Short term adaptation: A pine tree not growing

as tall in a windy spot than pines in a calm spot.

• NOT INHERITABLE

2. Evolutionary Adaptation: an adaptive trait, inherited form or function that improves ones chances of survival and reproduction in a given environment.

17.14 Adaptation to What?

1. Salt tolerant tomatoes

2. Rodents surviving the desert with minimal water

3. No polar bears in the desertBUT what about The Llama of the Andes and Camels?

17.1 “Indys” Don’t but Pops DO!• Morphological: Form

• Dimorphic: two variations– Male vs. Female coloration

• Polymorphisms: Three or more alleles (Variations) within a population– Blood types, Labrador retrievers, eye color

17.1 “Indys” Don’t but Pops DO!

• Chromosomes: a unit of heredity, DNA

• Phenotypes: Physical representation of a gene

• Genotype: Genetic expression on a gene

All due to Genes

17.1 “Indys” Don’t but Pops DO!

Genes: genetic traits, •Gene for Tongue rolling•Gene for Hair color •Gene for Eye color

–Alleles: variation of genes,»Blue, Brown, green, hazel

•Leads to variations in phenotypes

17.1 Indys Don’t Pops DO

The Gene Pool: all of the genes in a population

Fill in your own joke.

17.1 Five reasons for VariationsWhy you are not like your Folks

1. Gene Mutations • produces new alleles

2. Crossing over • New combination of alleles w/i Sperm and egg• Chromosomes break and exchange information

3. Independent Assortment: • Never can predict which chromosomes will pair up• Sperm and egg

4. Fertilization • Combines alleles from two parents

5. Change in Chromosome Number or Structure• Loss, duplication, repositioning of genes.

17.1 Mutations Revisited

• Mutation Rate probability between replication

Mutations are random and the phenotypic outcome may be neutral, beneficial, harmful, or even lethal to the individual depending on other interactions.

• Neutral, Beneficial, lethal mutations• Body Structure and Collagen???pg266• Rethink Giraffe Neck????

17.1 Mutations Revisiteda. Lethal mutation is an expression of a gene that

results in death.

b. Neutral mutations, whether or not they are expressed in phenotype, have no effect on survival and reproduction. FOR NOW

c. Beneficial mutations are those that bestow survival advantages.

Lethal Genes seem to take care of themselves

17.3 Types of Selection

1.Directional Selection 2.Stabilizing Selection3.Disruptive Selection

17.4 Directional Selection• How could any dark morphed pocket mice

survive in the Arizona’s Sonoran Desert ?

17.3 Types of Selection• Directional: range of variations for a trait

shifts in one direction.

17.3 Types of Selection

• Directional: range of variations for a trait shifts in one direction. – Forms at one end of a Phenotypic range

become more common then midrange forms• Pesticide Resistance• Antibiotic Resistance

Response to change in the environment

THE KEY IS THE ENVIRONMENT

17.4 Directional

Stabilizing Selection when selection favors the intermediate trait value over

the extreme values.

Disruptive SelectionDisruptive Selection

when selection favors the extreme trait values over the when selection favors the extreme trait values over the intermediate trait values. In this case the variance intermediate trait values. In this case the variance

increases as the population is divided into two distinct increases as the population is divided into two distinct groups.groups. Disruptive selection plays an important role in

speciation.

Using your reading from this week end what Using your reading from this week end what principle is demonstrated below? principle is demonstrated below?

17.6 Maintaining Variations 17.6 Maintaining Variations

in a Population, Sexual dimorphism in a Population, Sexual dimorphism

• Two different morphologies. male and female– phenotypes or secondary sexual characteristics.

• Sexual selection is based on any trait that gives the individual a competitive edge in mating and producing offspring.

• Many times the males compete for the privilege of mating with certain females but at other times the females are the agents of selection when they pick their mates.

• Through nonrandom mating, alleles for preferred traits increase.

• This leads to increased sexual dimorphism

Balanced Polymorphism

• Balanced polymorphism (having many forms) is the maintenance of two or more forms of a trait in fairly steady proportions over time.

• Greater Genetic Variation leads to greater Biodiversity (Its Healthier)

– Ex:It is now known that heterozygous individuals are more resistant to the protozoan that causes malaria.

– They survive in greater numbers than the homozygotes This occurs when nonidentical alleles are maintained at frequencies greater than one percent.

• Malaria• Sickle-cell anemia • Heterozygotes HbS/HbA, comprise about one third of the pop

17.7 Genetic Drift- The Chance Changes

• The random change in allele frequencies over time, due to chance occurrences alone.

• More significant in small populations. – “Easier to spread”

• Sampling error Rule of Probability– 50 coin flips, 500 flips

– explains why the chance of any given allele becoming more or less prevalent is more pronounced in a small population.

• Fixation means that one kind of allele remains at a specified locus in a population.

17.8 The flow of Genes

• Q: What is the difference between Immigration and Emigration?

• A: The Gene Flow: physical flow of alleles between tow or more populations.– Immigration: population gains alleles– Emigration: population loses alleles

Caveman DNA hints at map of migration

• Oldest American genetic sample reveals early New World frontiers.

• The oldest sample of human DNA ever isolated in the Americas is providing a glimpse of how people spread across the land masses. The DNA was extracted from teeth, more than 10,000 years old, found in a cave on the northern tip of Prince of Wales Island, off southern Alaska

Massive Genetic Study Supports "Out of Africa" Theory

• Two big genetic studies confirm theories that modern humans evolved in Africa and then migrated through Europe and Asia to reach the Pacific and Americas.

Genetic Drift- The Chance Changes

Bottleneck Effect• This is a severe reduction in population size that

causes pronounced drift. – Contagious disease, habitat loss, hunting

• For example, the elephant seal population was hunted down to just 20 individuals.

• Then the population rebounded to 130,000.

• In bottlenecks, some stressful situation greatly reduces the size of a population leaving a few (typical or atypical) individuals to reestablish the population.

16.10 Bottlenecking Examples of Genetic Drift: elephant seals, cheetahs, humans (amish)

The Founder Effect• Genetic outcomes also can be unpredictable after a

few individuals establish a new population– Seedling on birds– Acorns and Blue Jays

• In the founder effect, – a few of these original founders had a mutation, the gene

defect would then be passed on to their descendants for generations to come.

• Amish, cultural isolation • Selective Inbreeding• Geographic Isolation????

The Founder Effect• Genetic outcomes also can be

unpredictable after a few individuals establish a new population– Seedling on birds

• It is the effect of drift when a small number of individuals start a new population.

• By chance, allele frequencies of founders may not be the same as those in the original population.

Fine’

16.3 Darwin's Inquiry1. Research Problem:

• Why the echinoderms do not over populate?

2. Hypothesis: • Nature has checks and balances

3. Prediction:4. Experimental Tests

• Observations• Populations have inherent reproductive capacities• No population can survive w/o competition of resources

• Analysis of Data • Darwin's Concept of Competition

5. Conclusion 6. Repeat or revise

• Consistent patterns within his data

7. Report test results (On the Origin of Species)

17.7 Genetic Drift- The Chance Changes

• Genetically modified fruit makes the News

http://www.gmoinfo.ie/papaya.php

16.10 Bottlenecking

GM papayas Yummy goodness or DestroyerOf the Human Genome?

Using the key terms from 16.9-16.11

Iiwi pronounced “EEVEE

16.10 Bottlenecking

Iiwi(Vestiaria coccinea)

'I'iwis are some of the most spectacular birds found in the Hawaiian Islands, with their long, decurved bills and striking red and black feathers. This species is still relatively common in high-elevation forests on the island of Hawaii, and has smaller populations on four other main islands; but its high susceptibility to avian malaria could make it extremely vulnerable to the future introduction of mosquitoes capable of surviving at high elevations.

http://www.audubon2.org/webapp/watchlist/viewSpecies.jsp?id=108