How have you, AND will, you EVOLVE??? TRANSFORMATION TUESDAY! How have you, AND will, you EVOLVE???

Ch.5 - Evolution and Biodiversity “Each species here today represents a long chain of evolution and plays a unique ecological role (niche) in the earth’s communities and ecosystems.”

5-1 Origins of Life HOW DO WE KNOW??? Protocells TED Talk Chemical Evolution – organic compounds and systems of chemical reactions formed the first cells. (took about 1 billion years!) Biological Evolution – change from single celled prokaryotes single celled eukaryotes multicellular organism HOW DO WE KNOW??? Most left behind fossil records that give us physical evidence of past organisms and their internal structures. Records are incomplete, however, and actually only represent about 1% of all species ever lived.

5-2 Evolution and Adaptations Evolution – change in a POPULATION’S genetic makeup over successive generations (not individuals!) Theory of Evolution - all species descended from earlier, ancestral species Macroevolution Microevolution Long-term, large scale changes from 1 ancestral species to another where older species is lost through extinction. Small genetic changes in a population’s gene pool that are past on to offspring.

Which picture represents microevolution? Macroevolution?

Past organisms’ fossil records Relative vs. Radiometric dating

WHAT IS THE MAJOR CAUSE OF EVOLUTION?

Genes-area/location on a chromosome (within DNA) that codes for a particular protein; proteins then give particular phenotype/behavior Alleles- different version of the SAME GENE Mutations – environmental or random; harmful or beneficial Differentiating between DNA, gene, chromosomes 5-2 Changes in a Gene pool

Mutations create genetic diversity and new combinations of alleles

Beneficial and Lethal Mutations

Natural Selection When individuals in a population have certain genetic traits that enhance their ability to survive and pass on these advantageous traits to their offspring. Adaptation- heritable trait that enables the organisms to better survive under environmental conditions.

When faced with changing environmental conditions a species will either: 1) adapt through natural selection 2) migrate to areas with more favorable conditions 3) become extinct!

MICROEVOLUTION Summary… Occurs when genes mutate individuals are selected population change (evolve).

Coevolution Examples: Bats and moths (echolocation) Humans and Lactase Interactions between 2 populations of different species over a long period of time can lead to changes in their gene pools, like a evolutionary contest of who can produce the most offspring. Examples: Bats and moths (echolocation) Humans and Lactase

5-3 Ecological Niches & Adaptations Niche– specific role in an ecosystem (occupation) Includes: adaptive traits range of tolerance for physical/chemical conditions (temperature/H2O availability) Types/amount of resources specie uses (food, space,etc) How it interacts with nonliving/living components in the ecosystem Role specie plays in energy flow and matter cycling in the ecosystem. HABITAT- physical location where organism lives (address)

5-3 Ecological Niches & Adaptations Fundamental Niche – full potential range of physical, chemical, and biological conditions and resources a species could theoretically use if there was no t direct competition from other species. Realized Niche- specie only occupies part of its fundamental niche to survive and avoid competition video Broad vs. Narrow niches = Generalists vs. Specialists

Fitness = reproductive success, not strongest! Limits to Adaptations Genetic trait that leads to an adaptation to changes in the environmental condition must already be present in the gene pool. If present, adaptation is limited by reproductive rate. (humans would take thousands to millions of years to adapt!) Fitness = reproductive success, not strongest!

5-4 Speciation, Extinction, and Biodiversity Allopatric speciation Geographic isolation Reproductive isolation (Physical barrier) (no longer produces fertile offspring) Sympatric Speciation Mutation or changes in behavior no longer allows interbreed in close living species (insects)

Mechanisms for Speciation ALLOPATRIC SPECIATION SYMPATRIC SPECIATION Squirrel species of Grand Canyon A. harrisi A. leucurus

Extinction 99.9% of all species that ever existed are now extinct. Background extinction- species disappear at a low rate Mass extinction and mass depletion Extinctions create new opportunities for other species. Adaptive radiation sets in as new species adapt to fill vacated ecological niches in changed environments.

Human Activities are Decreasing Biodiversity Richest areas of biodiversity- tropical forests, coral reefs, and wetlands

5-5 What is the future of evolution? Artificial Selection Selective breeding Genetic engineering Genetically modified organisms (GMO’s) or transgenic organisms Gene splicing Biopharming- using genetically engineered animals to produce a product for human use (hormones, vaccines, antibodies, etc.) Bioethics- governmental regulations and control

Genetic Engineering Recombinant DNA Hepatitis B vaccine produced in bananas (biopharming)

p. 142 FRQ #2 Drug resistant bacteria Friedland and Relyea Textbook p. 142 FRQ #2 Drug resistant bacteria