EVOLUTION BY MEANS OF NATURAL SELECTION Ch. 10 & 15

1. What adaptations does this organism have? 2. How did these adaptations evolve? 3. How do they enable the organism to survive in its environment?

They have long legs and neck, long, tough, prehensile tongue, and leathery mouth for food gathering. Their coloration is protective. They are tall with good eyesight for watchfulness. Giraffes have high blood pressure (240/160) for pumping blood to the brain. Long neck for reaching its food source (leaves)

The Peppered Moth 2 variations of Moths: light and dark 2 variations of Moths: light and dark Prior to the industrial revolution – white was favored Prior to the industrial revolution – white was favored Post-industrial revolution – black (peppered) became more common. Post-industrial revolution – black (peppered) became more common. Why? How do predators and environments drive evolution? Why? How do predators and environments drive evolution?

The Industrial Revolution polluted the environment, raining soot down on the countryside. As a result, white moths became highly visible on the now blackened tree trunks. Black moths such as the peppered moth (which had previously been quite rare), suddenly had a competitive advantage. They were well camouflaged on black tree trunks, and their numbers grew exponentially. By the early twentieth century, they were the dominant moth form in polluted areas of the UK.

EVOLUTION BY MEANS OF NATURAL SELECTION 5 Principles

1. Variation All species have variations All species have variations Variation is the raw material for natural selection Variation is the raw material for natural selection Ex: Variations in giraffes

2. Struggle for Existence Organisms produce more offspring than can survive. Organisms produce more offspring than can survive. The environment produces struggles organisms must surpass to The environment produces struggles organisms must surpass to survive survive

3. Only some survive to reproduce Some are better able to survive and reproduce (pass on their genes) Some are better able to survive and reproduce (pass on their genes)

4. Natural selection results in genetic change Each generation contains an increased proportion of individuals with traits that promote survival and reproduction. Each generation contains an increased proportion of individuals with traits that promote survival and reproduction. What are some alleles that a successful giraffe might have? What are some alleles that a successful giraffe might have? Neck length Neck length Leg length Leg length

5. Species adapt to their environment Selection makes a population better suited to it’s environment. Selection makes a population better suited to it’s environment. The environment determines The environment determines the direction of genetic change. the direction of genetic change.

What drives the Natural Selection? *When *When is a mutation is a mutation a ‘good’ mutation? a ‘good’ mutation?

Mimicry and Coloration

Driving Force of Evolution: Competition Limiting factors – any condition of the environment that limits the size of a population Limiting factors – any condition of the environment that limits the size of a population Carrying capacity – The number of organisms that can be supported by a particular ecosystem Carrying capacity – The number of organisms that can be supported by a particular ecosystem Overpopulation - the condition of having a population so dense as to cause environmental deterioration, an impaired quality of life, or a population crash Overpopulation - the condition of having a population so dense as to cause environmental deterioration, an impaired quality of life, or a population crash

RAPID GROWTH “Pyramid” Rapid, Slow or Negative Population Growth?

SLOW GROWTH “Boxy” “Pear Shaped” “Middle Bulge” Rapid, Slow or Negative Population Growth?

Slow vs Fast Which is Fast, which is Slow Growth?

Fast to Negative 1999 Rapid, Slow or Negative Population Growth?

Symbiosis A close, long-term association between two or more species. 3 types: Mutualism – all participating organisms benefit Mutualism – all participating organisms benefit Commensalism – one species benefits, the other is unharmed Commensalism – one species benefits, the other is unharmed Parasitism – one species benefits, the other is harmed (usually not killed – why?) Parasitism – one species benefits, the other is harmed (usually not killed – why?)

Factors Affecting Population Changes Birth Rate Birth Rate Death Rate Death Rate *usually determine the size of the base, but also affected by Migration Immigration- movement INTO a population (migrant workers/child bearing age) Immigration- movement INTO a population (migrant workers/child bearing age) Emigration- movement OUT of a population Emigration- movement OUT of a population

Evidence of Evolution Fossils Fossils Bones, casts, footprints, amber, ice Bones, casts, footprints, amber, ice Homologous structures Homologous structures Comparative embryology Comparative embryology Vestigial structures Vestigial structures Biochemical (DNA and amino acids) Biochemical (DNA and amino acids)

~3.5 Bill yrs Oldest fossils/p rok Cyanobacteria Endosymbiosis Land Plants, Animals 200,000- Homo Sapiens (11:59:30)

Primate Evolutionary Tree

Review timelines lab assignment and completed timelines in the classroom Review timelines lab assignment and completed timelines in the classroom NOTE: 1 Meter stick = 1 Billion Years NOTE: 1 Meter stick = 1 Billion Years 4.6 Billion (Age of Earth) = ? 4.6 Billion (Age of Earth) = ? 10 cm = ? cm = ? mm = 1 million years 10 cm = ? cm = ? mm = 1 million years Evolutionary Timelines LAB: Textbook…

Opening of ‘adaptive zones’ – allowed for new species to develop Mass Extinction

Earth’s Geologic History Earth’s Geologic History

Classification of a Leopard

Anthropoids: Monkeys, Apes, Humans ~45mya Africa/Asia Hominoids: Apes, Humans ~23-25 mya Hominids: Humans & ancestors ~6-7mya PROSIMIANS- “before primates”

Advanced brain Advanced brain Eyes forward- stereoscopic vision/depth perception Eyes forward- stereoscopic vision/depth perception Color vision Color vision Acute hearing Acute hearing Dental formula- same #, type, arrangement of teeth Dental formula- same #, type, arrangement of teeth Long slender limbs/rotate freely at hips/shoulders Long slender limbs/rotate freely at hips/shoulders 5 flexible digits with flattened nails/not claws 5 flexible digits with flattened nails/not claws Opposable thumbs Opposable thumbs Complex social behaviors Complex social behaviors Usually 1 offspring at a time; longer parental care Usually 1 offspring at a time; longer parental care Characteristics of Primates

Human Evolution: Australopithecines Homo habilis Homo erectus Homo sapiens

The remains or evidence of any creature or plant that once lived on the Earth. The remains or evidence of any creature or plant that once lived on the Earth.

Fossils Fossils are often found in sedimentary rock, which is formed from layers of silt and sand covering dead organisms. Fossils are often found in sedimentary rock, which is formed from layers of silt and sand covering dead organisms. The oldest are found on the lowest layers, youngest in the upper layers The oldest are found on the lowest layers, youngest in the upper layers

Fossils in Amber (Hardened Tree Sap)

Homologous Structures Homologous Structures Similar structure and anatomical position (but not necessarily the same function) in different organisms suggesting a common ancestry or evolutionary origin (e.g. wings of bats and arms of humans are homologous).

How Many Neck Vertebrae?

Comparative Embryology the more closely related any two species are, the more similar their development

Vestigial Structures structures or organs that seem to serve no useful function Organisms having vestigial structures probably share a common ancestry with organisms in which the homologous structure is functional

Biochemical/DNA Evidence The closer the DNA sequences of 2 organisms are, the more closely related they are. The closer the DNA sequences of 2 organisms are, the more closely related they are. Ex. Humans and chimps have DNA that is 99% identical Ex. Humans and chimps have DNA that is 99% identical

Dating the Age of Fossils Carbon-14 dating is a way of determining the age of certain archeological artifacts of a biological origin up to about 60,000 years old. It is used in dating things such as bone, cloth, wood and plant fibers that were created in the relatively recent past by human activities. Carbon-14 dating is a way of determining the age of certain archeological artifacts of a biological origin up to about 60,000 years old. It is used in dating things such as bone, cloth, wood and plant fibers that were created in the relatively recent past by human activities.

This Carbon 14 combines with oxygen to form carbon dioxide, which plants take in during photosynthesis

Animals and People eat the plants and take in the C14. We have a set amount of C12 in us, but the amount of C14 changes while we live.

Once we die, the amount of C14 decreases (by half in 5,700 years!!) but the amount of C12 in us stays constant (It is a STABLE isotope). So the RATIO C14 to C12 changes

C14 can be used to date any fossil up to about 60,000 years old…why the limit?

Driving Force of Evolution: Competition Limiting factors – any condition of the environment that limits the size of a population Limiting factors – any condition of the environment that limits the size of a population Carrying capacity – The number of organisms that can be supported by a particular ecosystem Carrying capacity – The number of organisms that can be supported by a particular ecosystem Overpopulation - the condition of having a population so dense as to cause environmental deterioration, an impaired quality of life, or a population crash Overpopulation - the condition of having a population so dense as to cause environmental deterioration, an impaired quality of life, or a population crash

Opening of ‘adaptive zones’ – allowed for new species to develop 3. Mass Extinction

4. Earth’s Geologic History 4. Earth’s Geologic History

6 th Mass Extinction Mass Extinction Event – YouTube 9.19 Mass Extinction Event – YouTube 9.19 Mass Extinction Event – YouTube Mass Extinction Event – YouTube Permian Mass Extinction5.06 Permian Mass Extinction5.06 Permian Mass Extinction Permian Mass Extinction Permian Methane Explosion 5.56 Permian Methane Explosion 5.56 Permian Methane Explosion Permian Methane Explosion