Week 8 ~ Evolution of Chordates, History of Evolution, Natural Selection in Anoles

Plato and Aristole view

• animals are arranged from low to high complexity

Carolus Linnaeus

• God created plant and animals, NO evolution

Georges Cuvier

• fossils

• earth goes through sudden changes that lead to extinction

• new and better replace extinct

James Hutton and Charles Lyell

• gradual processes such as erosion and weathering

• inspired Darwin

Jean Baptist Lamarck

• will change if they need to

• evolve within their lifetime

Charles Darwin & Alfred Russel

• common ancestor

• gradual processes in biological diversity like geologic features from (hutton)

• natural selection

Ernest Mayr

• developed modern evolutionary synthesis

• combined natural selection with Mendelian inheritance

• refined natural selection, its apart of a lot of other reasons for why species are how they are

Main diff between Lamarck and Darwin/Wallace?

• Lamarck thought animals change in lifetime, grow longer neck etc

• but, its just the strongest survive and the ones who don’t have the desirable trait tend to not survive and have as much children (Charles Darwin)

What are the characteristics present in all chordates?

• a notochord: stuff muscle work against during swimming

• dorsal nerve chord: develops brain and spinal cord

• Pharyngeal slits: allow filter feeding, turned into gills

• endostyle: assists in filter-feeding, develops into thyroid (release hormones)

What are some benefits of important milestones in the evolution of different classes of chordates?

What are the important adaptations that allowed for life on land?

• hox genes: allows for more complex body plans, structures and functions

• movement became more efficient

• increased cephalization

• adaptation to cold

• nervous system and brain

What is the countercurrent heat exchange?

• blood warms up before going to the body

• cold blood stays in feet and doesn’t cause frost damage

What is ectothermy vs endothermy?

• ecto= relying on outside sources such as sun

• endo= own body heat retention by hair, scales, feather, etc

What are hox genes?

• allowed for complex body plans, structures and functions

How did the amniotic egg allow reptiles and mammals to spread to dry and cold climates?

What is the vertebral column?

• spine/backbone

• protects spinal/nerve cord

• efficiency movement

In which chordate did the ling evolve into a swim bladder?

• ray-finned fishes

What do lungs allow for?

• sufficient gas exchange especially on dry land

• helps with buoyancy in oxygen poor shallow water

What did the vertebral column become in jawed vertebrates?

• larger and mineralized

• fully protected the nerve cord

What are the benefits of a jaw?

• allow organism to eat, chew, tear food

What is adaptation and how does it evolve?

• it is a beneficial trait that becomes common in a population because individuals with this trait have many offspring

Which genetic changes likely facilitate the major adapations in chordates?

• endothermic

• kidneys to conserve water and waste movement

• milk glands

• physical birth

• hair and blubber

What is the benefit of an amniotic egg?

• no larvae stage needed anymore

• protects against dehydration, shock absorb, gas exchange, transfer nutrients, storage of waste

What are epidermal structures?

• made of keratin

• gave rise to scales, hairs and feathers

How are epidermal structures beneficial?

• conserve water and body heat

• defend

• camoflauge

Explain important attributes of a hypothesis

• states a prediction and mechanism

• based on observations, theories and background info

• detailed yet simple

• deductive: specific using general theories

What is an independent vs dependent variable?

• independent is the one you change to test effect on the dependent variable

• dependent is what you measure (length, body weight, etc)

Outline a suitable experimental design given a certain hypothesis and situation

How does one interpret/draw conclusions from graphs?

Compare and contrast deductive and inductive reasoning

Explain why one may notice morphological and behavioral changes from one generation to the next when a population is exposed to selection pressure?

Predict whether natural selection is likely to occur in a population

Why is variation, selection pressure and heritability necessary for natural selection to occur?

What is the difference between micro and macro evolution?

How can selection shape a population?

What are examples of stabilizing selection?

What are examples of directional selection?

What are examples of diversifying selection?

What are examples of frequency-dependent selection?

What are examples of sexual selection?

What is non-random mating and why may it lead to evolution?

What is the difference between intra and inter sexual selection and what can one predict from each?