Monday 2/8/2016 Agenda: Evolution Part II  Activity: Darwin’s Natural Selection Worksheet  Notes: Rate of Evolution Homework/Class Work: No Homework Tonight….unless…….

Darwin’s Natural Selection Worksheet Start: Q3 WK4 D4&5

Different kinds of organisms evolve at different rates Bacteria evolve much faster than complex cells The rate of evolution also differs within the same group of species In punctuated equilibrium, evolution occurs in spurts In gradualism, evolution occurs in a gradual, uniform way The Rate of Evolution Q3 WK4 D4&5

Punctuated equilibrium Gradualism

GRADULISMPUNCTUATED EQUILIBRIUM

Evidence of Evolution 1. Fossil Records 2. Molecular Records (Carbon Dating and DNA) 3. Anatomical Records

Fossils are the preserved remains, tracks, or traces of once-living organisms Fossils form when organisms become buried in sediment and calcium in hard surfaces mineralizes Arranging fossils according to age often provides evidence of successive evolutionary change Robert Hooke in st to propose that fossils are the remains of plants & animals. Provides the most direct evidence for macroevolution Fossil Records

Missing Links Lucy (Australopithecus afarensis) : 40 % complete skeleton. Lived 3.2 million years ago Ardi (Ardipithecus ramidus) : stood about 47 inches tall and weighed about 110 pounds. Took 15 years to unearth. Lived 4.4 million years ago

Fig Whale “missing links” Fossils have been found linking all the major groups The forms linking mammals to reptiles are particularly well known

More Missing Links Archaeopteryx. The most primitive known bird. Lived ~150 million years ago. Ambulocetus: The walking whale. This animal could walk as well as swim. It lived ~50 million years ago.

Tuesday 2/10/2016 Agenda: Evolution Part II  Notes: Fossil Records  Activity: Radioactive Dating Worksheet Homework/Class Work: Radioactive Dating Practice Worksheet due Wednesday/Thursday 2/10-2/11/2016

Fossil Records Relative Dating (aka Law of Superposition) by Nicolaus Steno By looking at where the fossils are in relation to the rock depth or layers, scientists can see when an organism goes extinct or when there is a mass extinction In other words, in a cross section of the Earth or rock layers, the lowest layer is the oldest

Molecular Records Certain atoms are known to decay (break down) at a specific rate. Scientists can look at these atoms to determine how old an organic object is. Radioactive isotope 14 C- gradually decays over time back to 14 N (known as Carbon Dating) It takes 5600 years for half of the 14 C present in a sample to be converted to 14 N. This length of time is called the half-life. Half life (t 1/2 ): the time needed for half of the atoms of the isotope to decay For fossils older than 50,000 yrs scientists use potassium isotope t 1/2 of 40 K = 1.3 billion years to turn to argon ( 40 Ar)

How do we use the method? Uranium-235 has a half-life of 700 million years. How much of the 12 g sample of Uranium-235 will be left after: a. 700 million years _______ b million years _______

Radioactive Dating Practice worksheet Lets practice radioactive dating Attach into your sci. ntbk

Wednesday/Thursday 2/10-2/11/2016 Agenda: Evolution II  Review: Radioactive Dating Worksheet  Activity: Dating the Iceman Worksheet  Activity: Iceman Murder Mystery Homework/Class Work:  Finish Radioactive decay worksheet due Friday 2/12/2016

Radioactive Dating Practice Lets practice radioactive dating to better understand the homework: How much of 20.0 grams of a substance will be left after 1 hour if the half life is 15 minutes (answer in grams) The half life of thorium-27 is days. How many days are required for 2.63 to remain if you start with grams?

Notebook Check Notes: Rate of Evolution Activities: Natural Selection of Cacti, Blood Donor Mix Up Questions, Darwin’s Natural Selection worksheet, Adaptations of Rabbits Foldable

Friday 2/12/2016 Agenda: Evolution Part II  Notes: Anatomical Records  Activity: Anatomical Records Foldable Homework/Class Work: Radioactive Dating Practice Worksheet due Wednesday/Thursday 2/10-2/11/2016

Similar structural forms can be seen in different living organisms 1. Homologous structures 2. Analogous structures 3. Vestigial structures All vertebrates share a basic set of developmental instructions Anatomical Record Relict developmental forms

Homologous structures: have same structure, DIFFERENT function. However, the structures are derived from the same part of a common ancestor Fig Homology among vertebrate limbs The same basic bones are present in each forelimb

Analogous structures: resemble each other as a result of needed adaptations to similar environments (Different animals adapt in similar fashion when challenged by similar opportunities) The feature has the same function but looks different.

Vestigial structures: Although the structure(s) had a purpose & function in the past but they are largely or entirely functionless now. a vestigial structure may retain lesser functions or develop new ones. The blind mole rat has tiny eyes completely covered by a layer of skin.blind mole rat The blue whale has tiny hind leg bones under its tail.