5/18/2015 Hello! Please remember to ask to leave the room Have your review HW out to be checked in. While I check it in you should discuss any 7.1 review questions with your table 7.1 exit slip Start 7.2 Activity: Time and Speciation HW: Finish your timeline! SP 0.4! Reassessment is THURSDAY. Please sign up in the front of the room on the clipboard. You can come any time, ends at 3:05. Elite? See me at end of class!

Where are we? Ppt review of 7.2-L1 Take notes Posted after the B day Pull out your Unit 7 Rubric. 1st assessment for 7.1 Starting 7.2 Today! 7.2 - Students understand how macroevolution explains the diversity of life on the planet Chapter 16 p.303-316 VOCAB Speciation Geologic time scale Biodiversity Extinction Phylogenetic tree Macroevolution L1 Explain the mechanism of speciation L2 Explain barriers of reproduction between two species L3 Analyze phylogenetic trees of evolutionary history Ppt review of 7.2-L1 Take notes Posted after the B day

Two Ways We Look At Evolution We just finished this ☺ Moving on to this! Microevolution Macroevolution Changes in a gene pool of a population E.g. a population accumulating; darker fur genes or “higher fitness number” genes The formation of new species or taxonomic groups! Includes: How did animals evolve? How did mammals evolve? Etc!

Macroevolution Big Changes

Can Selection Alone Cause Big Changes? YES!

Macroevolution Is concerned with how new taxonomic groups or species came to be Ex: How did mammals evolve from ancestral reptiles??? so…taxonomic groups!

The Taxonomic Groups is how we organize all the organisms on the Earth! Domain Kingdom Phylum Class Order Family Genus Species No need to memorize these – we will focus on Species. But I think it’s useful to understand what the goal is. Interestingly this all existed BEFORE the concept of evolution. Evolution convenient explains these observations- which is what a theory is! But this system will probably disappear within our lifetime because it really is arbitrary little boxes that don’t match how evolution functions.

JIC: Pneumonic Device – YOU DO NOT NEED TO MEMORIZE FOR QUIZZES  Dude Kings Play Chess On Fancy Gold Sets May help them in Trivia Crack?

Ex: Cat Taxonomy Eukarya Domain Animalia Kingdom Chordata (vertebrates) Mammalia Carnivora Felidae Felis catus Domain Kingdom Phylum Class Order Family Genus species We see evidence of relationships between all animals, vertebrates, mammals, carnivores, felines etc.

Felis Catus Felis Zoom in on Order Carnivora! Example

Scientific Names are based on Taxonomy Genus species of taxonomy put together and put in italics. Ex: humans are Homo sapiens/H. sapiens Ex: Domestic cat is Felis catus aka: Felis domesticus or Felis silvestrus

Modern Goal of Taxonomy Identify which species are most closely related to which E.g. which fossils we find represent ancestors, which represents cousins?

Speculative, but not a leap of Faith 7.3 – the Evidence!

Microevolution→ Macroevolution

So tell me…. What defines a species??? Whiteboard

*Note* Species (and other taxonomic levels) organizes nature into neat little boxes. Nature don’t work like that…our brains do! So… Lots of exceptions to the rule, e.g. hybrids, dogs/wolves etc. Difficult to classify asexual species Very difficult to classify extinct species

Different Species… Cannot naturally combine gene pools Cannot have fertile, viable offspring** Picture by Mrs. Sweis

Appearance can be misleading in determining a species.

Same species or different species? Members of Different Species May Be Similar in Appearance

Members of SAME Species May Differ in Appearance Same species or different species? Members of SAME Species May Differ in Appearance

Speciation is the process by which new species form 1. Populations Isolated 2. Populations genetically diverge No gene flow between them May be physically (allopatric) or within an area (sympatric) Populations adapt differently and accumulate genetic differences Eventually they are too different to reproduce

Allopatric Isolation and Divergence Part of a mainland population reaches to an isolated island The isolated populations begin to diverge due to genetic drift and natural selection Divergence may eventually become sufficient to cause reproductive isolation

Sympatric Isolation and Divergence Part of a fly population that lives only on hawthorn trees moves to an apple tree The flies living on the apple tree do not encounter the flies living on the hawthorn tree, so the populations diverge Fig. 16-10

Is this Plausible? Yes! There is observed experimental evidence of speciation.

Micro + Macro → The Big Picture! -Darwin’s BIG IDEA -natural selection takes place in populations that are isolated -over LONG periods of time, small changes in allele frequencies from gen to gen can add up to BIG changes in species. -This leads us again to the idea of a universal common ancestor.

But How Could This

Evolve from this?

Very Gradually Over 4 Billion Years https://www.youtube.com/watch?v=hsHwCc9C3GA  

How Much is a Billion? (compared to a million) 1 million seconds = about 12 days 1 billion seconds = about 32 years 1 million minutes ago was approximately 2 years ago 1 billion minutes ago was the year 114AD 1 million hours ago it was the dawn of the 20th century (1901) 1 billion hours ago was around the time we think the first modern humans walked (141k ya) 1 million days ago it was about 700BC 1 billion days ago was 2.7 million years BC The magnitude of difference between billion and million can be illustrated with this example of the time scale: A million seconds is 12 days. A billion seconds is 31 years. A trillion seconds is 31,688 years.

To Understand the Evolutionary Timescale Each person gets 92cm worth of paper Scale out 4.6 billion years on that paper (the approximate age of the Earth) The 4.6 billion years should use up all 92 cm. Why are we asking you to use 92 cm HINT HINT… Check with your teacher to see if your scale is appropriate

NEXT… Pick 10 MAJOR events in the history of the Earth (and life) Do not focus on human events! You have 4.6 billion years to look at! Get this list approved  Identify approximately when they occurred and place a sketch or small picture at the appropriate point. Label what happened

E.g. if you did the last 20 years MJ 6-peats You all are born 9/11 Obama Elected Burj Khalifa Y2k is a bust Iraq War New Jones Built 20ya 18ya 16ya 14 ya 12 ya 10ya 8ya 6ya 4 ya 2 ya Today

HOMEWORK Finish your timeline and bring it to class SP 0.4, fill out your survey! ELITE: come see me now Optional HW: Come to Ac Lab and review your last Unit test Read the corresponding pages in the wolf book. Review this power point on the HHW

Reproductive Barriers Pre-Zygotic Post-Zygotic No successful union of sperm and egg Zygote forms, but the resulting offspring is not fertile and viable Probably pull this to a second day????? But is them L1? That’s something I was trying to determine from the rubric