Remember: Two Ways to Look At Evolution MicroevolutionMacroevolution The formation of new species or taxonomic groups How did animals evolve, how did mammals evolve etc. We just finished this Moving on to this!

Macroevolution Big Changes

Can Selection Alone Cause Big Changes? Clearly

Macroevolution Is concerned with how new taxonomic groups or species came to be E.g. how did mammals evolve from ancestral reptiles (taxonomic group)

The Taxonomic Groups is how we organize all the organisms on the Earth! Domain Kingdom Phylum Class Order Family Genus Species **Do not need to memorize this for quizzes!***

Pneumonic Device Dude – Kings Play – Chess » On Fancy Gold Sets

Ex: Cat Taxonomy Domain – Kingdom Phylum – Class » Order Family Genus species Eukarya – Animalia Chordata (vertebrates) – Mammalia » Carnivora Felidae Felis catus

Example Felis Catus Felis

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 (also called Felis domesticus, 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

Different Species… Cannot have fertile, viable offspring**

**A Quick Note Identifying species (and other taxonomic levels) is trying to put all of nature into neat little boxes Nature don’t work like that..

Appearance can be misleading in determining a species. What is a species?

Members of Different Species May Be Similar in Appearance Fig. 16-1

Members of SAME Species May Differ in Appearance

Speciation is the process by which new species form 1. Populations Isolated May be physically (allopatric) or within an area (sympatric) 2. Populations genetically diverge

Part of a mainland population reaches to an isolated island Divergence may eventually become sufficient to cause reproductive isolation The isolated populations begin to diverge due to genetic drift and natural selection Allopatric Isolation and Divergence Fig. 16-9

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 Sympatric Isolation and Divergence Fig

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

Lizard evolution Ubc

Micro + Macro  The Big Picture Darwin’s Theory of Natural Selection

But How Could This

Evolve from this?

Very Gradually Over 4 Billion Years C3GA

But like, what’s a billion? 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

To Understand the Evolutionary Timescale Get 92cm worth of receipt 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

Step 2 Pick 10 MAJOR events in the history of the Earth (and life) – Do not focus on human events 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 Today2 ya6ya10ya 20ya4 ya 8ya 12 ya16ya 14 ya 18ya MJ 6-peats You all are born Y2k is a bust 9/11 Iraq War Obama Elected Burj Khalifa New Jones Built

Reproductive Barriers Pre-Zygotic No successful union of sperm and egg Post-Zygotic Zygote forms, but the resulting offspring is not fertile and viable