7A Evidence of Evolution Fossil Evidence & Biogeography 7A analyze and evaluate how evidence of common ancestry among groups is provided by the fossil record, biogeography, and homologies, including anatomical, molecular, and developmental.
5 min In: How does fossil evidence gives us clues to how organisms from the past are related to organisms from today? Write your answer on the paper Discuss with partner Discuss as a class
You have 3 minutes!!!! 3 min Dating the Fossil Record You have received nine rock samples from a paleontologist in California. Your job is to arrange the samples in order from oldest to youngest according to their fossil content. Results from absolute dating methods will not be available from a laboratory for several weeks, and the paleontologist needs the information immediately. Begin with Sample 2. They are the oldest rocks.
2 min
2 min Dating the Fossil Record Discuss with your partner or group Describe what might have happened to some of the organisms from the beginning to now. Develop a hypothesis of how some of the species changed or became extinct over time? Do you have any evidence?
2 min Dating the Fossil Record Discuss with your partner or group 1. Which one of the species is the common ancestor? Which sample can we find it in? 2. Which one of the species is the modern species? Which sample can we find it in? 3. Does the modern species resemble the ancient common ancestor?
Evolution is a Theory Just like Gravity! Evolution - gradual change in the genetic makeup of a population through successive generations. Theory - a well tested explanation supported by evidence
Description Similarities of in the fossil record reflects that organisms have a common ancestor. in bone structure of specific species shows over time. Fossil record has revealed links between large groups of organisms such as from to and reptile to. change fish reptile species bird variations
complex gaps Fossil Record shows: Relative of a species How species found in the layers are very from what is in the top layer Species today are more (cell structure, DNA) That when new species, others become arise gradual evolution in species over time in the timeline and is not. age different complete bottom extinct
Evolution of the Horse
Biogeography
Biogeography Simulation See lesson plan for directions
In: Why are some species only found in some parts of the world and not others? Write your answer Discuss with partner Discuss as a class
Description: Biogeography the study of isolation and drift. continental geographical
Species a group of individuals that actually or potentially interbreed (sexually) in nature
Speciation event that produces two or more separate species Click here for the story
How does one species become two species? Reproductive isolation is the most common cause. For example, if some flies land on an island with no flies they may evolve into one or more new species that are different from the species where they originally came from.
Diversity Name some animals that inhabit the austin-round rock area. Aka: biodiversity the different varieties of organisms inhabiting a particular region
Geographical Isolation Describe what you think this might mean to your partner. Species are separated due to an event or natural barrier leads to speciation
(clockwise from top) a chameleon, an aye aye, a fossa, and a baobab. All are native to Madagascar. Why is Madagascar home to so many unique plants and animals? Biogeography
Madagascar then.
Madagascar then & now
Madagascar..now! Rarest species on earth found no where else
Speciation: From 1 specie to 5. 1. One simple specie 2. Island breaks away species A evolves into species B 3. Island breaks away again species B evolves into species C 4. Geographic isolation occurs because of mountain ranges species C is separated leading to a new species D 5. Island breaks away again species D evolves into species E.
1. Who is the ancestral species? 2. Is the ancestral species still alive today? How? 3. Are these species related to each other? 4. What s another way new species can show up in an isolated area? From 1 specie to 5.
The following mammals did not exist in Madagascar but instead they used natural rafts to get to the island. (At least in theory)
So if you had ticket, you had a ride Why don t lions, elephants, apes, antelopes, & zebras exist in Madagascar?
Any animal can move to another location as long as it can find a way.
Out: Describe how evidence of common ancestry is provided by biogeography. Use the terms: common ancestor, species, speciation, diversity, geographic isolation, continental drift.
Predict: From what you have learned about the fossil record and biogeography, predict what happened to the Hawaiian Islands and to the number of species over time.
Today 5 MYA 10 MYA 15 MYA Gibbon Orangutan Chimp Human Gorilla MYA= Millions of years ago Above image modified from http://www.learner.org/channel/courses/biology/textbook/humev/humev_3.ht ml Based on DNA evidence, scientists have constructed this phylogeny of primates. A B D C 1.At which node is the common ancestor of chimps and orangutans? Life Sciences-HHMI Outreach. Copyright 2006 President and Fellows of Harvard College. 2. To which primate are humans most closely related? How do you know? 3.At which node is the common ancestor of all primates? How many years ago did it exist? 4.Is it accurate to say that humans came from chimps? Explain.