THEORY OF EVOLUTION Chapter 16

Idea of Evolution ◦Charles Darwin ( ) ◦English ________________ ◦Took a trip around the world on a ship called ________________ Mostly fascinated with the ________________ Islands ◦Best known for his theory of ________________ by natural selection

Darwin’s Journey ◦Began in ________________ ◦Sailed on a ship called the H.M.S. Beagle ◦Five year voyage sailing around the coast of ________________ ________________ and ________________

Observations Aboard the Beagle ◦Darwin collected 68 species of ________________ ◦Wrote about the different characteristics of habitats and species that live there ◦Species vary ________________ ◦There are similar organisms around that world with similar ecological ________________ ◦Ex: Rhea birds in S. America and ________________ in Africa

Observation Aboard the Beagle ◦Species vary ________________ ◦Related animals species often occupy different habitats within a ________________ area ◦Ex: Tortoise ________________ ________________ among Galapagos Islands

Observation Aboard the Beagle ◦Species vary ________________ ________________ ◦Some fossils of ________________ animals were similar to living species ◦Ex: Armadillo ________________ compared to modern day armadillos

Darwin’s Findings ◦Galapagos Islands ◦Groups of animals ________________ from island to island ◦Ex: tortoises on each island resemble each other but differ in the shape and function of their ________________ ◦Ex: finches on each island resembled each other but differ in the shape and function of their ________________ ◦Darwin believed these unique animals all came from a ________________ ________________ and they changed/adapted to their environment

Idea of Evolution ◦Evolution ◦Development of new types of organisms ________________ ________________ ◦Heritable ________________ in the characteristics within a population from one generation to the next

Ideas of Darwin’s Time ◦Scientists thought all species were ________________ and unchanging ◦The Earth was believed to only be a few ________________ (not billions) of years old ◦During Darwin’s time, new research was being done to figure out the ________________ of the Earth

Ideas that Influenced Darwin ◦James Hutton was a geologist in 1700’s ◦Made connections between mountains, valleys, and layers of ________________ ◦Believed the ________________ was older than thousands of years -- a time so old for the human mind to image ◦The Earth changes very ________________ and some layers can accumulate as the environment is changing

Ideas that Influenced Darwin ◦Charles Lyell was a English ________________ that believed the Earth’s surface continues to change ◦He explained that past processes that occurred are still occurring now ◦Ex: ________________ erupted in the past and still today ◦Published a great work called ________________ ______ ________________ in 1830 that built on the work of Hutton ◦Darwin read this book while on his journey around the world

Ideas that Influenced Darwin ◦Jean-Baptiste Lamarck ◦French naturalist that ________________ the idea that populations of organisms change over time

Ideas that Influenced Darwin ◦Proposed two hypotheses: Called Theory of ________________ ________________ ◦Organisms could ________________ during their lifetime by using or not using selected parts of the body ◦Individuals could pass these ________________ traits on to their offspring ◦Ex: Giraffes could ________________ their neck by stretching over a period of time to get the height they needed to eat and survive and then pass the longer neck trait to their ________________

Ideas that Influenced Darwin ◦Thomas Malthus was an English economist in the 1790s ◦Reasoned that if the human population grew continuously, there would not be enough ________________ for everyone ◦His reasoning explained why plants and animals produced more a high amount of ________________ since a portion will not ________________ due to environmental factors ◦Ex: Maple tree produces ________________ of seeds each summer ◦Ex: Oysters produce ________________ of eggs each year with the understanding that only a fraction will survive

Darwin’s Ideas ◦Around the same time Darwin and Wallace formed ________________ to explain evolution ◦Darwin was able to publish his book first called _______ _______ _____________ ______ ____________ in 1858 ◦Book explained how evolution occurs by means of ________________ ________________

Artificial Selection ◦Darwin studied ________________ breeders ◦Farmers would select to breed only _____________ with the largest fruit, or the _____________ that produce the most milk ◦Darwin called this process ________________ ________________ ◦Nature provides the ________________, and humans select hose they find to be useful and allow them to breed and pass on ________________ to offspring

Evolution by Natural Selection ◦Mechanism from descent with _____________ ◦1. Struggle for Existence ◦Organisms produce more offspring than can _____________ ◦Ex: grasshoppers lay over 200 _____________ at a time, but only a fraction survive ◦2. Variation and Adaptation ◦Traits vary within a species and their environment called _____________ ◦These adaptations help increase _____________ to survive ◦Ex: _____________ with coral snake and scarlet snake

Natural Selection (cont’d) ◦3. Survival of the Fittest ◦Organisms best _____________ for an environment will survive best and _____________ ◦The ability for an organism to _____________ and pass on adaptations ◦4. Natural Selection ◦Process by which organisms with _____________ most suited to their local environment survive and leave more _____________ ◦Organisms _____________ their mate based on desired traits

Common Descent ◦Idea that every species must have ___________ by reproduction from pre-existing ___________ that arrange over time ◦Ex: finch ___________ at Galapagos ◦All species – living and extinct – are descended from ancient _____________ ancestors

Transitional Species ◦Organisms with features that are _____________ hypothesized ancestors

Age of the Earth & Fossils ◦Noted that fossils of extinct animals _____________ living species ◦Relative Age ◦Age _____________ to other fossils in order of old to young ◦Absolute Age ◦Using radioactive dating to get _____________ _____________ age

Age of the Earth and Fossils ◦Age of the Earth ◦Geologists are certain based on evidence via radioactive dating to indicate the Earth is about _______ _____________ years old ◦Fossils ◦_____________ of an organism that died long ago ◦Many fossils form a series that can trace back to an ancient extinct _____________ ◦Superposition ◦Idea that _____________ form in layers where the layers closest to the _______ are the younger than below

Biogeography ◦Study of where organisms live _____________ and where they and their ancestors lived in the _____________ ◦Darwin used this method when exploring islands and observed _____________ vary based on their _____________ ◦Closely related but Different ◦Darwin believed that the finches of the _____________ all came from a common ancestor in the _____________ ◦Over time, _____________ selection produced a variation of species of finches ◦Distantly Related but Similar ◦Darwin noted that organisms that are _____________ related and inhabit similar environments have _____________ qualities

Anatomy and Embryology ◦Anatomy: study of the __________ ◦Embryology: study of _____________ ◦Homologous structures ◦Anatomical structures that originated from the _____________ common _____________ ◦Ex: bones in arms of humans, penguins, alligator and bat ◦Related _____________ but _____________ may differ

Anatomy and Embryology ◦Analogous Structures ◦When structures have similar _____________, but did not develop the same way ◦Ex: wings of bat vs. bird ◦Vestigial Structures ◦Organs that no longer serve a _____________ in an organism ◦Ex: human tail bone, appendix

Anatomy and Embryology ◦Embryology ◦Similar patterns of embryological _____________ provide further evidence that organisms have descended from a _____________ ancestor ◦Many animals look _____________ during development and produce _____________ tissue

Genetics and Molecular Biology ◦At the molecular level, the _____________ _____________ and homologous molecules provide _____________ of common descent

Phylogeny ◦_____________ among groups of organisms ◦Can make a “__________” of animals evolved ◦Trunk of the tree would represent species that are _____________ related ◦Branches represent a _____________ population or lineage

Caribbean Anole Lizard ◦Found in the Caribbean islands of Cuba, Hispaniola, Jamaica, and Puerto Rico ◦Each lizard species body type differs by their habitat ◦Ex: stocky body and long legged lizards are best adapted for tree truck environments, slender bodies and long tails are best adapted for grassy environments ◦Hypothesis #1: An ancestral anole species specialized for living on twigs originally lived on one island and later migrated to other islands OR ◦Hypothesis #2: Each twig-dwelling species evolved independently on each island from distant ancestor anole species

Evolution in Action ◦Biologists tested the hypothesis by comparing _____________ from the various species ◦DNA evidence supported hypothesis 2 that each lizard evolved _____________ on each island ◦Convergent Evolution ◦Process by which _____________ species evolve _____________ traits ◦Ex: twig-dwelling species came from different ancestors but evolved similar adaptations to their environment

Divergence & Radiation ◦Divergence evolution ◦Process by which the descendants of a _____________ ancestor diversify into species that each fit _____________ parts of the environment ◦Ex: All breeds of dog share a common ancestor with wolves

Divergence & Radiation ◦Adaptive Radiation ◦Pattern of diversity when a new population in a new _____________ undergoes divergent evolution

Coevolution ◦Evolution is on-going and many species may evolve _____________ ◦Coevolution ◦When _____________ or more species have evolved adaptations to each other’s _____________ ◦Ex: ◦Predator/Prey Interactions ◦Introduction of new species ◦Creating antibiotics