BIOLOGY I EVOLUTION Unit 3 Biological Evolution Evidence

BIOLOGY I EVOLUTION Unit 3 – Biological Evolution

Evidence for Evolution – Age of Earth James Hutton � 1788 Calculated Earth’s age to be millions of years old Charles Lyell � 1830 Rediscovered and reinforced Hutton’s ideas; provided more geological evidence Radiometric Dating of Age of Earth � Several different sources (Pb from U, Ar from K 40, mass and luminosity of our sun) � Earth 4. 54 billion years old ± 0. 05 billion years

Evidence for Evolution – Age of Earth If Earth is old, then there’s “plenty of time for evolution by natural selection to take place, ” (p. 466) If Earth changes, then why can’t the organisms on it change?

Evidence for Evolution - Fossils Robert Hooke � 1665 Proved that fossils are organisms’ remains � Revealed variation in the fossil record Georges Cuvier � 1796 Extensively studied fossils � Revealed variation in the fossil record Thomas Malthus � 1798 Founder of demography � Theorized that population size was limited by food supply

Darwin Born 1809 1831 HMS Beagle’s 5 yr. Voyage 1859 Published On the Origin of Species Died 1882

Darwin’s Voyage

Darwin’s Observations – Species Vary Globally Rheas: � Ground-dwelling � Live in Europe but NOT in South America nor Australia birds that only live in South America Ostriches: � Ground-dwelling birds that only live in Africa Emus: � Australian grounddwelling flightless bird Rabbits: Kangaroos: � Live in Australia but NOT Europe

Darwin’s Observations – Species Vary Locally Different, yet related, animal species can occupy different habitats within an area Darwin’s finches (next slide) Island Tortoises (p. 452)

Darwin’s Finches

Darwin’s Observations – Species Vary Over Time Picture comes from NASA Science News article � Mosses and ferns 425 mya � Flowering plants move from 130 mya to between 245 and 290 mya, according to Stanford geochemists

Evolution Summary Earth is approx. 4. 5 billion years old The Earth itself has changed over time Fossils indicate some (actually most) species are extinct Darwin, a naturalist, goes on voyage 1831, observes: � Species vary globally � Species vary locally � Species vary over time

Evidence for Evolution – Anatomy and Development Homologous Structures – body parts that share a common structure

Evidence for Evolution – Anatomy and Development Analogous Structures – body parts that share common function but NOT structure

Evidence for Evolution – Anatomy and Development Vestigial Structures – body parts that have lost much or all of their original function Examples: � Appendix � Wisdom � Coccyx teeth

Evidence for Evolution – Anatomy and Development

Evidence for Evolution – Anatomy and Development

Evidence for Evolution Summary Anatomy and Development � Homologous structures � Analogous structures � Vestigial structures � Embryological similarities between different species

Evolution by Natural Selection Variation exists within populations Some within a population are better suited for survival Over time, those that are better suited for survival spread their genetic information Fossil evidence (next slide)

Whale Evolution

Cladogram – to show similarities

Cladogram

And one more cladogram