Evolution of Man
Evolution
Definition of Evolution the process by which species arise and
change over time. The idea that all organisms have
descended from common ancestors
Evolution
Charles Darwin Origin of Species, 1859 Decent with Modification Natural Selection Sexual selection
Evidence of Evolution
Fossil Record tells the story of evolution
Taxonomy Classifying organisms into groups
Comparative Anatomy Homologous structures Intermediate forms Vestigial structures
Comparative Embryology Early embryos of vertebrates are alike
Molecular Biology – DNA, proteins mtDNA
Fossils
An organism becomes a fossil only if it dies under the right conditions.
Majority of dead plants and animals are consumed by other organisms and leave no trace.
Dead organisms only leave a trace or imprint if they are quickly buried in a bog or at the bottom of a lake/ocean.
Clues of Human Evolution
Paleontologists find fossils
Clues of Human Evolution Remains of humans
were preserved in fossils
Bog is a wetland low in nutrients, slightly acidic soil .
Mossy Tollund Man. (Denmark) Europe Iron age 2,400
ya
Buried in mud or at the bottom of a body of water, the remains of the dead are protected from scavengers, erosion and decay.
Become buried deeply in successive layers of mud
Over time pressure from all these layers of sediment turns the deepest layers into sedimentary rock
After millions of years geologic forces raise the rock into mountains, canyons and reveal fossils
Sedimentary Rock
Grand Canyon showing layers of rock.
Taxonomy
All organisms are grouped into hierarchies based on their relationships.
Organisms of the same species can breed and produce viable offspring
Major taxonomic levels - KPCOFGS
Taxonomy
Common Name:
Human Chimpanzee Lion
Kingdom Animalia Animalia Animalia
Phylum Chordata Chordata Chordata
Class Mammalia Mammalia Mammalia
Order Primates Primates Carnivora
Family Hominidae Hominidae Felidae
Genus Homo Pan Panthera
Species sapiens troglodytes leo
Taxon0my
Binomial nomenclature Genus and species Homo sapiens. Homo means “self”
or “same”, meaning “the same as me” — which, for you, means “human”. Sapiens means “wise”. Homo sapiens means “Wise human”.
Comparative Anatomy
Species descended from a common ancestor may evolve in different directions and still keep some of the same characteristics
Evolutionary scientists compare the body structures of organisms to find clues.
Comparative Anatomy
Homologous Structures – similar structures in two or more species that give evidence of a common ancestor. Similar structure Same origin Different in function
Comparative Anatomy
Compare legs of Human and Ape
Comparative Anatomy
Intermediate forms – successive changes in homologous bone structures provide evidence of evolution.
Also called transitional forms
https://handfacts.wordpress.com/tag/evolution/
Comparative Anatomy
Comparing pelvis bones
Comparative Anatomy
Vestigial Structures A part of an
organism with little or no function that reflects evolutionary history
Comparative Embryology
Compare Embryo Development
Molecular Biology
DNA, mtDNA, proteins 20 -20,000 genes in the Human
Genome Molecular geneticists have compared
DNA sequences of Humans and chimpanzees
98.8% identical Humans are more closely related to
African apes than Asian apes (Immunological protein analysis)
Molecular Biology
DNA sequence comparisons
Mitochondrial DNA contains 37 genes Thirteen of these genes provide instructions
for making enzymes involved in oxidative phosphorylation. Oxidative phosphorylation is a process that uses oxygen and simple sugars to create adenosine triphosphate (ATP), the cell's main energy source.
The remaining genes provide instructions for making molecules called transfer RNA (tRNA) and ribosomal RNA (rRNA)
Mitochondrial DNA Passed from
mother to all her children
Points of mutations are a clear .
Molecular Biology
Observations
Primatologists observe our closest living relatives, apes and chimpanzees
Becoming Human
Sahelanthropus tchadensis Discovered in the Sahara Desert in 2001 Between 6 – 7 million years old Considered oldest known hominid fossil
Becoming Human
Homework
Look up Rift Valley Explain where it is Explain why it is important to the
study of Human Evolution.
Becoming Human
As we have evolved Humans have Larger brains Walk bipedally Sparse body hair Nonopposable toes and longer feet Grasping flexible thumb Unspecialized teeth Arching backs
Becoming Human
Australopithucus afarensis
Lucy Found in Ethiopia in 1974 This the earliest species
of Australopithecus, l ived in about 4 million
and 3 million years ago. brain was about the
same size as chimps 3 feet, 70 lbs
Becoming Human
The researchers also found that the model of locomotion produced in their simulations closely matched a set of fossilized footprints thought to have been left by A. afarensis in Laetoli, Tanzania, some 3.6 million years ago.
Becoming Human
They constructed the computer model using a fossilised A. afarensis skeleton known as "Lucy", recovered from Ethiopia in 1974. The researchers then added virtual muscle to their simulation and used genetic algorithms to "evolve" the optimal walking movement for the creature.
Becoming Human
Australopithicus africanus lived perhaps from 3
million to 1 million years ago, and probably evolved from A. afarensis
had a rounder skull and slightly larger brain
Tooth and jaw design suggest he chewed plant foods, but might also have scavenged meat from the remains of carnivores' kills.
Becoming Human
Neanderthal Man Fossils found in Germany
Becoming Human
Homo neanderthalensis More Neandertal skeletons
have been found than any other ancient human species.
They lived in Europe and Southwest Asia from at least 130,000 -28,000 years ago.
May have evolved from Homo heidelbergensis in Southern Europe.
Becoming Human
protruding jaw, receding forehead, and
weak chin. The average Neanderthal
brain was slightly larger than that of modern humans, but this is probably correlated with larger body size in general.
May have been a different species than Homo sapiens.
Homo heidelbergensis (600,000 to 100,000 years ago)
The skulls of this species share features with modern Homo sapiens.
brain was smaller than most modern humans
Becoming Human
Homo sapiens sapiens Cro magnum man Earliest modern man Lived 35,000 ya The body heavy and
solid , muscular. Straight forehead with
slight browridges Cro-Magnons were the
first humans to have a prominent chin.
Neanderthal vs Cro-magnun
Comparison of erectus, aferensis, neanderthal
An evolutionary comparison (from left to right: Homo erectus, 1 million years old; Australopithecus afarensis, 2.5 million years old; Homo neanderthalensis, 100,000 – 32,000 years old)