QMUL SBCS Human Evolution

2. Human evolution
Ancestors, relatives & major transitions
Recent insights from genomics
What about today?

3. Benton (2005)
Fig 10.47

4. Relatives and recent ancestors
“Higher primates” = Old world monkeys + Apes
25 MYA
simple chewing surfaces—a feeding ap-paratus
HOMINIDS
HOMINOIDS
FAMILY TREE of hominoids encompasses the lesser apes (siamangs and
gibbons), great apes (orangutans, gorillas and chimpanzees), and humans. Most
Miocene apes were evolutionary dead ends. But researchers have identifi ed a handful
of them as candidate ancestors of living apes and humans. Proconsul, a primitive
Miocene ape, is thought to have been the last common ancestor of the living hominoids;
Sivapithecus, an early great ape, is widely regarded as an orangutan forebear; and either
Dryopithecus or Ouranopithecus may have given rise to African apes and humans.
suspensory locomotion, especially in
Asia. Most phylogenetic analyses
CATARRHINI
HYLOBATIDS
CERCOPITHECOIDS
PLATYRRHINI
SPIDER MONKEY MACAQUE SIAMANG GIBBON ORANGUTAN GORILLA HUMAN CHIMPANZEE
PROCONSUL SIVAPITHECUS
OURANOPITHECUS
16 MYA
19 MYA
DRYOPITHECUS
40 MILLION YEARS AGO
14 MYA
9 MYA
6 MYA
Potential
common
ancestors
(Miocene)
New world
monkeys
Old world
monkeys Lesser
apes
Apes
Great Apes
© Scientific American

5. Proconsul
Some ape-like features
Some monkey-like
features

6. East African Rift Valley

7. Relatives and recent ancestors
© Scientific American
25 MYA
simple chewing surfaces—a feeding ap-paratus
well suited to a diet of soft, ripe
fruits. They also possessed shortened
HOMINIDS
HOMINOIDS
FAMILY TREE of hominoids encompasses the lesser apes (siamangs and
gibbons), great apes (orangutans, gorillas and chimpanzees), and humans. Most
Miocene apes were evolutionary dead ends. But researchers have identifi ed a handful
of them as candidate ancestors of living apes and humans. Proconsul, a primitive
Miocene ape, is thought to have been the last common ancestor of the living hominoids;
Sivapithecus, an early great ape, is widely regarded as an orangutan forebear; and either
Dryopithecus or Ouranopithecus may have given rise to African apes and humans.
suspensory locomotion, especially in
the elbow joint, which was fully extend-able
and stable throughout the full range
Asia. Most phylogenetic analyses
concur that it is from Si vapithecus that
the living orangutan, Pon go pygmaeus,
CATARRHINI
HYLOBATIDS
CERCOPITHECOIDS
PLATYRRHINI
SPIDER MONKEY MACAQUE SIAMANG GIBBON ORANGUTAN GORILLA HUMAN CHIMPANZEE
PROCONSUL SIVAPITHECUS
OURANOPITHECUS
16 MYA
19 MYA
DRYOPITHECUS
40 MILLION YEARS AGO
14 MYA
9 MYA
6 MYA
Potential
common
ancestors
(Miocene)

8. Major transitions in human
evolution
• Bipedalism (down from the trees)
• Increased brain size
In which order?

9. Homo!
Australopithecus africanus/!
A. afarensis!
Ardipithecus ramidus!
Orrorin tugenensis!
P. robustus!
Million!
years!
Glacial cycles!
Arctic icecap!
Antarctic icecap!
Climate!
Cold!Warm!
WP!
• Life in trees.
• Occasionally go down
• New context required going down more often?

10. Why bipedalism?
Mid Miocene! Late Miocene!
• Energy efficient locomotion (for
distant food sources)
• Less exposure to sun?
• Free the hands? (for gathering/
hunting?)
• Seeing farther: Finding food &
avoiding predators?
• Anti-predator displays?
• Cultural - escalated through
Sexual selection?
• Sexual displays?
Climate!
cooling!
Habitat!
fragmentation!
Homo!
Australopithecus africanus/!
A. afarensis!
Ardipithecus ramidus!
Orrorin tugenensis!
P. robustus!
Million!
years!
Glacial cycles!
Arctic icecap!
Antarctic icecap!
Climate!
Cold!Warm!

11. Running
• sweating for thermoregulation.
• arched foot + achilles tendon
• head stabilization
• early Homo?
• first: improved scavenging.
• then persistence hunting

12. Major transitions in human
evolution
• Bipedalism (down from the trees)
• Increased brain size
• Use of simple stone tools
• Fire, spears & other sophisticated tools (stone, bone...)
• Language, complex culture
• Agriculture...
In which order?

14. Relatives and recent ancestors
© Scientific American
25 MYA
simple chewing surfaces—a feeding ap-paratus
well suited to a diet of soft, ripe
fruits. They also possessed shortened
HOMINIDS
HOMINOIDS
FAMILY TREE of hominoids encompasses the lesser apes (siamangs and
gibbons), great apes (orangutans, gorillas and chimpanzees), and humans. Most
Miocene apes were evolutionary dead ends. But researchers have identifi ed a handful
of them as candidate ancestors of living apes and humans. Proconsul, a primitive
Miocene ape, is thought to have been the last common ancestor of the living hominoids;
Sivapithecus, an early great ape, is widely regarded as an orangutan forebear; and either
Dryopithecus or Ouranopithecus may have given rise to African apes and humans.
suspensory locomotion, especially in
the elbow joint, which was fully extend-able
and stable throughout the full range
Asia. Most phylogenetic analyses
concur that it is from Si vapithecus that
the living orangutan, Pon go pygmaeus,
CATARRHINI
HYLOBATIDS
CERCOPITHECOIDS
PLATYRRHINI
SPIDER MONKEY MACAQUE SIAMANG GIBBON ORANGUTAN GORILLA HUMAN CHIMPANZEE
PROCONSUL SIVAPITHECUS
OURANOPITHECUS
16 MYA
19 MYA
DRYOPITHECUS
40 MILLION YEARS AGO
14 MYA
9 MYA
6 MYA
Potential
common
ancestors
(Miocene)

15. Most lineages
went extinct
H. erectus
Proconsulidae
H. neanderthalensis
H. sapiens
Australopithecines

17. Australopithecines
Wikipedia

18. Taung child
Nature 1925
mya
Australopithecus afarensis 2.5 mya

19. Lucy - Australopithecus afarensis
1978 3.2 mya

20. Australopithecines
30° 20° 10° 0° 10° 20° 30° 40° 50° 60°
0 (km) 3 000
0 (mi) 2 000
Projection de Lambert azimutale équivalente
30°
20°
10°
0°
10°
20°
30°
P. Aethiopicus
30° 20° 10° 0° 10° 20° 30° 40° 50° 60°
30°
20°
10°
0°
10°
30°
A. Gahri
P. Boisei
A. Afarensis
A. Anamensis
A. Bahrelghazali
A. Africanus
P. Robustus (Crassidens)
Wikipedia
Brain size: 35% of
modern human
!

22. Evidence for bipedalism in Australopithecines

23. Evidence for bipedalism in Australopithecines

24. Evidence for bipedalism in Australopithecines
• Pelvis short & broad (like humans), not long & narrow (like gorilla)
• Hip & walking muscles arranged like in a bipedal organism
• Femur angled as in humans, not straight as in chimps
• Feet

25. Fossilized tracks at
Laetoli (Tanzania)
3.6Mya
Footprints preserved in
volcanic ash from: 3 hominids
(Australopithecus afarensis)
Numerous other mammals

26. Tool use?
• generally: only simple tools (similarly to current non-human
great apes).
• but Australopithecus garhi (2.5 mya) may have made stone
tools.

27. Summary: Australopithecines
• Major group of early bipedal hominids (4mya to 1 mya)
• Small brains
• Only in Africa
• Many forms/species

29. Most lineages
went extinct
Proconsulidae
Australopithecines
H. erectus
H. neanderthalensis
H. sapiens

30. Homo

31. Homo habilis

32. Tool use
Chimps and other animals
may use objects as tools.
H. sapiens! H. habilis! Australopithecine!
H. habilis made tools
Cutting Scraping

33. Stages of human
evolution are defined by
the style and
sophistication of stone
tools….
e.g.:
•Oldowan (2.5-1.5 mya)
•Achuelian (1.5-0.2 mya)

34. Oldowan tools
Hammerstone Choppers
Scraper Flakes

35. Homo habilis

36. Brain sizes increase

38. Out of Africa - H. erectus

39. Acheulian tools
Handaxe
Handaxes! Cleaver!
Pick!
Scraper! Trimming flakes!

40. Nariokotome/Turkana
boy
H. erectus
Found 1984 in Kenya. From1.5mya

41. H. erectus lifestyle
• Stone tools (Acheulian)
• Fire
• Sociality
• Hunting
• …language?

43. Homo floresiensis “The Hobbit”
H. florensis vs. H. sapiens skull
Nature (2004) vol. 431, 1043-1044

44. Nature (2004) vol. 431, 1043-1044

46. Neanderthal
600,000-30,000 years ago

47. Culture?

48. H. neanderthalensis
died out when H sapiens arrived

50. Neanderthals - Summary
• Neanderthals were morphologically and genetically distinct
from early H. sapiens
• disappeared after H. sapiens arrived - possibly because they
were culturally less advanced.

51. Most lineages
went extinct
Proconsulidae
Australopithecines
H. erectus
H. neanderthalensis
H. sapiens

52. H. sapiens out of Africa
• 50,000 years ago: fully “modern” with language, music, advanced
social intelligence, strategic planning etc.
• 70,000 years ago: began migrating out of Africa
• Simultaneous decline of other Homo species (erectus,
neanderthalensis...): competition?
• Superior cooperation & learning due to language?
• Agriculture ~ 10,000 years ago

54. Burial ritual in
early H. sapiens
• At Sungir, Russia, around 28,000
years ago
• A 60 year old buried with an
elaborate collection of beads,
necklaces and bracelets

55. Examples of early H. sapiens tools

56. Lascaux - 35000 years ago
Lion man, Ulm - 40,000 years ago
Flute - 36,000 years ago

58. Recent insights from genomics

59. A Draft Sequence of the
Neandertal Genome
Richard E. Green,1*†‡ Johannes Krause,1†§ Adrian W. Briggs,1†§ Tomislav Maricic,1†§
Udo Stenzel,1†§ Martin Kircher,1†§ Nick Patterson,2†§ Heng Li,2† Weiwei Zhai,3†||
Markus Hsi-Yang Fritz,4† Nancy F. Hansen,5† Eric Y. Durand,3† Anna-Sapfo Malaspinas,3†
Jeffrey D. Jensen,6† Tomas Marques-Bonet,7,13† Can Alkan,7† Kay Prüfer,1† Matthias Meyer,1†
Hernán A. Burbano,1† Jeffrey M. Good,1,8† Rigo Schultz,1 Ayinuer Aximu-Petri,1 Anne Butthof,1
Barbara Höber,1 Barbara Höffner,1 Madlen Siegemund,1 Antje Weihmann,1 Chad Nusbaum,2
Eric S. Lander,2 Carsten Russ,2 Nathaniel Novod,2 Jason Affourtit,9 Michael Egholm,9
Christine Verna,21 Pavao Rudan,10 Dejana Brajkovic,11 Željko Kucan,10 Ivan Gušic,10
Vladimir B. Doronichev,12 Liubov V. Golovanova,12 Carles Lalueza-Fox,13 Marco de la Rasilla,14
Javier Fortea,14¶ Antonio Rosas,15 Ralf W. Schmitz,16,17 Philip L. F. Johnson,18† Evan E. Eichler,7†
Daniel Falush,19† Ewan Birney,4† James C. Mullikin,5† Montgomery Slatkin,3† Rasmus Nielsen,3†
Janet Kelso,1† Michael Lachmann,1† David Reich,2,20*† Svante Pääbo1*†
Neandertals, the closest evolutionary relatives of present-day humans, lived in large parts of Europe
and western Asia before disappearing 30,000 years ago. We present a draft sequence of the Neandertal
genome composed of more than 4 billion nucleotides from three individuals. Comparisons of the
Neandertal genome to the genomes of five present-day humans from different parts of the world
identify a number of genomic regions that may have been affected by positive selection in ancestral
modern humans, including genes involved in metabolism and in cognitive and skeletal development.
We show that Neandertals shared more genetic variants with present-day humans in Eurasia than with
present-day humans in sub-Saharan Africa, suggesting that gene flow from Neandertals into the
ancestors of non-Africans occurred before the divergence of Eurasian groups from each other.
The morphological features typical of Nean-dertals
first appear in the European fossil
record about 400,000 years ago (1–3).
Progressively more distinctive Neandertal forms
subsequently evolved until Neandertals disap-peared
from the fossil record about 30,000 years
ago (4). During the later part of their history,
Neandertals lived in Europe and Western Asia
as far east as Southern Siberia (5) and as far
south as the Middle East. During that time, Nean-dertals
ancestors of present-day Europeans.
Similarly, analysis of DNA sequence data from
present-day humans has been interpreted as evi-dence
both for (12, 13) and against (14) a genetic
contribution by Neandertals to present-day hu-mans.
The only part of the genome that has been
examined from multiple Neandertals, the mito-chondrial
DNA (mtDNA) genome, consistently
falls outside the variation found in present-day
humans and thus provides no evidence for inter-breeding
parts of their genome with the ances-tors
of these groups.
Several features of DNA extracted from Late
Pleistocene remains make its study challenging.
The DNA is invariably degraded to a small aver-age
size of less than 200 base pairs (bp) (21, 22),
it is chemically modified (21, 23–26), and extracts
almost always contain only small amounts of en-dogenous
DNA but large amounts of DNA from
microbial organisms that colonized the specimens
after death. Over the past 20 years, methods for
ancientDNAretrieval have been developed (21, 22),
largely based on the polymerase chain reaction
(PCR) (27). In the case of the nuclear genome of
Neandertals, four short gene sequences have been
determined by PCR: fragments of the MC1R gene
involved in skin pigmentation (28), a segment of
the FOXP2 gene involved in speech and language
(29), parts of the ABO blood group locus (30), and
a taste receptor gene (31). However, although PCR
of ancient DNA can be multiplexed (32), it does
not allow the retrieval of a large proportion of the
genome of an organism.
The development of high-throughput DNA se-quencing
technologies (33, 34) allows large-scale,
genome-wide sequencing of random pieces of
DNA extracted from ancient specimens (35–37)
and has recently made it feasible to sequence ge-
RESEARCHARTICLE
1Department of Evolutionary Genetics, Max-Planck Institute for
Evolutionary Anthropology, D-04103 Leipzig, Germany. 2Broad
Institute of MIT and Harvard, Cambridge, MA 02142, USA.
3Department of Integrative Biology, University of California,
Berkeley, CA 94720, USA. 4European Molecular Biology
Laboratory–European Bioinformatics Institute, Wellcome Trust
Genome Campus, Hinxton, Cambridgeshire, CB10 1SD, UK.
5Genome Technology Branch, National Human Genome Re-search
Institute, National Institutes of Health, Bethesda, MD
20892, USA. 6Program in Bioinformatics and Integrative Biology,
University of Massachusetts Medical School, Worcester, MA
01655, USA. 7Howard Hughes Medical Institute, Department
of Genome Sciences, University of Washington, Seattle, WA
98195, USA. 8Division of Biological Sciences, University of
Downloaded from www.sciencemag.org on March 24, 2013
2-4% of eurasian DNA comes from Neanderthals

60. Strong reproductive isolation between humans
To examine these issues and clarify the process between Neanderthals and modern humans, we and spatially explicit model of admixture between modern humans and Neanderthals (3). simulations, we have estimated the interbreeding between humans and Neanderthals as well as the hybridization that is compatible with the observed Neanderthal ancestry in contemporary humans, latter migrated out of Africa into Eurasia 50 kya Results
Low Rates of Interbreeding Between Humans Using spatially explicit simulations, we have expected amount of Neanderthal ancestry in present-from Europe (France) and Asia (China) for admixture with Neanderthals and over various ranges (Fig. 1). Under our model of range expansion, we find that observed low levels introgression into Eurasians imply the existence strong barriers to gene flow between the two Strong reproductive isolation between humans
and Neanderthals inferred inferred from from observed
observed
patterns of introgression
introgression
Mathias Currata,1 and Laurent Excoffierb,c,1
aAnthropology, Genetics, and Peopling History Laboratory, Anthropology Unit, Department of Genetics and Evolution, University 1227 Mathias Currata,1 and Laurent Excoffierb,c,1
aAnthropology, Genetics, and Peopling History Laboratory, Anthropology Unit, Department of Genetics and Evolution, University of Geneva,
Geneva, Switzerland; bComputational and Molecular Population Genetics Laboratory, Institute of Ecology and Evolution, University 3012 Geneva, Switzerland; bComputational and Molecular Population Genetics Laboratory, Institute of Ecology and Evolution, University Berne, Berne, Switzerland; Switzerland; and and cSwiss cSwiss Institute Institute of of Bioinformatics, Bioinformatics, 1015 1015 Lausanne, Lausanne, Switzerland
Switzerland
by Svante Pääbo, Max Planck Institute of Evolutionary Anthropology, Leipzig, Germany, and approved August 3, 2011 (received 10, 2011)
Edited by Svante Pääbo, Max Planck Institute of Evolutionary Anthropology, Leipzig, Germany, and approved August 3, 2011 (received May 10, 2011)
Recent studies have revealed that 2–3% of the genome of non-
Africans might come from Neanderthals, suggesting amore complex
scenario of modern human evolution than previously anticipated. In
this paper, we use a model of admixture during a spatial expansion
to study the hybridization of Neanderthals with modern humans
during their spread out of Africa. We find that observed low levels
of Neanderthal ancestry in Eurasians are compatible with a very low
rate of interbreeding (<2%), potentially attributable to a very strong
avoidance of interspecific matings, a low fitness of hybrids, or both.
These results suggesting the presence of very effective barriers to
geneflowbetween the twospecies are robust to uncertainties about
the exact demography of the Paleolithic populations, and they are
also found to be compatible with the observed lack of mtDNA in-trogression.
studies have revealed that 2–3% of the genome of non-
might come from Neanderthals, suggesting amore complex
of modern human evolution than previously anticipated. In
paper, we use a model of admixture during a spatial expansion
the hybridization of Neanderthals with modern humans
during their spread out of Africa. We find that observed low levels
of Neanderthal ancestry in Eurasians are compatible with a very low
rate of interbreeding (<2%), potentially attributable to a very strong
avoidance of interspecific matings, a low fitness of hybrids, or both.
These results suggesting the presence of very effective barriers to
geneflowbetween the twospecies are robust to uncertainties about
the exact demography of the Paleolithic populations, and they are
also found to be compatible with the observed lack of mtDNA in-trogression.
Ourmodel additionally suggests that similarly lowlevels
Ourmodel additionally suggests that similarly lowlevels
of introgression in Europe and Asia may result from distinct admix-ture
of introgression in Europe and Asia may result from distinct admix-ture
events having occurred beyond the Middle East, after the split of
events having occurred beyond the Middle East, after the split of
Europeans and Asians. This hypothesis could be tested because it
predicts that different components of Neanderthal ancestry should
be present in Europeans and in Asians.
Europeans and Asians. This hypothesis could be tested because it
predicts that different components of Neanderthal ancestry should
be present in Europeans and in Asians.
To examine these issues and clarify the process between Neanderthals and modern humans, and spatially explicit model of admixture between modern humans and Neanderthals simulations, we have estimated the interbreeding between humans and Neanderthals as well as hybridization that is compatible with the observed Neanderthal ancestry in contemporary humans, latter migrated out of Africa into Eurasia 50 Results
Low Rates of Interbreeding Between Humans Using spatially explicit simulations, we expected amount of Neanderthal ancestry in from Europe (France) and Asia (China) for admixture with Neanderthals and over various ranges (Fig. 1). Under our model range expansion, we find that observed low levels introgression into Eurasians imply the existence

61. ARTICLE Nature 2010 doi:10.1038/nature09710
Genetic history of an archaic hominin
group from Denisova Cave in Siberia
David Reich1,2*, Richard E. Green3,4*, Martin Kircher3*, Johannes Krause3,5*, Nick Patterson2*, Eric Y. Durand6*, Bence Viola3,7*,
Adrian W. Briggs1,3, Udo Stenzel3, Philip L. F. Johnson8, Tomislav Maricic3, Jeffrey M. Good9, Tomas Marques-Bonet10,11,
Can Alkan10, Qiaomei Fu3,12, Swapan Mallick1,2, Heng Li2, Matthias Meyer3, Evan E. Eichler10, Mark Stoneking3,
Michael Richards7,13, Sahra Talamo7, Michael V. Shunkov14, Anatoli P. Derevianko14, Jean-Jacques Hublin7, Janet Kelso3,
Montgomery Slatkin6 & Svante Pa¨a¨bo3
• Only known remains(all found since 2010): phalanx (finger
bone), three teeth, a toe bone. From 41,000 years ago.
• Amazingly well preserved DNA (Siberia; average temperature
0°C). ⇒ sequenced the genome.
• Common ancestor with Neanderthal: 600,000 years ago
• Interbreeding with Homo sapiens: 4-6% of Melanesian
genomes are from Denisovan.
UsingDNAextracted froma finger bone found in Denisova Cave in southern Siberia,wehave sequenced the genome of an
archaic hominin to about 1.9-fold coverage. This individual is from a group that shares a common origin with
Neanderthals. This population was not involved in the putative gene flow from Neanderthals into Eurasians; however,
the data suggest that it contributed4–6%of its genetic material to the genomes of present-day Melanesians.Wedesignate
this hominin population ‘Denisovans’ and suggest that it may have been widespread in Asia during the Late Pleistocene
epoch.Atooth found in Denisova Cave carries a mitochondrialgenome highly similar to that of the finger bone. This tooth
shares no derived morphological features with Neanderthals or modern humans, further indicating that Denisovans
have an evolutionary history distinct from Neanderthals and modern humans.
Less than 200,000 years ago, anatomically modern humans (that is,
humans with skeletons similar to those of present-day humans)
appeared in Africa. At that time, as well as later when modern humans
appeared in Eurasia, other ‘archaic’ hominins were already present in
Eurasia. In Europe and westernAsia, hominins defined asNeanderthals
on the basis of their skeletal morphology lived from at least 230,000
years ago before disappearing from the fossil record about 30,000 years
mitochondrial (mt)DNA sequences have been determined from
Neanderthals9–17. This has shown that all Neanderthals studied so
far share a common mtDNA ancestor on the order of 100,000 years
ago10, and in turn, share a common ancestor with the mtDNAs of
present-day humans about 500,000 years ago10,18,19 (as expected, this is
older than the Neanderthal–modern human population split time of
270,000–440,000 years ago estimated from the nuclear genome8). One

62. Most lineages
went extinct
Proconsulidae
Australopithecines
H. erectus
H. neanderthalensis
H. sapiens
Denisovan

63. Stoneking & Krause 2011 Nature Reviews Genetics
? No additional admixture detected despite probable overlap
! detected admixture (location uncertain)
Figure 4 | Dispersal of modern humans from Africa. A mapillustratingtheAfrican origin &GPKUQXC%CXG
of mtDNA !
have 0QGPKUQXCP
of our species, 0GCPFGTVJCN
CFOKZVWTG
the deepest CFOKZVWTG
!
65. Genome-
view7–9, and humans indicate 1WVQH#HTKEC
`[GCTUCIQ
within modern from southern 115
humans first divergences GPKUQXCP
CFOKZVWTG
35–50 kya13,66–of a strong our genome close correlation Stoneking Krause 2011
in a population from strongly implies

64. A WINDING PATH
After early modern humans left Africa around 60,000 years ago (top
right), they spread across the globe and interbred with other
descendants of Homo heidelbergensis.
0
0.8
1.2
1.6
PATCHWORK PLANET
H. sapiens spread from Africa to
western Asia and then to Europe and
southern Asia, eventually reaching
Australasia and the Americas.
Homo floresiensis Denisovans Neanderthals
Most people’s genomes contain remnants of archaic DNA from ancient interbreeding3–6.
2%
98%
Genes*
African
Unknown archaic
African source
Neanderthal
Denisovan
2.5% 2.5% 5%
97.5% 92.5%
*Figures are approximate,
and for Africa, based on
Homo sapiens
2.0
Million years ago
0.4
Homo antecessor
Homo heidelbergensis
Homo erectus
Homo erectus
Wavy branch edges suggest presumed fluctuations in population.
H. floresiensis originated
in an unknown location
and reached remote
parts of Indonesia.
H. erectus spread to western Asia, then
east Asia and Indonesia. Its presence
in Europe is uncertain, but it gave rise
to H. antecessor, found in Spain.
H. heidelbergensis
originated from
H. erectus in an
unknown location
and dispersed across
Africa, southern Asia
and southern Europe.
Stringer 2012 Nature

66. What about today?
Does natural selection (still) act on humans?

67. But...
Triple (?) misunderstandings:
1. Evolution (ie genetic change) is not only through natural
selection
•Drift
• Sexual selection
• ...
2. Medicine can reduce effect of deleterious traits.
•OK many are ‘‘alive who otherwise would have perished’’
•But many still have limited access to medicine.
3. Even with the best medical care
• there are differences in reproductive success

68. Some examples

69. Pathogens/disease
• “Spanish” Flu pandemic of 1918 killed 1-3% of the world’s
population

72. Pathogens/disease
• “Spanish” Flu pandemic of 1918 killed 1-3% of the world’s
population
• AIDS
• Dengue, Typhus, Malaria...

73. Other examples

74. 402.0 612 6 102.0 88.9 3.94***
185.2 16833 106 158.8 49.5 1.17*
112.9 25990 373 69.7 34.4 1.62***
59.6 35613 1069 33.3 25.4 1.79***
22.1 27061 1815 14.9 43.2 1.48***
8.6 10175 2438 4.2 72.9 2.07***
4.6 25619 8784 2.9 49.9 1.58***
2.3 44408 26255 1.7 27.7 1.38***
REPORTS
Deep Human Genealogies Reveal a
Selective Advantage to Be on an
Expanding Wave 40846 Front
40.2
SLSJ
On the basis of the computation Claudia Moreau,1 Claude Bhérer,1 Hélène Vézina,2 Michèle Jomphe,2
front index (WFI) (21), we Damian Labuda,1,3* Laurent Excoffier1,4,5*
of the Saguenay and the lived more often on or close than expected by chance (WFI, regions) (fig. S1). Indeed, 0.75 observed in Lac-Saint-a situation in which half ancestors had lived directly the other half just one generation In contrast, WFI is significantly Charlevoix region (P = 0.003) results are consistent with dynamics of SLSJ and Charlevoix. front was always widespread localitieswere continuously much smaller in Charlevoixwhere remained in the range core (Fig. 1). New immigrants constituted an important minority getting married, with a greater settling on the wave range core, especially before the wave front and up to 10% 7.4 39 15 2.6 99.6 2.8***
4.6 15444 4420 3.5 62.3 1.3***
2.4 35777 19726 1.8 30.9 1.3***
Since their origin, human populations have colonized the whole planet, but the demographic
processes governing range expansions 24161 are mostly unknown. We analyzed the genealogy 45.1
of more
than one million individuals resulting from a range expansion in Quebec between 1686 and 1960
and reconstructed the spatial dynamics of the expansion. We find that a majority of the present
Saguenay Lac-Saint-Jean population can be traced back to ancestors having lived directly on or
close to the wave front. Ancestors located on the front contributed significantly more to the current
gene pool than those from the range core, likely due to a 20% larger effective fertility of women
on the wave front. This fitness component is heritable on the wave front and not in the core,
implying that this life-history trait evolves during range expansions.
Most species go through environmental-ly
induced range expansions or range
shifts (1), promoting the evolution of
traits associated with dispersal and reproduction
(2). Humans likely colonized the world by a
series of range expansions from Africa (3), pos-sibly
with episodes of interbreeding with now
extinct hominins (4, 5), leading to allele frequen-cy
and heterozygosity clines from entry points
Quebec parish registers that document the recent
temporal and spatial expansion of the settle-ment
of the Charlevoix Saguenay Lac-Saint-
Jean (ChSLSJ) region, northeast of Quebec City,
Canada: a prime example of a recent, fast, and
well-documented range expansion (17) (Fig. 1).
The European colonization of Quebec was ini-tiated
in 1608 with the foundation of Quebec
City, and the colony was well established by the
tracing back the founding events As shown in Fig. 1, the inferred is a mixture of long-creating an irregular wave more progressive, short-which then filled gaps and wave front.
genes
genera-tion
all
between
and
that
the
genes
in
alleles
or
similar
Table 2. Age of reproduction and number of children of women fromSLSJ in the period 1840 to 1900.
Note that this table only includes women with known birth dates, such that age at marriage can be
computed.
No. of
women
Mean no. of
children
(FS)
Mean no. of
married
children
(EFS)
Mean age at
marriage
FS ratio
WF/RC
EFS ratio
WF/RC
Marriage
age ratio
WF/RC
Wave front (WF) 2663 9.1 4.9 20.5
1.15*** 1.20*** 0.95***
Range core (RC) 1783 7.9 4.1 21.6
***, t test of difference between means; P 0.001

76. Natural selection in a contemporary
human population
Sean G. Byarsa, Douglas Ewbankb, Diddahally R. Govindarajuc, and Stephen C. Stearnsa,1
aDepartment of Ecology and Evolutionary Biology, Yale University, New Haven, CT 06520-8102; bPopulation Studies Center, University Philadelphia, PA 19104-6299; and cDepartment of Neurology, Boston University School of Medicine, Boston, MA 02118-2526
Edited by Peter T. Ellison, Harvard University, Cambridge, MA, and approved September 16, 2009 (received for review June 25, Our aims were to demonstrate that natural selection is operating
on contemporary humans, predict future evolutionary change for
specific traits with medical significance, and show that for some
traits we can make short-term predictions about our future evolu-tion.
To do so, we measured the strength of selection, estimated
genetic variation and covariation, and predicted the response to
selection for women in the Framingham Heart Study, a project of
the National Heart, Lung, and Blood Institute and Boston Univer-sity
that began in 1948. We found that natural selection is acting
to cause slow, gradual evolutionary change. The descendants of
these women are predicted to be on average slightly shorter and
stouter, to have lower total cholesterol levels and systolic blood
pressure, to have their first child earlier, and to reach menopause
later than they would in the absence of evolution. Selection is
tending to lengthen the reproductive period at both ends. To
better understand and predict such changes, the design of planned
large, long-term, multicohort studies should include input from
evolutionary biologists.
evolutionary rates | heritability | Homo sapiens | medical traits
to identify factors that contribute It is the longest running multigenerational 5000 history. The people people originally
enrolled European ancestry (20% their Ireland, 10% kids;
Italy, 10% Quebec). The 5,209) has been examined every 2 years, 70 between traits 1948 and been examined approximately measured
2008. The offspring every 4 years, every between 1971 2-and 4 years
2008 (4). There is cohort (n = 4,095) that is not included in since in it have not many physical 1948.
yet completed reproduction. and blood chemistry traits questionnaire is administered, yielding are deidentified by the FHS and delivered Institutes of Health dbGaP database, them for analysis. In this study, individuals who were measured three or Measuring Selection in a Multicohort Natural selection has been measured populations of animals and plants (5) using

77. NATURE REVIEWS | GENETICS VOLUME 11 | FEBRUARY 2010 | 137
How culture shaped the human
genome: bringing genetics and
the human sciences together
Kevin N. Laland*, John Odling-Smee‡ and Sean Myles§ ||
Abstract | Researchers from diverse backgrounds are converging on the view that human
evolution has been shaped by gene–culture interactions. Theoretical biologists have
used population genetic models to demonstrate that cultural processes can have a
profound effect on human evolution, and anthropologists are investigating cultural
practices that modify current selection. These findings are supported by recent analyses
of human genetic variation, which reveal that hundreds of genes have been subject to
recent positive selection, often in response to human activities. Here, we collate these
data, highlighting the considerable potential for cross-disciplinary exchange to provide
novel insights into how culture has shaped the human genome.
Accounts of human evolution frequently assume that
the selective events that shaped us were changes in the
adult lactose tolerance12,13,15,16. Estimates for the number
of human genes that have been subject to recent rapid

78. Genetics of our behavior?

79. Evolutionary Psychology
• Generosity higher if
affects reputation
!
!
• Pheromones help identify our mates based on MHC

81. Summary
• Human evolution is complicated but fascinating!
• (just like any other species!!)

82. For more info
• http://humanorigins.si.edu/ (Smithonian Institution)
• PBS Nova Becoming Human (on youtube)
• Stoneking Krause. Learning about human population history
from ancient and modern genomes. Nature Reviews Genetics
2011.

83. Any questions
About first lectures?