History of life on earth If the earth was 24 hours old then animals didnt appear until the last 2 hours dinosaurs went extinct in the the last 20 minutes anatomically modern humans the last one or two seconds ID: 524530
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Slide1
Adam & Eve & GeneticsSlide2
History of life on earth
If the earth was 24 hours old
,
then
animals didn’t appear until the last 2 hours
dinosaurs went extinct in the the last 20 minutes –
anatomically modern humans -- the last one or two seconds
recorded history, about last 0.1s
your lifespan, the last millisecondSlide3
Common descent in biology?
Page from Darwin's notebooks ~ circa1837 showing his first known sketch of an evolutionary tree depicting common descent.Slide4
Case study 2: evolution of horses
Can sound like weak inductive reasoning to many physical scientists
homologiesSlide5
Divergence of the chimpanzee and human lineages occurred about 6 million years ago; the times of lineage divergence are not to scale
News & Views: The chimpanzee and us
, Wen-Hsiung Li and Matthew A. Saunders, Nature 437, 50-51 (1September 2005)
.
Case study 3: common descent of human & chimp?Slide6
tapestry arguments in biology: chromosomal banding:
The origin of man: a chromosomal pictorial legacy.
J.J Yunis and O. Prakash, Science
215
, 1525 (1982)
Humans have 46 (2 X 23) chromosomes
Apes have 48 (2 X 24) chromosomes
chromosome 2: Human, Chimp, Gorilla, Orang-utanSlide7
tapestry arguments in biology: fusion of chromosome 2?
chromosome 2: Human, Chimp, Gorilla, Orang-utanSlide8
tapestry arguments in biology: evidence from the human genome
Chromosome 2 is unique to the human lineage of evolution, having emerged as a result of head-to-head fusion of two acrocentric chromosomes that remained separate in other primates. The precise fusion site has been located in 2q13−2q14.1 (ref. 2; hg16:114,455,8
23
−114,455,8
38
), where our analysis confirmed the presence of multiple subtelomeric duplications to chromosomes 1, 5, 8, 9, 10, 12, 19, 21 and 22 (Fig. 3; Supplementary Fig. 3a, region A). During the formation of human chromosome 2, one of the two centromeres became inactivated (2q21, which corresponds to the centromere from chimp chromosome 13) and the centromeric structure quickly deterioriated [42].
Generation and annotation of the DNA sequences of human chromosomes 2 and 4
, L.W. Hillier et al., Nature 434,
724
(2005).Slide9
endogenous retroviruses
In humans endogenous retrovirus sequences make up about 1% of the genome.
Lebedev, Y. B., et al. (2000) "Differences in HERV-K LTR insertions in orthologous loci of humans and great apes." Gene 247: 265-277.
HERV-K insertionsSlide10
tapestry arguments in biology: more threads of evidence
Genetic threads
SINEs (Alu )
LINEs
Retroviral insertions
pseudo genes (e.g. olefaction)chromosomal inversionsPhenotypal similaritiesFossilsSlide11Slide12
Human brain size & out of AfricaSlide13
Mitochondrial eve (150,000 -200,000 years)
Y-Chromosome Adam (50,00-80,000 years)
Not the only individualSlide14
Population size with time
PSMC estimate on data simulated by
msHOT
. The blue curve is the population-size history used in simulation; the red curve is the PSMC estimate on the originally simulated sequence; the 100 thin green curves are the PSMC estimates on 100 sequences randomly resampled from the original sequence.
b
, PSMC estimate on data with a variable mutation rate or with hotspots. g, generation time; μ, mutation rate.
Heng
Li & Richard Durbin Nature 475, 493–496 (13 July 2011)